From 6ffe548f8c708286f9c430ad5fbcc769cb7d2b50 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Mon, 2 Feb 2026 23:26:45 +0000
Subject: [PATCH 1/9] saving current state

---
 examples/CMakeLists.txt              |    1 +
 src/beman/execution/execution.cppm   | 6466 +-------------------------
 tests/beman/execution/CMakeLists.txt |    1 +
 3 files changed, 8 insertions(+), 6460 deletions(-)

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index c68e6e17..c5bfc674 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -33,6 +33,7 @@ set(EXAMPLES
     stopping
     when_all-cancel
 )
+set(EXAMPLES)
 
 if(BEMAN_USE_MODULES)
     list(APPEND EXAMPLES modules) # modules.cpp
diff --git a/src/beman/execution/execution.cppm b/src/beman/execution/execution.cppm
index e54eb38a..a30cef80 100644
--- a/src/beman/execution/execution.cppm
+++ b/src/beman/execution/execution.cppm
@@ -5,6468 +5,14 @@ module;
 // *****************************************************;
 // generated by ./bin/mk-module.py src/beman/execution/execution.cppm
 
-#include <beman/execution/modules_export.hpp>
-#include <cassert>
-
-#ifdef BEMAN_HAS_IMPORT_STD
-import std;
-#else
-#line 239 "./bin/mk-module.py"
-#include <algorithm>
-#line 239 "./bin/mk-module.py"
-#include <atomic>
-#line 239 "./bin/mk-module.py"
-#include <cassert>
-#line 239 "./bin/mk-module.py"
-#include <concepts>
-#line 239 "./bin/mk-module.py"
-#include <condition_variable>
-#line 239 "./bin/mk-module.py"
-#include <coroutine>
-#line 239 "./bin/mk-module.py"
-#include <cstddef>
-#line 239 "./bin/mk-module.py"
-#include <cstdlib>
-#line 239 "./bin/mk-module.py"
-#include <exception>
-#line 239 "./bin/mk-module.py"
-#include <functional>
-#line 239 "./bin/mk-module.py"
-#include <memory>
-#line 239 "./bin/mk-module.py"
-#include <mutex>
-#line 239 "./bin/mk-module.py"
-#include <optional>
-#line 239 "./bin/mk-module.py"
-#include <system_error>
-#line 239 "./bin/mk-module.py"
-#include <thread>
-#line 239 "./bin/mk-module.py"
-#include <tuple>
-#line 239 "./bin/mk-module.py"
-#include <type_traits>
-#line 239 "./bin/mk-module.py"
-#include <utility>
-#line 239 "./bin/mk-module.py"
-#include <variant>
-#endif
+#include <beman/execution/execution.hpp>
 
 export module beman.execution;
 
-#line 5 "include/beman/execution/execution.hpp"
-
-#line 9 "include/beman/execution/detail/common.hpp"
-#ifndef BEMAN_EXECUTION_EXPORT
-#define BEMAN_EXECUTION_EXPORT
-#endif
-
-#if defined(disabled__cpp_deleted_function)
-#define BEMAN_EXECUTION_DELETE(msg) delete (msg)
-#else
-#define BEMAN_EXECUTION_DELETE(msg) delete
-#endif
-
-#line 43 "include/beman/execution/detail/common.hpp"
-namespace beman {
-
-#line 54 "include/beman/execution/detail/common.hpp"
-namespace execution {
-
-#line 61 "include/beman/execution/detail/common.hpp"
-namespace detail {}
-} // namespace execution
-} // namespace beman
-
-#line 6 "include/beman/execution/detail/suppress_push.hpp"
-#if defined(__GNUC__)
-#define BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wmissing-braces"
-#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
-#endif
-
-#if defined(__clang__)
-#define BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunknown-warning-option"
-#pragma clang diagnostic ignored "-Wmissing-braces"
-#pragma clang diagnostic ignored "-Wc++26-extensions"
-#endif
-#line 3 "include/beman/execution/detail/suppress_pop.hpp"
-
-#line 6 "include/beman/execution/detail/suppress_pop.hpp"
-#ifdef BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
-#if defined(__GNUC__)
-#pragma GCC diagnostic pop
-#endif
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-#undef BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
-#endif
-#line 3 "include/beman/execution/detail/queryable.hpp"
-
-#line 12 "include/beman/execution/detail/queryable.hpp"
-namespace beman::execution::detail {
-template <typename T>
-concept queryable = ::std::destructible<T>;
-}
-#line 14 "include/beman/execution/detail/forwarding_query.hpp"
-namespace beman::execution::detail {
-
-#line 20 "include/beman/execution/detail/forwarding_query.hpp"
-struct forwarding_query_t {
-    template <typename Object>
-        requires requires(Object&& object, const forwarding_query_t& query) {
-            { ::std::forward<Object>(object).query(query) } noexcept -> ::std::same_as<bool>;
-        }
-    constexpr auto operator()(Object&& object) const noexcept -> bool {
-        return ::std::forward<Object>(object).query(*this);
-    }
-    template <typename Object>
-    constexpr auto operator()(Object&&) const noexcept -> bool {
-        return ::std::derived_from<::std::remove_cvref_t<Object>, ::beman::execution::detail::forwarding_query_t>;
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-
-#line 40 "include/beman/execution/detail/forwarding_query.hpp"
-export /* --------- */ using forwarding_query_t = beman::execution::detail::forwarding_query_t;
-
-#line 53 "include/beman/execution/detail/forwarding_query.hpp"
-export /* --------- */ inline constexpr forwarding_query_t forwarding_query{};
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/movable_value.hpp"
-namespace beman::execution::detail {
-template <typename T>
-concept movable_value =
-    ::std::move_constructible<::std::decay_t<T>> && ::std::constructible_from<::std::decay_t<T>, T> &&
-    (!::std::is_array_v<::std::remove_reference_t<T>>);
-}
-#line 12 "include/beman/execution/detail/matching_sig.hpp"
-namespace beman::execution::detail {
-template <typename Fun>
-struct matching_sig_transform {
-    using type = Fun;
-};
-template <typename Return, typename... Args>
-struct matching_sig_transform<Return(Args...)> {
-    using type = Return(Args&&...);
-};
-
-template <typename Fun1, typename Fun2>
-inline constexpr bool matching_sig =
-    ::std::same_as<typename ::beman::execution::detail::matching_sig_transform<Fun1>::type,
-                   typename ::beman::execution::detail::matching_sig_transform<Fun2>::type>;
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/as_except_ptr.hpp"
-namespace beman::execution::detail {
-
-#line 23 "include/beman/execution/detail/as_except_ptr.hpp"
-template <typename Error>
-decltype(auto) as_except_ptr(Error&& error) {
-    if constexpr (::std::same_as<::std::exception_ptr, ::std::decay_t<Error>>) {
-        return ::std::forward<Error>(error);
-    } else if constexpr (::std::same_as<::std::error_code, ::std::decay_t<Error>>) {
-        return ::std::make_exception_ptr(::std::system_error(error));
-    } else {
-        return ::std::make_exception_ptr(::std::forward<Error>(error));
-    }
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/set_value.hpp"
-namespace beman::execution {
-
-#line 19 "include/beman/execution/detail/set_value.hpp"
-export /* --------- */ struct set_value_t {
-    template <typename Receiver, typename... Args>
-    auto operator()(Receiver&, Args&&...) const
-        -> void = BEMAN_EXECUTION_DELETE("set_value requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver, typename... Args>
-    auto operator()(const Receiver&&, Args&&...) const
-        -> void = BEMAN_EXECUTION_DELETE("set_value requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver, typename... Args>
-    auto operator()(Receiver&&, Args&&...) const -> void
-        requires(not requires(Receiver&& receiver, Args&&... args) {
-                    ::std::forward<Receiver>(receiver).set_value(::std::forward<Args>(args)...);
-                })
-    = BEMAN_EXECUTION_DELETE("set_value requires a suitable member overload on the receiver");
-    template <typename Receiver, typename... Args>
-        requires(not noexcept(::std::declval<Receiver>().set_value(::std::declval<Args>()...)))
-    auto operator()(Receiver&&, Args&&...) const
-        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_value(args...) has to be noexcept");
-
-    template <typename Receiver, typename... Args>
-    auto operator()(Receiver&& receiver, Args&&... args) const noexcept -> void {
-        ::std::forward<Receiver>(receiver).set_value(::std::forward<Args>(args)...);
-    }
-};
-
-#line 47 "include/beman/execution/detail/set_value.hpp"
-export /* --------- */ inline constexpr set_value_t set_value{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/set_error.hpp"
-namespace beman::execution {
-
-#line 19 "include/beman/execution/detail/set_error.hpp"
-export /* --------- */ struct set_error_t {
-    template <typename Receiver, typename Error>
-    auto operator()(Receiver&, Error&&) const
-        -> void = BEMAN_EXECUTION_DELETE("set_error requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver, typename Error>
-    auto operator()(const Receiver&&, Error&&) const
-        -> void = BEMAN_EXECUTION_DELETE("set_error requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver, typename Error>
-    auto operator()(Receiver&&, Error&&) const -> void
-        requires(not requires(Receiver&& receiver, Error&& error) {
-                    ::std::forward<Receiver>(receiver).set_error(::std::forward<Error>(error));
-                })
-    = BEMAN_EXECUTION_DELETE("set_error requires a suitable member overload on the receiver");
-    template <typename Receiver, typename Error>
-        requires(not noexcept(::std::declval<Receiver>().set_error(::std::declval<Error>())))
-    auto operator()(Receiver&&, Error&&) const
-        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_error(error) has to be noexcept");
-
-    // NOLINTBEGIN(misc-no-recursion)
-    template <typename Receiver, typename Error>
-    auto operator()(Receiver&& receiver, Error&& error) const noexcept -> void {
-        ::std::forward<Receiver>(receiver).set_error(::std::forward<Error>(error));
-    }
-    // NOLINTEND(misc-no-recursion)
-};
-
-#line 49 "include/beman/execution/detail/set_error.hpp"
-export /* --------- */ inline constexpr set_error_t set_error{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/set_stopped.hpp"
-namespace beman::execution {
-
-#line 19 "include/beman/execution/detail/set_stopped.hpp"
-export /* --------- */ struct set_stopped_t {
-    template <typename Receiver>
-    auto operator()(Receiver&) const
-        -> void = BEMAN_EXECUTION_DELETE("set_stopped requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver>
-    auto operator()(const Receiver&&) const
-        -> void = BEMAN_EXECUTION_DELETE("set_stopped requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver>
-    auto operator()(Receiver&&) const -> void
-        requires(not requires(Receiver&& receiver) { ::std::forward<Receiver>(receiver).set_stopped(); })
-    = BEMAN_EXECUTION_DELETE("set_stopped requires a suitable member overload on the receiver");
-    template <typename Receiver>
-        requires(not noexcept(::std::declval<Receiver>().set_stopped()))
-    auto operator()(Receiver&&) const
-        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_stopped() has to be noexcept");
-
-    template <typename Receiver>
-    auto operator()(Receiver&& receiver) const noexcept -> void {
-        ::std::forward<Receiver>(receiver).set_stopped();
-    }
-};
-
-#line 45 "include/beman/execution/detail/set_stopped.hpp"
-export /* --------- */ inline constexpr set_stopped_t set_stopped{};
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/start.hpp"
-namespace beman::execution {
-export /* --------- */ struct start_t {
-    template <typename State>
-    auto operator()(State&&) const -> void = BEMAN_EXECUTION_DELETE("start(obj) requires an lvalue argument");
-    template <typename State>
-        requires(not requires(State& state) { state.start(); })
-    auto operator()(State&) const -> void = BEMAN_EXECUTION_DELETE("state needs to have a start() member");
-    template <typename State>
-        requires(not requires(const State& state) { state.start(); })
-    auto operator()(const State&) const -> void = BEMAN_EXECUTION_DELETE("state needs to have a start() member");
-
-    template <typename State>
-        requires(not requires(State& state) {
-                    { state.start() } noexcept;
-                })
-    auto operator()(State&) const -> void = BEMAN_EXECUTION_DELETE("state start() member has to be noexcept");
-    template <typename State>
-        requires(not requires(const State& state) {
-                    { state.start() } noexcept;
-                })
-    auto operator()(const State&) const -> void = BEMAN_EXECUTION_DELETE("state start() member has to be noexcept");
-
-    template <typename State>
-    auto operator()(const State& state) const noexcept -> void {
-        state.start();
-    }
-    // NOLINTBEGIN(misc-no-recursion)
-    template <typename State>
-    auto operator()(State& state) const noexcept -> void {
-        state.start();
-    }
-    // NOLINTEND(misc-no-recursion)
-};
-
-export /* --------- */ inline constexpr start_t start{};
-} // namespace beman::execution
-
-#line 11 "include/beman/execution/detail/non_assignable.hpp"
-namespace beman::execution::detail {
-struct non_assignable;
-}
-#line 17 "include/beman/execution/detail/non_assignable.hpp"
-struct beman::execution::detail::non_assignable {
-    non_assignable()                                         = default;
-    non_assignable(non_assignable&&)                         = default;
-    non_assignable(const non_assignable&)                    = default;
-    auto operator=(non_assignable&&) -> non_assignable&      = delete;
-    auto operator=(const non_assignable&) -> non_assignable& = delete;
-};
-
-#line 13 "include/beman/execution/detail/simple_allocator.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <typename Alloc>
-concept simple_allocator =
-    requires(::std::remove_cvref_t<Alloc> alloc, ::std::size_t n) {
-        { *alloc.allocate(n) } -> ::std::same_as<typename ::std::remove_cvref_t<Alloc>::value_type&>;
-        alloc.deallocate(alloc.allocate(n), n);
-    } && ::std::copy_constructible<::std::remove_cvref_t<Alloc>> &&
-    ::std::equality_comparable<::std::remove_cvref_t<Alloc>>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/never_stop_token.hpp"
-namespace beman::execution {
-export /* --------- */ class never_stop_token;
-}
-#line 17 "include/beman/execution/detail/never_stop_token.hpp"
-class beman::execution::never_stop_token {
-    struct private_callback_type {
-        explicit private_callback_type(never_stop_token, auto&&) noexcept {}
-    };
-
-  public:
-    template <typename>
-    using callback_type = private_callback_type;
-
-    static constexpr auto stop_requested() noexcept -> bool { return {}; }
-    static constexpr auto stop_possible() noexcept -> bool { return {}; }
-    auto                  operator==(const never_stop_token&) const -> bool = default;
-};
-
-#line 12 "include/beman/execution/detail/decayed_same_as.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/decayed_same_as.hpp"
-template <typename T0, typename T1>
-concept decayed_same_as = ::std::same_as<::std::remove_cvref_t<T0>, ::std::remove_cvref_t<T1>>;
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/callable.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/callable.hpp"
-template <typename Fun, typename... Args>
-concept callable = requires(Fun&& fun, Args&&... args) { ::std::forward<Fun>(fun)(::std::forward<Args>(args)...); };
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/forward_like.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct forward_like_helper;
-
-template <typename T>
-struct forward_like_helper {
-    template <typename U>
-    static auto forward(U&& u) -> ::std::remove_reference_t<U>&& {
-        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
-    }
-};
-template <typename T>
-struct forward_like_helper<T&&> {
-    template <typename U>
-    static auto forward(U&& u) -> ::std::remove_cvref_t<U>&& {
-        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
-    }
-};
-template <typename T>
-struct forward_like_helper<T&> {
-    template <typename U>
-    static auto forward(U&& u) -> ::std::remove_cvref_t<U>& {
-        return ::std::forward<U&&>(u);
-    }
-};
-template <typename T>
-struct forward_like_helper<const T&&> {
-    template <typename U>
-    static auto forward(U&& u) -> const ::std::remove_cvref_t<U>&& {
-        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
-    }
-};
-template <typename T>
-struct forward_like_helper<const T&> {
-    template <typename U>
-    static auto forward(U&& u) -> const ::std::remove_cvref_t<U>& {
-        return ::std::forward<U&&>(u);
-    }
-};
-
-#line 57 "include/beman/execution/detail/forward_like.hpp"
-template <typename T, typename U>
-auto own_forward_like(U&& u) noexcept -> decltype(auto) {
-    return ::beman::execution::detail::forward_like_helper<T>::forward(::std::forward<U>(u));
-}
-#line 67 "include/beman/execution/detail/forward_like.hpp"
-template <typename T, typename U>
-auto forward_like(U&& u) noexcept -> decltype(auto) {
-#if 202207 <= disabled__cpp_lib_forward_like
-    return ::std::forward_like<T>(::std::forward<U>(u));
-#else
-    return ::beman::execution::detail::forward_like_helper<T>::forward(::std::forward<U>(u));
-#endif
-}
-#line 76 "include/beman/execution/detail/forward_like.hpp"
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/join_env.hpp"
-namespace beman::execution::detail {
-template <typename Env1, typename Env2>
-class join_env {
-  private:
-    Env1 env1;
-    Env2 env2;
-
-  public:
-    template <typename E1, typename E2>
-    join_env(E1&& e1, E2&& e2) : env1(::std::forward<E1>(e1)), env2(::std::forward<E2>(e2)) {}
-
-    template <typename Query, typename... Args>
-        requires requires(Env1&, const Query& query, Args&&... args) {
-            env1.query(query, ::std::forward<Args>(args)...);
-        }
-    auto query(const Query& query, Args&&... args) noexcept -> decltype(auto) {
-        return this->env1.query(query, ::std::forward<Args>(args)...);
-    }
-    template <typename Query, typename... Args>
-        requires(
-            not requires(Env1&, const Query& query, Args&&... args) {
-                env1.query(query, ::std::forward<Args>(args)...);
-            } &&
-            requires(Env2& e2, const Query& query, Args&&... args) { e2.query(query, ::std::forward<Args>(args)...); })
-    auto query(const Query& query, Args&&... args) noexcept -> decltype(auto) {
-        return this->env2.query(query, ::std::forward<Args>(args)...);
-    }
-    template <typename Query, typename... Args>
-        requires requires(const Env1& e1, const Query& query, Args&&... args) {
-            { e1.query(query, ::std::forward<Args>(args)...) } noexcept;
-        }
-    auto query(const Query& query, Args&&... args) const noexcept -> decltype(auto) {
-        return this->env1.query(query, ::std::forward<Args>(args)...);
-    }
-    template <typename Query, typename... Args>
-        requires(
-            not requires(const Env1& e1, const Query& query, Args&&... args) {
-                { e1.query(query, ::std::forward<Args>(args)...) } noexcept;
-            } &&
-            requires(const Env2& e2, const Query& query, Args&&... args) {
-                { e2.query(query, ::std::forward<Args>(args)...) } noexcept;
-            })
-    auto query(const Query& query, Args&&... args) const noexcept -> decltype(auto) {
-        return this->env2.query(query, ::std::forward<Args>(args)...);
-    }
-};
-
-template <typename Env1, typename Env2>
-join_env(Env1&&, Env2&&) -> join_env<::std::remove_cvref_t<Env1>, ::std::remove_cvref_t<Env2>>;
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/product_type.hpp"
-namespace beman::execution::detail {
-
-template <::std::size_t I, typename T>
-struct product_type_element {
-    T    value;
-    auto operator==(const product_type_element&) const -> bool = default;
-};
-
-template <typename, typename...>
-struct product_type_base;
-
-template <::std::size_t... I, typename... T>
-struct product_type_base<::std::index_sequence<I...>, T...>
-    : ::beman::execution::detail::product_type_element<I, T>... {
-    static constexpr ::std::size_t size() { return sizeof...(T); }
-    static constexpr bool          is_product_type{true};
-
-    template <::std::size_t J, typename S>
-    static auto element_get(::beman::execution::detail::product_type_element<J, S>& self) noexcept -> S& {
-        return self.value;
-    }
-    template <::std::size_t J, typename S>
-    static auto element_get(::beman::execution::detail::product_type_element<J, S>&& self) noexcept -> S&& {
-        return ::std::move(self.value);
-    }
-    template <::std::size_t J, typename S>
-    static auto element_get(const ::beman::execution::detail::product_type_element<J, S>& self) noexcept -> const S& {
-        return self.value;
-    }
-#line 45 "include/beman/execution/detail/product_type.hpp"
-    template <::std::size_t J>
-    auto get() & -> decltype(auto) {
-        return this->element_get<J>(*this);
-    }
-    template <::std::size_t J>
-    auto get() && -> decltype(auto) {
-        return this->element_get<J>(::std::move(*this));
-    }
-    template <::std::size_t J>
-    auto get() const& -> decltype(auto) {
-        return this->element_get<J>(*this);
-    }
-#line 58 "include/beman/execution/detail/product_type.hpp"
-    template <::std::size_t J, typename Allocator, typename Self>
-    static auto make_element(Allocator&& alloc, Self&& self) -> decltype(auto) {
-        using type = ::std::remove_cvref_t<decltype(product_type_base::element_get<J>(std::forward<Self>(self)))>;
-        if constexpr (::std::uses_allocator_v<type, Allocator>)
-            return ::std::make_obj_using_allocator<type>(alloc,
-                                                         product_type_base::element_get<J>(std::forward<Self>(self)));
-        else
-            return product_type_base::element_get<J>(std::forward<Self>(self));
-    }
-#line 68 "include/beman/execution/detail/product_type.hpp"
-    auto operator==(const product_type_base&) const -> bool = default;
-};
-
-template <typename T>
-concept is_product_type_c = requires(const T& t) { T::is_product_type; };
-
-template <typename... T>
-struct product_type : ::beman::execution::detail::product_type_base<::std::index_sequence_for<T...>, T...> {
-    template <typename Allocator, typename Product, std::size_t... I>
-    static auto make_from(Allocator&& allocator, Product&& product, std::index_sequence<I...>) -> product_type {
-        return {product_type::template make_element<I>(allocator, ::std::forward<Product>(product))...};
-    }
-#line 81 "include/beman/execution/detail/product_type.hpp"
-    template <typename Allocator, typename Product>
-    static auto make_from(Allocator&& allocator, Product&& product) -> product_type {
-        return product_type::make_from(
-            ::std::forward<Allocator>(allocator), ::std::forward<Product>(product), ::std::index_sequence_for<T...>{});
-    }
-#line 87 "include/beman/execution/detail/product_type.hpp"
-    template <typename Fun, ::std::size_t... I>
-    constexpr auto apply_elements(::std::index_sequence<I...>, Fun&& fun) const -> decltype(auto) {
-        return ::std::forward<Fun>(fun)(this->template get<I>()...);
-    }
-    template <typename Fun>
-    constexpr auto apply(Fun&& fun) const -> decltype(auto) {
-        return apply_elements(::std::index_sequence_for<T...>{}, ::std::forward<Fun>(fun));
-    }
-    template <typename Fun, ::std::size_t... I>
-    constexpr auto apply_elements(::std::index_sequence<I...>, Fun&& fun) -> decltype(auto) {
-
-        return ::std::forward<Fun>(fun)(std::move(this->template get<I>())...);
-    }
-    template <typename Fun>
-    constexpr auto apply(Fun&& fun) -> decltype(auto) {
-        return apply_elements(::std::index_sequence_for<T...>{}, ::std::forward<Fun>(fun));
-    }
-};
-template <typename... T>
-product_type(T&&...) -> product_type<::std::decay_t<T>...>;
-
-template <typename T>
-constexpr auto is_product_type(const T&) -> ::std::false_type {
-    return {};
-}
-template <typename... T>
-constexpr auto is_product_type(const ::beman::execution::detail::product_type<T...>&) -> ::std::true_type {
-    return {};
-}
-#line 117 "include/beman/execution/detail/product_type.hpp"
-template <::std::size_t Start, typename Fun, typename Tuple, ::std::size_t... I>
-constexpr auto sub_apply_helper(Fun&& fun, Tuple&& tuple, ::std::index_sequence<I...>) -> decltype(auto) {
-    // NOLINTNEXTLINE(bugprone-use-after-move,hicpp-invalid-access-moved)
-    return ::std::forward<Fun>(fun)(::std::forward<Tuple>(tuple).template get<I + Start>()...);
-}
-#line 123 "include/beman/execution/detail/product_type.hpp"
-template <::std::size_t Start, typename Fun, typename Tuple>
-constexpr auto sub_apply(Fun&& fun, Tuple&& tuple) -> decltype(auto) {
-    constexpr ::std::size_t TSize{::std::tuple_size_v<::std::remove_cvref_t<Tuple>>};
-    static_assert(Start <= TSize);
-    return sub_apply_helper<Start>(
-        ::std::forward<Fun>(fun), ::std::forward<Tuple>(tuple), ::std::make_index_sequence<TSize - Start>());
-}
-#line 131 "include/beman/execution/detail/product_type.hpp"
-} // namespace beman::execution::detail
-
-namespace std {
-template <typename T>
-    requires ::beman::execution::detail::is_product_type_c<T>
-struct tuple_size<T> : ::std::integral_constant<std::size_t, T::size()> {};
-
-template <::std::size_t I, typename T>
-    requires ::beman::execution::detail::is_product_type_c<T>
-struct tuple_element<I, T> {
-    using type = ::std::decay_t<decltype(::std::declval<T>().template get<I>())>;
-};
-} // namespace std
-
-#line 12 "include/beman/execution/detail/query_with_default.hpp"
-namespace beman::execution::detail {
-template <typename Tag, typename Env, typename Value>
-    requires requires(const Tag& tag, const Env& env) { tag(env); }
-constexpr auto query_with_default(Tag, const Env& env, Value&&) noexcept(noexcept(Tag()(env))) -> decltype(auto) {
-    return Tag()(env);
-}
-#line 19 "include/beman/execution/detail/query_with_default.hpp"
-template <typename Tag, typename Env, typename Value>
-constexpr auto
-query_with_default(Tag, const Env&, Value&& value) noexcept(noexcept(static_cast<Value>(std::forward<Value>(value))))
-    -> decltype(auto) {
-    return static_cast<Value>(std::forward<Value>(value));
-}
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/child_type.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/child_type.hpp"
-template <typename Sender, ::std::size_t I = 0u>
-using child_type = decltype(::std::declval<Sender>().template get<I + 2>());
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/decayed_tuple.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/decayed_tuple.hpp"
-template <typename... T>
-using decayed_tuple = ::std::tuple<::std::decay_t<T>...>;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/make_env.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <typename Query, typename Value>
-class make_env {
-  private:
-    Value value;
-
-  public:
-    template <typename V>
-    make_env(const Query&, V&& v) : value(::std::forward<V>(v)) {}
-    constexpr auto query(const Query&) const noexcept -> const Value& { return this->value; }
-    constexpr auto query(const Query&) noexcept -> Value& { return this->value; }
-};
-template <typename Query, typename Value>
-make_env(Query&&, Value&& value) -> make_env<::std::remove_cvref_t<Query>, ::std::remove_cvref_t<Value>>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/meta_prepend.hpp"
-namespace beman::execution::detail::meta::detail {
-template <typename, typename>
-struct prepend;
-
-template <template <typename...> class List, typename H, typename... T>
-struct prepend<H, List<T...>> {
-    using type = List<H, T...>;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <typename H, typename Tail>
-using prepend = typename ::beman::execution::detail::meta::detail::prepend<H, Tail>::type;
-}
-#line 11 "include/beman/execution/detail/meta_to.hpp"
-namespace beman::execution::detail::meta {
-template <template <typename...> class To, typename>
-struct to_type_list;
-template <template <typename...> class To, template <typename...> class List, typename... T>
-struct to_type_list<To, List<T...>> {
-    using type = To<T...>;
-};
-template <template <typename...> class To, typename T>
-using to = typename ::beman::execution::detail::meta::to_type_list<To, T>::type;
-} // namespace beman::execution::detail::meta
-
-#line 11 "include/beman/execution/detail/type_list.hpp"
-namespace beman::execution::detail {
-template <typename...>
-struct type_list {};
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/stop_callback_for_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <class Token, class CallbackFun>
-using stop_callback_for_t = typename Token::template callback_type<CallbackFun>;
-}
-#line 17 "include/beman/execution/detail/stop_callback_for_t.hpp"
-namespace beman::execution::detail {
-template <typename CallbackFun, typename Token, typename Initializer = CallbackFun>
-concept stoppable_callback_for =
-    ::std::invocable<CallbackFun> && ::std::constructible_from<CallbackFun, Initializer> &&
-    requires { typename ::beman::execution::stop_callback_for_t<Token, CallbackFun>; } &&
-    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, Token, Initializer> &&
-    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, Token&, Initializer> &&
-    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, const Token&, Initializer>;
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/call_result_t.hpp"
-namespace beman::execution::detail {
-template <typename Fun, typename... Args>
-
-#line 19 "include/beman/execution/detail/call_result_t.hpp"
-using call_result_t = decltype(::std::declval<Fun>()(std::declval<Args>()...));
-} // namespace beman::execution::detail
-#line 12 "include/beman/execution/detail/meta_size.hpp"
-namespace beman::execution::detail::meta {
-template <typename>
-struct size;
-template <template <typename...> class L, typename... T>
-struct size<L<T...>> {
-    static constexpr ::std::size_t value{sizeof...(T)};
-};
-template <typename T>
-inline constexpr ::std::size_t size_v{::beman::execution::detail::meta::size<T>::value};
-} // namespace beman::execution::detail::meta
-
-#line 11 "include/beman/execution/detail/on_stop_request.hpp"
-namespace beman::execution::detail {
-template <typename St>
-struct on_stop_request {
-    St&  st;
-    auto operator()() const -> void { this->st.request_stop(); }
-};
-template <typename T>
-on_stop_request(T&) -> on_stop_request<T>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/check_type_alias_exist.hpp"
-namespace beman::execution::detail {
-
-#line 17 "include/beman/execution/detail/check_type_alias_exist.hpp"
-template <template <typename> class>
-struct check_type_alias_exist;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/scheduler_t.hpp"
-namespace beman::execution {
-
-#line 16 "include/beman/execution/detail/scheduler_t.hpp"
-export /* --------- */ struct scheduler_t {};
-} // namespace beman::execution
-
-#line 12 "include/beman/execution/detail/get_awaiter.hpp"
-namespace beman::execution::detail {
-template <typename Expr, typename Promise>
-auto get_awaiter(Expr&& expr, Promise& promise) -> decltype(auto) {
-    auto transform{[&]() -> decltype(auto) {
-        if constexpr (requires { promise.await_transform(::std::forward<Expr>(expr)); })
-            return promise.await_transform(::std::forward<Expr>(expr));
-        else
-            return ::std::forward<Expr>(expr);
-    }};
-    if constexpr (requires { operator co_await(transform()); }) {
-
-        static_assert(not requires { transform().operator co_await(); }, "only one operator co_await is allowed");
-        return operator co_await(transform());
-    } else if constexpr (requires { transform().operator co_await(); })
-        return transform().operator co_await();
-    else
-        return transform();
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/sender_decompose.hpp"
-namespace beman::execution::detail {
-struct sender_convert_to_any_t {
-    template <typename T>
-    constexpr operator T() const; // NOLINT(hicpp-explicit-conversions)
-};
-
-template <typename Tag, typename Data, typename Children>
-struct sender_meta {
-    using tag_type      = ::std::remove_cvref_t<Tag>;
-    using data_type     = ::std::remove_cvref_t<Data>;
-    using children_type = ::std::remove_cvref_t<Children>;
-};
-
-template <typename Tag, typename Data, typename Children>
-struct sender_data {
-    using tag_type      = ::std::remove_cvref_t<Tag>;
-    using data_type     = ::std::remove_cvref_t<Data>;
-    using children_type = ::std::remove_cvref_t<Children>;
-
-    tag_type tag;
-    Data&    data;
-    Children children;
-};
-template <typename Tag, typename Data, typename Children>
-sender_data(Tag&&, Data&, Children&&) -> sender_data<Tag, Data, Children>;
-
-template <typename Sender>
-auto get_sender_data(Sender&& sender) {
-#if 0
-
-        auto&& [tag, data, ... children] = sender;
-        return sender_meta<decltype(tag), decltype(data), ::std::tuple<decltype(children)...>>;
-#else
-    using sender_type = ::std::remove_cvref_t<Sender>;
-    static constexpr ::beman::execution::detail::sender_convert_to_any_t at{};
-
-    if constexpr (requires {
-                      sender.template get<0>();
-                      sender.size();
-                  })
-        return [&sender]<::std::size_t... I>(::std::index_sequence<I...>) {
-            return ::beman::execution::detail::sender_data{
-                sender.template get<0>(), sender.template get<1>(), ::std::tie(sender.template get<2 + I>()...)};
-        }(::std::make_index_sequence<::std::decay_t<decltype(sender)>::size() - 2u>{});
-    else if constexpr (requires { sender_type{at, at, at, at, at, at}; }) {
-        auto&& [tag, data, c0, c1, c2, c3] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1, c2, c3)};
-    } else if constexpr (requires { sender_type{at, at, at, at, at}; }) {
-        auto&& [tag, data, c0, c1, c2] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1, c2)};
-    } else if constexpr (requires { sender_type{at, at, at, at}; }) {
-        auto&& [tag, data, c0, c1] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1)};
-    } else if constexpr (requires { sender_type{at, at, at}; }) {
-        auto&& [tag, data, c0] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0)};
-    } else if constexpr (requires { sender_type{at, at}; }) {
-        auto&& [tag, data] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tuple<>{}};
-    } else {
-        return ::beman::execution::detail::sender_meta<void, void, void>{};
-    }
-#endif
-}
-#line 79 "include/beman/execution/detail/sender_decompose.hpp"
-template <typename Sender>
-auto get_sender_meta(Sender&& sender) {
-    using type = decltype(get_sender_data(sender));
-    return sender_meta<typename type::tag_type, typename type::data_type, typename type::children_type>{};
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/suspend_complete.hpp"
-namespace beman::execution::detail {
-template <typename Fun, typename... Args>
-auto suspend_complete(Fun fun, Args&&... args) noexcept {
-    auto f{[&, fun]() noexcept { fun(::std::forward<Args>(args)...); }};
-    struct awaiter {
-        decltype(f) fun;
-
-        static constexpr auto await_ready() noexcept -> bool { return false; }
-        auto                  await_suspend(::std::coroutine_handle<>) noexcept { this->fun(); }
-#if __cpp_lib_unreachable < 202202L
-        [[noreturn]] auto await_resume() noexcept -> void { ::std::terminate(); }
-#else
-        [[noreturn]] auto await_resume() noexcept -> void { ::std::unreachable(); }
-#endif
-    };
-    return awaiter{f};
-}
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/meta_contains.hpp"
-namespace beman::execution::detail::meta {
-template <typename T, typename... S>
-inline constexpr bool contains{(::std::same_as<T, S> || ...)};
-}
-#line 13 "include/beman/execution/detail/decays_to.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/decays_to.hpp"
-template <typename From, typename To>
-concept decays_to = ::std::same_as<::std::decay_t<From>, To>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/intrusive_stack.hpp"
-namespace beman::execution::detail {
-
-template <auto Next>
-class atomic_intrusive_stack;
-
-template <auto Next>
-class intrusive_stack;
-
-#line 20 "include/beman/execution/detail/intrusive_stack.hpp"
-template <class Item, Item* Item::* Next>
-class intrusive_stack<Next> {
-  public:
-#line 24 "include/beman/execution/detail/intrusive_stack.hpp"
-    auto push(Item* item) noexcept -> void { item->*Next = std::exchange(head_, item); }
-
-#line 29 "include/beman/execution/detail/intrusive_stack.hpp"
-    auto pop() noexcept -> Item* {
-        if (head_) {
-            auto item = head_;
-            head_     = std::exchange(item->*Next, nullptr);
-            return item;
-        }
-        return nullptr;
-    }
-#line 39 "include/beman/execution/detail/intrusive_stack.hpp"
-    auto empty() const noexcept -> bool { return !head_; }
-
-  private:
-    friend class atomic_intrusive_stack<Next>;
-    Item* head_{nullptr};
-};
-
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/immovable.hpp"
-namespace beman::execution::detail {
-struct immovable;
-struct virtual_immovable;
-} // namespace beman::execution::detail
-
-struct beman::execution::detail::immovable {
-    constexpr immovable()                          = default;
-    immovable(immovable&&)                         = delete;
-    immovable(const immovable&)                    = delete;
-    ~immovable()                                   = default;
-    auto operator=(immovable&&) -> immovable&      = delete;
-    auto operator=(const immovable&) -> immovable& = delete;
-};
-
-struct beman::execution::detail::virtual_immovable {
-    constexpr virtual_immovable()                                  = default;
-    virtual_immovable(virtual_immovable&&)                         = delete;
-    virtual_immovable(const virtual_immovable&)                    = delete;
-    virtual ~virtual_immovable()                                   = default;
-    auto operator=(virtual_immovable&&) -> virtual_immovable&      = delete;
-    auto operator=(const virtual_immovable&) -> virtual_immovable& = delete;
-};
-
-#line 10 "include/beman/execution/detail/unspecified_promise.hpp"
-namespace beman::execution::detail {
-struct unspecified_promise {
-    auto get_return_object() noexcept -> unspecified_promise;
-    auto initial_suspend() noexcept -> ::std::suspend_never;
-    auto final_suspend() noexcept -> ::std::suspend_never;
-    void unhandled_exception() noexcept;
-    void return_void() noexcept;
-    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<>;
-};
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/await_suspend_result.hpp"
-namespace beman::execution::detail {
-
-#line 20 "include/beman/execution/detail/await_suspend_result.hpp"
-template <typename>
-struct is_coroutine_handle : ::std::false_type {};
-
-#line 27 "include/beman/execution/detail/await_suspend_result.hpp"
-template <typename T>
-struct is_coroutine_handle<::std::coroutine_handle<T>> : ::std::true_type {};
-
-#line 35 "include/beman/execution/detail/await_suspend_result.hpp"
-template <typename T>
-concept await_suspend_result =
-    ::std::same_as<T, void> || ::std::same_as<T, bool> || ::beman::execution::detail::is_coroutine_handle<T>::value;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/valid_specialization.hpp"
-namespace beman::execution::detail {
-template <template <typename...> class T, typename... Args>
-concept valid_specialization = requires { typename T<Args...>; };
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/indirect_meta_apply.hpp"
-namespace beman::execution::detail {
-template <bool>
-struct indirect_meta_apply {
-    template <template <typename...> class T, class... A>
-    using meta_apply = T<A...>;
-};
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/indices_for.hpp"
-namespace beman::execution::detail {
-
-export /* --------- */ template <typename Sender>
-using indices_for = typename ::std::remove_reference_t<Sender>::indices_for;
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/decayed_typeof.hpp"
-namespace beman::execution::detail {
-
-#line 18 "include/beman/execution/detail/decayed_typeof.hpp"
-template <auto&& Tag>
-using decayed_typeof = ::std::decay_t<decltype(Tag)>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/nostopstate.hpp"
-namespace beman::execution {
-export /* --------- */ struct nostopstate_t {
-    explicit nostopstate_t() = default;
-};
-
-export /* --------- */ inline constexpr nostopstate_t nostopstate{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/env.hpp"
-namespace beman::execution::detail {
-template <::beman::execution::detail::queryable Env>
-struct env_base {
-    Env env_;
-};
-
-template <typename E, typename Q>
-concept has_query = requires(const E& e) { e.query(::std::declval<Q>()); };
-
-template <typename Q, typename... E>
-struct find_env;
-template <typename Q, typename E0, typename... E>
-    requires has_query<E0, Q>
-struct find_env<Q, E0, E...> {
-    using type = E0;
-};
-template <typename Q, typename E0, typename... E>
-    requires(not has_query<E0, Q>)
-struct find_env<Q, E0, E...> {
-    using type = typename find_env<Q, E...>::type;
-};
-} // namespace beman::execution::detail
-
-#line 39 "include/beman/execution/detail/env.hpp"
-namespace beman::execution {
-export /* --------- */ template <::beman::execution::detail::queryable... Envs>
-struct env : ::beman::execution::detail::env_base<Envs>... {
-    [[no_unique_address]] ::beman::execution::detail::non_assignable na_{};
-
-    template <typename Q>
-        requires(::beman::execution::detail::has_query<Envs, Q> || ...)
-    constexpr auto query(Q q) const noexcept -> decltype(auto) {
-        using E = typename ::beman::execution::detail::find_env<Q, Envs...>::type;
-        return q(static_cast<const ::beman::execution::detail::env_base<E>&>(*this).env_);
-    }
-};
-
-template <::beman::execution::detail::queryable... Envs>
-env(Envs...) -> env<::std::unwrap_reference_t<Envs>...>;
-} // namespace beman::execution
-
-#line 17 "include/beman/execution/detail/get_allocator.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_allocator_t {
-    template <typename Object>
-        requires(not requires(Object&& object, const get_allocator_t& tag) { ::std::as_const(object).query(tag); })
-    auto
-    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the object requires a const query(get_allocator_t) overload");
-    template <typename Object>
-        requires(
-                    not requires(const Object& object, const get_allocator_t& tag) { object.query(tag); } &&
-                    not requires(Object&& object, const get_allocator_t& tag) { ::std::as_const(object).query(tag); })
-    auto operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the object requires a query(get_allocator_t) overload");
-    template <typename Object>
-        requires(not requires(const Object& object, const get_allocator_t& tag) {
-                    { object.query(tag) } noexcept;
-                })
-    auto
-    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the query(get_allocator_t) overload needs to be noexcept");
-
-    template <typename Object>
-        requires(not requires(const Object& object, const get_allocator_t& tag) {
-                    { object.query(tag) } noexcept -> ::beman::execution::detail::simple_allocator<>;
-                })
-    auto
-    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the query(get_allocator_t) overload needs to be noexcept");
-
-    template <typename Object>
-        requires(requires(const Object& object, const get_allocator_t& tag) {
-            { object.query(tag) } noexcept -> ::beman::execution::detail::simple_allocator<>;
-        })
-    auto operator()(Object&& object) const noexcept {
-        return ::std::as_const(object).query(*this);
-    }
-#line 50 "include/beman/execution/detail/get_allocator.hpp"
-    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
-};
-
-export /* --------- */ inline constexpr get_allocator_t get_allocator{};
-} // namespace beman::execution
-
-#line 15 "include/beman/execution/detail/get_domain.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_domain_t {
-    template <typename Object>
-        requires(not requires(Object&& object, const get_domain_t& tag) {
-                    ::std::forward<Object>(object).query(tag);
-                }) && (not requires(Object&& object, const get_domain_t& tag) { ::std::as_const(object).query(tag); })
-    auto operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("object needs a query(get_domain_t) overload");
-    template <typename Object>
-        requires(not requires(Object&& object, const get_domain_t& tag) { ::std::as_const(object).query(tag); })
-    auto
-    operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("query(get_domain_t) overload needs to be const");
-    template <typename Object>
-        requires(not requires(Object&& object, const get_domain_t& tag) {
-                    { ::std::as_const(object).query(tag) } noexcept;
-                })
-    auto
-    operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("query(get_domain_t) overload needs to be noexcept");
-
-    template <typename Object>
-    constexpr auto operator()(Object&& object) const noexcept {
-        return ::std::as_const(object).query(*this);
-    }
-    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
-};
-
-export /* --------- */ inline constexpr get_domain_t get_domain{};
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/get_scheduler.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_scheduler_t : ::beman::execution::forwarding_query_t {
-    template <typename Env>
-        requires requires(const get_scheduler_t& self, Env&& env) { ::std::as_const(env).query(self); }
-    auto operator()(Env&& env) const noexcept {
-        static_assert(noexcept(::std::as_const(env).query(*this)));
-
-#line 23 "include/beman/execution/detail/get_scheduler.hpp"
-        return ::std::as_const(env).query(*this);
-    }
-};
-
-export /* --------- */ inline constexpr get_scheduler_t get_scheduler{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/operation_state.hpp"
-namespace beman::execution {
-export /* --------- */ struct operation_state_t {};
-
-export /* --------- */ template <typename State>
-concept operation_state =
-    ::std::derived_from<typename State::operation_state_concept, ::beman::execution::operation_state_t> &&
-    ::std::is_object_v<State> && requires(State& state) {
-        { ::beman::execution::start(state) } noexcept;
-    };
-} // namespace beman::execution
-
-#line 16 "include/beman/execution/detail/valid_completion_for.hpp"
-namespace beman::execution::detail {
-template <typename, typename>
-struct valid_completion_for_aux;
-
-template <typename Rcvr, typename Tag, typename... Args>
-struct valid_completion_for_aux<Rcvr, Tag (*)(Args...)> {
-    static auto test(Tag (*)(Args...)) -> void
-        requires ::beman::execution::detail::callable<Tag, ::std::remove_cvref_t<Rcvr>, Args...>
-    {}
-};
-
-export /* --------- */ template <typename Signature, typename Rcvr>
-concept valid_completion_for = requires(Signature* signature) {
-#if 1
-    valid_completion_for_aux<Rcvr, Signature*>::test(signature);
-#else
-#line 33 "include/beman/execution/detail/valid_completion_for.hpp"
-    []<typename Tag, typename... Args>(Tag (*)(Args...))
-        requires ::beman::execution::detail::callable<Tag, ::std::remove_cvref_t<Rcvr>, Args...>
-    {}(signature);
-#endif
-};
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/completion_signature.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct is_set_error : ::std::false_type {};
-template <typename Error>
-struct is_set_error<::beman::execution::set_error_t(Error)> : ::std::true_type {};
-
-template <typename Fun>
-using is_set_stopped = ::std::is_same<Fun, ::beman::execution::set_stopped_t()>;
-
-template <typename>
-struct is_set_value : ::std::false_type {};
-template <typename... Args>
-struct is_set_value<::beman::execution::set_value_t(Args...)> : ::std::true_type {};
-
-#line 42 "include/beman/execution/detail/completion_signature.hpp"
-template <typename Fun>
-concept completion_signature =
-    ::beman::execution::detail::is_set_error<Fun>::value || ::beman::execution::detail::is_set_stopped<Fun>::value ||
-    ::beman::execution::detail::is_set_value<Fun>::value;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/prop.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct prop_like;
-}
-#line 19 "include/beman/execution/detail/prop.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Query, typename Value>
-struct prop;
-
-template <typename Query, typename Value>
-prop(Query, Value, ::beman::execution::detail::non_assignable = {}) -> prop<Query, ::std::unwrap_reference_t<Value>>;
-} // namespace beman::execution
-
-template <typename V>
-struct beman::execution::detail::prop_like {
-    V    value;
-    auto query(auto) const noexcept -> const V& { return this->value; }
-};
-
-template <typename Query, typename Value>
-struct beman::execution::prop {
-    static_assert(::beman::execution::detail::callable<Query, ::beman::execution::detail::prop_like<Value>>);
-
-    [[no_unique_address]] Query                                      query_{};
-    [[no_unique_address]] Value                                      value_{};
-    [[no_unique_address]] ::beman::execution::detail::non_assignable non_assignable_{};
-
-#line 46 "include/beman/execution/detail/prop.hpp"
-    constexpr auto query(Query) const noexcept -> const Value& { return this->value_; }
-};
-
-#line 13 "include/beman/execution/detail/stoppable_token.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Token>
-concept stoppable_token = requires(const Token& token) {
-    typename ::beman::execution::detail::check_type_alias_exist<Token::template callback_type>;
-    { token.stop_requested() } noexcept -> ::std::same_as<bool>;
-    { token.stop_possible() } noexcept -> ::std::same_as<bool>;
-    { Token(token) } noexcept;
-} && ::std::copyable<Token> && ::std::equality_comparable<Token> && ::std::swappable<Token>;
-} // namespace beman::execution
-
-#line 15 "include/beman/execution/detail/completion_tag.hpp"
-namespace beman::execution::detail {
-
-#line 21 "include/beman/execution/detail/completion_tag.hpp"
-template <typename Tag>
-concept completion_tag =
-    ::std::same_as<Tag, ::beman::execution::set_error_t> || ::std::same_as<Tag, ::beman::execution::set_stopped_t> ||
-    ::std::same_as<Tag, ::beman::execution::set_value_t>;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/await_result_type.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/await_result_type.hpp"
-export /* --------- */ template <typename T, typename Promise>
-using await_result_type =
-    decltype(::beman::execution::detail::get_awaiter(::std::declval<T>(), ::std::declval<Promise&>()).await_resume());
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/fwd_env.hpp"
-namespace beman::execution::detail {
-
-#line 22 "include/beman/execution/detail/fwd_env.hpp"
-export /* --------- */ template <typename Env>
-class fwd_env {
-  private:
-    Env env;
-
-  public:
-    explicit fwd_env(Env&& e) : env(::std::forward<Env>(e)) {}
-
-    template <typename Query, typename... Args>
-        requires(!::beman::execution::forwarding_query(::std::remove_cvref_t<Query>()))
-    constexpr auto query(Query&& q,
-                         Args&&... args) const = BEMAN_EXECUTION_DELETE("the used query is not forwardable");
-
-    template <typename Query, typename... Args>
-        requires(::beman::execution::forwarding_query(::std::remove_cvref_t<Query>())) &&
-                requires(const Env& e, Query&& q, Args&&... args) { e.query(q, ::std::forward<Args>(args)...); }
-    constexpr auto query(Query&& q, Args&&... args) const
-        noexcept(noexcept(env.query(q, ::std::forward<Args>(args)...))) {
-        return env.query(q, ::std::forward<Args>(args)...);
-    }
-};
-template <typename Env>
-fwd_env(Env&&) -> fwd_env<Env>;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/tag_of_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Sender>
-using tag_of_t = typename decltype(::beman::execution::detail::get_sender_meta(::std::declval<Sender&&>()))::tag_type;
-}
-#line 13 "include/beman/execution/detail/meta_combine.hpp"
-namespace beman::execution::detail::meta::detail {
-template <typename...>
-struct combine;
-
-template <template <typename...> class L0, typename... T0>
-struct combine<L0<T0...>> {
-    using type = L0<T0...>;
-};
-template <template <typename...> class L0,
-          typename... T0,
-          template <typename...> class L1,
-          typename... T1,
-          typename... L>
-struct combine<L0<T0...>, L1<T1...>, L...> {
-    using type = typename combine<L0<T0..., T1...>, L...>::type;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <typename... L>
-using combine = typename ::beman::execution::detail::meta::detail::combine<L...>::type;
-}
-#line 15 "include/beman/execution/detail/meta_unique.hpp"
-namespace beman::execution::detail::meta::detail {
-template <typename, typename>
-struct make_unique;
-template <typename>
-struct unique;
-
-template <template <typename...> class List, typename... R>
-struct make_unique<List<R...>, List<>> {
-    using type = List<R...>;
-};
-
-template <template <typename...> class List, typename... R, typename H, typename... T>
-struct make_unique<List<R...>, List<H, T...>> {
-    using type = typename ::beman::execution::detail::meta::detail::make_unique<
-        ::std::conditional_t<::beman::execution::detail::meta::contains<H, R...>, List<R...>, List<R..., H>>,
-        List<T...>>::type;
-};
-
-template <template <typename...> class List, typename... T>
-struct unique<List<T...>> {
-    using type = typename ::beman::execution::detail::meta::detail::make_unique<List<>, List<T...>>::type;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <typename T>
-using unique = typename ::beman::execution::detail::meta::detail::unique<T>::type;
-}
-#line 13 "include/beman/execution/detail/meta_filter.hpp"
-namespace beman::execution::detail::meta::detail {
-template <template <typename> class, typename>
-struct filter;
-
-template <template <typename, typename> class, typename, typename>
-struct filter_tag;
-
-template <template <typename> class Predicate, template <typename...> class List>
-struct filter<Predicate, List<>> {
-    using type = List<>;
-};
-
-template <template <typename, typename> class Predicate, typename Tag, template <typename...> class List>
-struct filter_tag<Predicate, Tag, List<>> {
-    using type = List<>;
-};
-
-template <template <typename> class Predicate, template <typename...> class List, typename H, typename... T>
-struct filter<Predicate, List<H, T...>> {
-    using tail = typename beman::execution::detail::meta::detail::filter<Predicate, List<T...>>::type;
-    using type = ::std::conditional_t<Predicate<H>::value, ::beman::execution::detail::meta::prepend<H, tail>, tail>;
-};
-
-template <template <typename, typename> class Predicate,
-          typename Tag,
-          template <typename...> class List,
-          typename H,
-          typename... T>
-struct filter_tag<Predicate, Tag, List<H, T...>> {
-    using tail = typename beman::execution::detail::meta::detail::filter_tag<Predicate, Tag, List<T...>>::type;
-    using type =
-        ::std::conditional_t<Predicate<Tag, H>::value, ::beman::execution::detail::meta::prepend<H, tail>, tail>;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <template <typename> class Predicate, typename List>
-using filter = typename ::beman::execution::detail::meta::detail::filter<Predicate, List>::type;
-
-template <template <typename, typename> class Predicate, typename Tag, typename List>
-using filter_tag = typename ::beman::execution::detail::meta::detail::filter_tag<Predicate, Tag, List>::type;
-} // namespace beman::execution::detail::meta
-
-#line 12 "include/beman/execution/detail/meta_transform.hpp"
-namespace beman::execution::detail::meta::detail {
-template <template <typename> class Transform, typename List>
-struct transform;
-
-template <template <typename> class Transform, template <typename... T> class List, typename... T>
-struct transform<Transform, List<T...>> {
-    using type = List<Transform<T>...>;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <template <typename> class Transform, typename List>
-using transform = typename ::beman::execution::detail::meta::detail::transform<Transform, List>::type;
-}
-#line 12 "include/beman/execution/detail/as_tuple.hpp"
-namespace beman::execution::detail {
-
-#line 17 "include/beman/execution/detail/as_tuple.hpp"
-template <typename T>
-struct as_tuple;
-
-#line 23 "include/beman/execution/detail/as_tuple.hpp"
-template <typename Rc, typename... A>
-struct as_tuple<Rc(A...)> {
-    using type = ::beman::execution::detail::decayed_tuple<Rc, A...>;
-};
-
-template <typename T>
-using as_tuple_t = typename ::beman::execution::detail::as_tuple<T>::type;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-namespace beman::execution::detail {
-
-template <auto Next>
-class atomic_intrusive_stack;
-
-#line 35 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-template <class Item, Item* Item::* Next>
-class atomic_intrusive_stack<Next> {
-  public:
-    atomic_intrusive_stack() = default;
-    ~atomic_intrusive_stack() { assert(!head_ || head_ == this); }
-    atomic_intrusive_stack(const atomic_intrusive_stack&)                        = delete;
-    auto operator=(const atomic_intrusive_stack&) -> atomic_intrusive_stack&     = delete;
-    atomic_intrusive_stack(atomic_intrusive_stack&&) noexcept                    = delete;
-    auto operator=(atomic_intrusive_stack&&) noexcept -> atomic_intrusive_stack& = delete;
-
-#line 51 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-    auto try_push(Item* item) noexcept -> std::optional<Item*> {
-        void* ptr = head_.load();
-        if (ptr == this) {
-            return std::nullopt;
-        }
-        item->*Next = static_cast<Item*>(ptr);
-        while (!head_.compare_exchange_weak(ptr, item)) {
-            if (ptr == this) {
-                return std::nullopt;
-            }
-            item->*Next = static_cast<Item*>(ptr);
-        }
-        return static_cast<Item*>(ptr);
-    }
-#line 67 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-    auto empty_and_not_shutdown() const noexcept -> bool { return head_.load() == nullptr; }
-
-#line 72 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-    auto pop_all_and_shutdown() noexcept -> ::beman::execution::detail::intrusive_stack<Next> {
-        auto  stack = ::beman::execution::detail::intrusive_stack<Next>{};
-        void* ptr   = head_.exchange(this);
-        if (ptr == this) {
-            return stack;
-        }
-        auto item   = static_cast<Item*>(ptr);
-        stack.head_ = item;
-        return stack;
-    }
-#line 83 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-  private:
-    ::std::atomic<void*> head_{nullptr};
-};
-
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/inplace_stop_source.hpp"
-namespace beman::execution {
-export /* --------- */ class inplace_stop_token;
-export /* --------- */ class inplace_stop_source;
-export /* --------- */ template <typename CallbackFun>
-class inplace_stop_callback;
-export /* --------- */ template <typename CallbackFun>
-inplace_stop_callback(::beman::execution::inplace_stop_token, CallbackFun) -> inplace_stop_callback<CallbackFun>;
-} // namespace beman::execution
-
-#line 28 "include/beman/execution/detail/inplace_stop_source.hpp"
-class beman::execution::inplace_stop_token {
-  public:
-    template <typename CallbackFun>
-    using callback_type = ::beman::execution::inplace_stop_callback<CallbackFun>;
-
-    inplace_stop_token() = default;
-
-    constexpr auto stop_requested() const noexcept -> bool;
-    constexpr auto stop_possible() const noexcept -> bool;
-    auto           operator==(const inplace_stop_token&) const -> bool = default;
-
-    auto swap(inplace_stop_token&) noexcept -> void;
-
-  private:
-    friend class ::beman::execution::inplace_stop_source;
-    template <typename CallbackFun>
-    friend class ::beman::execution::inplace_stop_callback;
-    explicit inplace_stop_token(::beman::execution::inplace_stop_source* src) : source(src) {}
-
-    ::beman::execution::inplace_stop_source* source{};
-};
-
-#line 52 "include/beman/execution/detail/inplace_stop_source.hpp"
-class beman::execution::inplace_stop_source {
-    struct callback_base : public ::beman::execution::detail::virtual_immovable {
-        callback_base* next{};
-        virtual auto   call() -> void = 0;
-    };
-
-  public:
-    auto                  stop_requested() const noexcept -> bool;
-    static constexpr auto stop_possible() noexcept -> bool;
-    auto                  get_token() const -> ::beman::execution::inplace_stop_token;
-
-    auto request_stop() -> bool;
-
-  private:
-    template <typename CallbackFun>
-    friend class ::beman::execution::inplace_stop_callback;
-    ::std::atomic<bool>           stopped{};
-    ::std::atomic<callback_base*> running{};
-    ::std::thread::id             id{};
-    ::std::mutex                  lock;
-    callback_base*                callbacks{};
-
-    auto add(callback_base* cb) -> void;
-    auto deregister(callback_base* cb) -> void;
-};
-
-#line 80 "include/beman/execution/detail/inplace_stop_source.hpp"
-template <typename CallbackFun>
-class beman::execution::inplace_stop_callback final : public ::beman::execution::inplace_stop_source::callback_base {
-  public:
-    using callback_type = CallbackFun;
-
-    template <typename Init>
-    inplace_stop_callback(::beman::execution::inplace_stop_token, Init&&);
-    inplace_stop_callback(const inplace_stop_callback&) = delete;
-    inplace_stop_callback(inplace_stop_callback&&)      = delete;
-    ~inplace_stop_callback() override {
-        if (this->source) {
-            this->source->deregister(this);
-        }
-    }
-    auto operator=(const inplace_stop_callback&) -> inplace_stop_callback& = delete;
-    auto operator=(inplace_stop_callback&&) -> inplace_stop_callback&      = delete;
-
-  private:
-    auto call() -> void override;
-
-    CallbackFun                              fun;
-    ::beman::execution::inplace_stop_source* source;
-};
-
-#line 106 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline constexpr auto beman::execution::inplace_stop_token::stop_requested() const noexcept -> bool {
-    return this->source && this->source->stop_requested();
-}
-#line 110 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline constexpr auto beman::execution::inplace_stop_token::stop_possible() const noexcept -> bool {
-    return this->source;
-}
-#line 114 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_token::swap(inplace_stop_token& other) noexcept -> void {
-    ::std::swap(this->source, other.source);
-}
-#line 118 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_source::stop_requested() const noexcept -> bool { return this->stopped; }
-
-inline constexpr auto beman::execution::inplace_stop_source::stop_possible() noexcept -> bool { return true; }
-
-inline auto beman::execution::inplace_stop_source::get_token() const -> ::beman::execution::inplace_stop_token {
-    return ::beman::execution::inplace_stop_token(const_cast<::beman::execution::inplace_stop_source*>(this));
-}
-#line 126 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_source::request_stop() -> bool {
-    using relock = ::std::unique_ptr<::std::unique_lock<::std::mutex>, decltype([](auto p) { p->lock(); })>;
-    if (false == this->stopped.exchange(true)) {
-        ::std::unique_lock guard(this->lock);
-        for (auto it = this->callbacks; it != nullptr; it = this->callbacks) {
-            this->running   = it;
-            this->id        = ::std::this_thread::get_id();
-            this->callbacks = it->next;
-            {
-                relock r(&guard);
-                guard.unlock();
-                it->call();
-            }
-            this->running = nullptr;
-        }
-        return true;
-    }
-    return false;
-}
-#line 146 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_source::add(callback_base* cb) -> void {
-    if (this->stopped) {
-        cb->call();
-    } else {
-        ::std::lock_guard guard(this->lock);
-        cb->next = ::std::exchange(this->callbacks, cb);
-    }
-}
-#line 155 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_source::deregister(callback_base* cb) -> void {
-    ::std::unique_lock guard(this->lock);
-    if (this->running == cb) {
-        if (this->id == ::std::this_thread::get_id()) {
-            return;
-        }
-        guard.unlock();
-        while (this->running == cb) {
-        }
-        return;
-    }
-#line 167 "include/beman/execution/detail/inplace_stop_source.hpp"
-    for (callback_base** it{&this->callbacks}; *it; it = &(*it)->next) {
-        if (*it == cb) {
-            *it = cb->next;
-            break;
-        }
-    }
-}
-#line 175 "include/beman/execution/detail/inplace_stop_source.hpp"
-template <typename CallbackFun>
-template <typename Init>
-inline beman::execution::inplace_stop_callback<CallbackFun>::inplace_stop_callback(
-    ::beman::execution::inplace_stop_token token, Init&& init)
-    : fun(::std::forward<Init>(init)), source(token.source) {
-    if (this->source) {
-        this->source->add(this);
-    }
-}
-#line 185 "include/beman/execution/detail/inplace_stop_source.hpp"
-template <typename CallbackFun>
-inline auto beman::execution::inplace_stop_callback<CallbackFun>::call() -> void {
-    this->fun();
-}
-#line 13 "include/beman/execution/detail/decayed_type_list.hpp"
-namespace beman::execution::detail {
-template <class... Args>
-using decayed_type_list = ::beman::execution::detail::type_list<::std::decay_t<Args>...>;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/class_type.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/class_type.hpp"
-template <typename Tp>
-concept class_type = ::beman::execution::detail::decays_to<Tp, Tp> && ::std::is_class_v<Tp>;
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/nothrow_callable.hpp"
-namespace beman::execution::detail {
-template <typename Fun, typename... Args>
-concept nothrow_callable = ::beman::execution::detail::callable<Fun, Args...> && requires(Fun&& fun, Args&&... args) {
-    { ::std::forward<Fun>(fun)(::std::forward<Args>(args)...) } noexcept;
-};
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/counting_scope_base.hpp"
-namespace beman::execution::detail {
-class counting_scope_base;
-}
-#line 22 "include/beman/execution/detail/counting_scope_base.hpp"
-class beman::execution::detail::counting_scope_base : ::beman::execution::detail::immovable {
-  public:
-    counting_scope_base()                      = default;
-    counting_scope_base(counting_scope_base&&) = delete;
-    ~counting_scope_base();
-
-    static constexpr ::std::size_t max_associations{8194u};
-
-    auto close() noexcept -> void;
-
-    struct node {
-        virtual auto complete() noexcept -> void        = 0;
-        virtual auto complete_inline() noexcept -> void = 0;
-        node*        next{};
-    };
-    auto start_node(node*) -> void;
-
-  protected:
-    class token {
-      public:
-        auto try_associate() const noexcept -> bool { return this->scope->try_associate(); }
-        auto disassociate() const noexcept -> void { this->scope->disassociate(); }
-
-      protected:
-        explicit token(::beman::execution::detail::counting_scope_base* s) : scope(s) {}
-        ::beman::execution::detail::counting_scope_base* scope;
-    };
-
-  private:
-    enum class state_t : unsigned char {
-        unused,
-        open,
-        open_and_joining,
-        closed,
-        closed_and_joining,
-        unused_and_closed,
-        joined
-    };
-
-    auto try_associate() noexcept -> bool;
-    auto disassociate() noexcept -> void;
-    auto complete() noexcept -> void;
-    auto add_node(node* n, ::std::lock_guard<::std::mutex>&) noexcept -> void;
-
-    ::std::mutex mutex;
-
-    ::std::size_t count{};
-    state_t       state{state_t::unused};
-    node*         head{};
-};
-
-#line 75 "include/beman/execution/detail/counting_scope_base.hpp"
-inline beman::execution::detail::counting_scope_base::~counting_scope_base() {
-    ::std::lock_guard kerberos(this->mutex);
-    switch (this->state) {
-    default:
-        ::std::terminate();
-    case state_t::unused:
-    case state_t::unused_and_closed:
-    case state_t::joined:
-        break;
-    }
-}
-#line 87 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::close() noexcept -> void {
-    switch (this->state) {
-    default:
-        break;
-    case state_t::unused:
-        this->state = state_t::unused_and_closed;
-        break;
-    case state_t::open:
-        this->state = state_t::closed;
-        break;
-    case state_t::open_and_joining:
-        this->state = state_t::closed_and_joining;
-        break;
-    }
-}
-#line 103 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::add_node(node* n, ::std::lock_guard<::std::mutex>&) noexcept
-    -> void {
-    n->next = std::exchange(this->head, n);
-}
-#line 108 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::try_associate() noexcept -> bool {
-    ::std::lock_guard lock(this->mutex);
-    switch (this->state) {
-    default:
-        return false;
-    case state_t::unused:
-        this->state = state_t::open;
-        [[fallthrough]];
-    case state_t::open:
-    case state_t::open_and_joining:
-        ++this->count;
-        return true;
-    }
-}
-#line 123 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::disassociate() noexcept -> void {
-    {
-        ::std::lock_guard lock(this->mutex);
-        if (0u < --this->count)
-            return;
-        this->state = state_t::joined;
-    }
-    this->complete();
-}
-#line 133 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::complete() noexcept -> void {
-    node* current{[this] {
-        ::std::lock_guard lock(this->mutex);
-        return ::std::exchange(this->head, nullptr);
-    }()};
-    while (current) {
-        ::std::exchange(current, current->next)->complete();
-    }
-}
-#line 143 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::start_node(node* n) -> void {
-    ::std::lock_guard kerberos(this->mutex);
-    switch (this->state) {
-    case ::beman::execution::detail::counting_scope_base::state_t::unused:
-    case ::beman::execution::detail::counting_scope_base::state_t::unused_and_closed:
-    case ::beman::execution::detail::counting_scope_base::state_t::joined:
-        this->state = ::beman::execution::detail::counting_scope_base::state_t::joined;
-        n->complete_inline();
-        return;
-    case ::beman::execution::detail::counting_scope_base::state_t::open:
-        this->state = ::beman::execution::detail::counting_scope_base::state_t::open_and_joining;
-        break;
-    case ::beman::execution::detail::counting_scope_base::state_t::open_and_joining:
-        break;
-    case ::beman::execution::detail::counting_scope_base::state_t::closed:
-        this->state = ::beman::execution::detail::counting_scope_base::state_t::closed_and_joining;
-        break;
-    case ::beman::execution::detail::counting_scope_base::state_t::closed_and_joining:
-        break;
-    }
-    this->add_node(n, kerberos);
-}
-#line 13 "include/beman/execution/detail/is_awaiter.hpp"
-namespace beman::execution::detail {
-template <typename Awaiter, typename Promise>
-concept is_awaiter = requires(Awaiter& awaiter, ::std::coroutine_handle<Promise> handle) {
-    awaiter.await_ready() ? 1 : 0;
-    { awaiter.await_suspend(handle) } -> ::beman::execution::detail::await_suspend_result;
-    awaiter.await_resume();
-};
-} // namespace beman::execution::detail
-
-#line 18 "include/beman/execution/detail/stop_source.hpp"
-namespace beman::execution {
-export /* --------- */ class stop_token;
-export /* --------- */ class stop_source;
-export /* --------- */ template <typename CallbackFun>
-class stop_callback;
-export /* --------- */ template <typename CallbackFun>
-stop_callback(::beman::execution::stop_token, CallbackFun) -> stop_callback<CallbackFun>;
-} // namespace beman::execution
-
-namespace beman::execution::detail {
-struct stop_state;
-struct stop_callback_base;
-} // namespace beman::execution::detail
-
-#line 33 "include/beman/execution/detail/stop_source.hpp"
-struct beman::execution::detail::stop_state {
-    ::std::atomic<bool>                           stop_requested{};
-    ::std::atomic<::std::size_t>                  sources{};
-    ::std::mutex                                  lock{};
-    beman::execution::detail::stop_callback_base* callbacks{};
-    ::std::atomic<bool>                           executing{};
-
-    auto stop_possible() const -> bool { return this->sources != 0 || this->stop_requested; }
-};
-
-#line 45 "include/beman/execution/detail/stop_source.hpp"
-struct beman::execution::detail::stop_callback_base {
-  private:
-    using stop_state = ::beman::execution::detail::stop_state;
-    ::std::shared_ptr<stop_state> state;
-
-    virtual auto do_call() -> void = 0;
-
-  protected:
-    explicit stop_callback_base(const ::beman::execution::stop_token&);
-    ~stop_callback_base();
-
-  public:
-    stop_callback_base(stop_callback_base&&)                         = delete;
-    stop_callback_base(const stop_callback_base&)                    = delete;
-    auto operator=(stop_callback_base&&) -> stop_callback_base&      = delete;
-    auto operator=(const stop_callback_base&) -> stop_callback_base& = delete;
-    auto call() -> void;
-    auto setup() -> void;
-    auto deregister() -> void;
-
-    stop_callback_base* next{};
-    ::std::thread::id   id{};
-};
-
-#line 71 "include/beman/execution/detail/stop_source.hpp"
-class beman::execution::stop_source {
-  private:
-    using stop_state = ::beman::execution::detail::stop_state;
-
-    ::std::shared_ptr<stop_state> state{::std::make_shared<stop_state>()};
-
-  public:
-    using stop_token = ::beman::execution::stop_token;
-
-    stop_source();
-    explicit stop_source(::beman::execution::nostopstate_t) noexcept;
-    stop_source(const stop_source&);
-    stop_source(stop_source&&) = default;
-    auto operator=(const stop_source&) -> stop_source&;
-    auto operator=(stop_source&&) -> stop_source& = default;
-    ~stop_source();
-
-    auto swap(stop_source&) noexcept -> void;
-    auto get_token() const -> stop_token;
-    auto stop_requested() const noexcept -> bool;
-    auto stop_possible() const noexcept -> bool;
-    auto request_stop() noexcept -> bool;
-};
-
-#line 97 "include/beman/execution/detail/stop_source.hpp"
-class beman::execution::stop_token {
-  private:
-    friend ::beman::execution::stop_source;
-    friend ::beman::execution::detail::stop_callback_base;
-    ::std::shared_ptr<::beman::execution::detail::stop_state> state;
-
-    explicit stop_token(::std::shared_ptr<::beman::execution::detail::stop_state>);
-
-  public:
-    template <typename Fun>
-    using callback_type = ::beman::execution::stop_callback<Fun>;
-
-    stop_token() = default;
-
-    auto               swap(stop_token& other) noexcept -> void;
-    [[nodiscard]] auto stop_requested() const noexcept -> bool;
-    [[nodiscard]] auto stop_possible() const noexcept -> bool;
-
-    [[nodiscard]] auto operator==(const stop_token&) const noexcept -> bool = default;
-};
-
-#line 120 "include/beman/execution/detail/stop_source.hpp"
-template <typename CallbackFun>
-class beman::execution::stop_callback final : private CallbackFun, beman::execution::detail::stop_callback_base {
-  private:
-    static_assert(::std::invocable<CallbackFun>);
-    static_assert(::std::destructible<CallbackFun>);
-
-    using stop_token = ::beman::execution::stop_token;
-
-    auto do_call() -> void override { (*this)(); }
-
-  public:
-    using callback_type = CallbackFun;
-
-    template <typename Initializer>
-    stop_callback(const stop_token& token,
-                  Initializer&&     init) noexcept(::std::is_nothrow_constructible_v<CallbackFun, Initializer>)
-        requires(::std::constructible_from<CallbackFun, Initializer>)
-        : CallbackFun(::std::forward<Initializer>(init)), stop_callback_base(token) {
-        this->setup();
-    }
-    template <typename Initializer>
-    stop_callback(stop_token&&  token,
-                  Initializer&& init) noexcept(::std::is_nothrow_constructible_v<CallbackFun, Initializer>)
-        requires(::std::is_constructible_v<CallbackFun, Initializer>)
-        : CallbackFun(::std::forward<Initializer>(init)), stop_callback_base(::std::move(token)) {
-        this->setup();
-    }
-    stop_callback(const stop_callback&) = delete;
-    stop_callback(stop_callback&&)      = delete;
-    ~stop_callback() { this->deregister(); }
-    auto operator=(stop_callback&&) -> stop_callback&      = delete;
-    auto operator=(const stop_callback&) -> stop_callback& = delete;
-};
-
-#line 156 "include/beman/execution/detail/stop_source.hpp"
-inline beman::execution::detail::stop_callback_base::stop_callback_base(const ::beman::execution::stop_token& token)
-    : state(token.state) {}
-
-inline beman::execution::detail::stop_callback_base::~stop_callback_base() {}
-
-inline auto beman::execution::detail::stop_callback_base::setup() -> void {
-    if (this->state) {
-        {
-            ::std::lock_guard guard(this->state->lock);
-            if (!this->state->stop_requested) {
-                this->next = ::std::exchange(this->state->callbacks, this);
-                return;
-            }
-        }
-        this->call();
-    }
-}
-#line 174 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::detail::stop_callback_base::deregister() -> void {
-    if (this->state) {
-        ::std::unique_lock guard(this->state->lock);
-        if (this->state->executing && this->id != ::std::this_thread::get_id()) {
-            using lock_again = decltype([](auto p) { p->lock(); });
-            ::std::unique_ptr<decltype(guard), lock_again> relock(&guard);
-            relock->unlock();
-            while (this->state->executing)
-                ;
-        }
-        for (auto n = &this->state->callbacks; *n; n = &this->next) {
-            if (*n == this) {
-                *n = this->next;
-                break;
-            }
-        }
-    }
-}
-#line 193 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::detail::stop_callback_base::call() -> void { this->do_call(); }
-
-inline beman::execution::stop_token::stop_token(::std::shared_ptr<::beman::execution::detail::stop_state> st)
-    : state(::std::move(st)) {}
-
-inline auto beman::execution::stop_token::swap(stop_token& other) noexcept -> void { this->state.swap(other.state); }
-
-inline auto beman::execution::stop_token::stop_requested() const noexcept -> bool {
-    return this->state && this->state->stop_requested;
-}
-#line 204 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::stop_token::stop_possible() const noexcept -> bool {
-    return this->state && this->state->stop_possible();
-}
-#line 210 "include/beman/execution/detail/stop_source.hpp"
-inline beman::execution::stop_source::stop_source() { ++this->state->sources; }
-
-inline beman::execution::stop_source::stop_source(::beman::execution::nostopstate_t) noexcept : state() {}
-
-inline beman::execution::stop_source::stop_source(const stop_source& other) : state(other.state) {
-    ++this->state->sources;
-}
-#line 218 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::stop_source::operator=(const stop_source& other) -> stop_source& {
-    stop_source(other).swap(*this);
-    return *this;
-}
-#line 223 "include/beman/execution/detail/stop_source.hpp"
-inline beman::execution::stop_source::~stop_source() { this->state && --this->state->sources; }
-
-inline auto beman::execution::stop_source::swap(::beman::execution::stop_source& other) noexcept -> void {
-    this->state.swap(other.state);
-}
-#line 229 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::stop_source::get_token() const -> stop_token { return stop_token{this->state}; }
-
-inline auto beman::execution::stop_source::stop_requested() const noexcept -> bool {
-    return this->state && this->state->stop_requested;
-}
-#line 235 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::stop_source::stop_possible() const noexcept -> bool { return true && this->state; }
-
-inline auto beman::execution::stop_source::request_stop() noexcept -> bool {
-    using release    = decltype([](auto p) { *p = false; });
-    using lock_again = decltype([](auto p) { p->lock(); });
-
-    if (this->state && not this->state->stop_requested.exchange(true)) {
-        ::std::unique_lock guard(this->state->lock);
-        while (this->state->callbacks) {
-            auto front = ::std::exchange(this->state->callbacks, this->state->callbacks->next);
-            ::std::unique_ptr<::std::atomic<bool>, release> reset(&state->executing);
-            *reset    = true;
-            front->id = ::std::this_thread::get_id();
-            ::std::unique_ptr<decltype(guard), lock_again> relock(&guard);
-            relock->unlock();
-            front->call();
-        }
-        return true;
-    }
-    return false;
-}
-#line 16 "include/beman/execution/detail/get_stop_token.hpp"
-namespace beman::execution::detail {
-template <typename Token>
-concept decayed_stoppable_token = ::beman::execution::stoppable_token<::std::decay_t<Token>>;
-}
-namespace beman::execution {
-export /* --------- */ struct get_stop_token_t {
-    template <typename Object>
-        requires requires(Object&& object, const get_stop_token_t& tag) {
-            { ::std::as_const(object).query(tag) } noexcept -> ::beman::execution::detail::decayed_stoppable_token;
-        }
-    auto operator()(Object&& object) const noexcept {
-        return ::std::as_const(object).query(*this);
-    }
-#line 30 "include/beman/execution/detail/get_stop_token.hpp"
-    template <typename Object>
-    auto operator()(Object&&) const noexcept -> ::beman::execution::never_stop_token {
-        return {};
-    }
-#line 35 "include/beman/execution/detail/get_stop_token.hpp"
-    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
-};
-
-export /* --------- */ inline constexpr get_stop_token_t get_stop_token{};
-} // namespace beman::execution
-
-#line 15 "include/beman/execution/detail/get_env.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_env_t {
-    template <typename Object>
-        requires(not requires(::std::add_const_t<::std::remove_cvref_t<Object>>& object) { object.get_env(); } ||
-                 ::beman::execution::detail::queryable<
-                     std::remove_cvref_t<decltype(::std::declval<const ::std::remove_cvref_t<Object>&>().get_env())>>)
-    auto operator()(Object&& object) const noexcept -> decltype(auto) {
-        ::std::add_const_t<::std::remove_cvref_t<Object>>& obj{object};
-        if constexpr (requires { obj.get_env(); }) {
-            static_assert(noexcept(obj.get_env()), "get_env requires the expression to be noexcept");
-            static_assert(::beman::execution::detail::queryable<std::remove_cvref_t<decltype(obj.get_env())>>,
-                          "get_env requires the result type to be destructible");
-            return obj.get_env();
-        } else {
-            return ::beman::execution::env<>{};
-        }
-    }
-};
-
-export /* --------- */ inline constexpr get_env_t get_env{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/completion_signatures.hpp"
-namespace beman::execution {
-
-#line 24 "include/beman/execution/detail/completion_signatures.hpp"
-export /* --------- */ template <::beman::execution::detail::completion_signature...>
-struct completion_signatures {};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/is_awaitable.hpp"
-namespace beman::execution::detail {
-template <typename T, typename Promise>
-concept is_awaitable = requires(Promise& promise) {
-    {
-        ::beman::execution::detail::get_awaiter(::std::declval<T>(), promise)
-    } -> ::beman::execution::detail::is_awaiter<Promise>;
-};
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/emplace_from.hpp"
-namespace beman::execution::detail {
-
-#line 21 "include/beman/execution/detail/emplace_from.hpp"
-template <typename Fun>
-struct emplace_from {
-    using type = ::beman::execution::detail::call_result_t<Fun>;
-    Fun fun;
-
-    explicit constexpr operator type() && noexcept(::beman::execution::detail::nothrow_callable<Fun>) {
-        return ::std::move(fun)();
-    }
-};
-template <typename Fun>
-emplace_from(Fun&&) -> emplace_from<::std::remove_cvref_t<Fun>>;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/variant_or_empty.hpp"
-namespace beman::execution::detail {
-struct empty_variant {
-    empty_variant() = delete;
-};
-
-template <typename... T>
-struct variant_or_empty_helper;
-
-template <>
-struct variant_or_empty_helper<> {
-    using type = ::beman::execution::detail::empty_variant;
-};
-
-template <typename... T>
-struct variant_or_empty_helper {
-    using type = ::beman::execution::detail::meta::unique<::std::variant<::std::decay_t<T>...>>;
-};
-
-template <typename... T>
-using variant_or_empty = typename ::beman::execution::detail::variant_or_empty_helper<T...>::type;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/stoppable_source.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <typename Source>
-concept stoppable_source = requires(Source& source, const Source& csource) {
-    { csource.get_token() } -> ::beman::execution::stoppable_token;
-    { csource.stop_possible() } noexcept -> ::std::same_as<bool>;
-    { csource.stop_requested() } noexcept -> ::std::same_as<bool>;
-    { source.request_stop() } -> ::std::same_as<bool>;
-};
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/receiver.hpp"
-namespace beman::execution {
-export /* --------- */ struct receiver_t {};
-
-export /* --------- */ template <typename Rcvr>
-concept receiver =
-    ::std::derived_from<typename ::std::remove_cvref_t<Rcvr>::receiver_concept, ::beman::execution::receiver_t> &&
-    requires(const ::std::remove_cvref_t<Rcvr>& rcvr) {
-        { ::beman::execution::get_env(rcvr) } -> ::beman::execution::detail::queryable;
-    } && ::std::move_constructible<::std::remove_cvref_t<Rcvr>> &&
-    ::std::constructible_from<::std::remove_cvref_t<Rcvr>, Rcvr> && (!::std::is_final_v<::std::remove_cvref_t<Rcvr>>);
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/valid_completion_signatures.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct valid_completion_signatures_helper : ::std::false_type {};
-template <typename... Sigs>
-struct valid_completion_signatures_helper<::beman::execution::completion_signatures<Sigs...>> : ::std::true_type {};
-
-template <typename Signatures>
-concept valid_completion_signatures = valid_completion_signatures_helper<Signatures>::value;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/env_of_t.hpp"
-namespace beman::execution {
-
-#line 18 "include/beman/execution/detail/env_of_t.hpp"
-export /* --------- */ template <typename T>
-using env_of_t = decltype(::beman::execution::get_env(::std::declval<T>()));
-} // namespace beman::execution
-
-#line 17 "include/beman/execution/detail/allocator_aware_move.hpp"
-namespace beman::execution::detail {
-template <typename T, typename Context>
-
-#line 24 "include/beman/execution/detail/allocator_aware_move.hpp"
-auto allocator_aware_move(T&& obj, Context&& context) noexcept -> decltype(auto) {
-    try {
-        if constexpr (requires { ::beman::execution::get_allocator(::beman::execution::get_env(context)); }) {
-            if constexpr (decltype(::beman::execution::detail::is_product_type(obj))()) {
-                return obj.make_from(::beman::execution::get_allocator(::beman::execution::get_env(context)),
-                                     ::std::forward<T>(obj));
-            } else {
-                return ::std::make_obj_using_allocator<T>(
-                    ::beman::execution::get_allocator(::beman::execution::get_env(context)), ::std::forward<T>(obj));
-            }
-        } else {
-            return ::std::forward<T>(obj);
-        }
-    } catch (...) {
-        ::std::terminate();
-    }
-}
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/stop_token_of_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename T>
-using stop_token_of_t = ::std::remove_cvref_t<decltype(::beman::execution::get_stop_token(::std::declval<T>()))>;
-}
-#line 13 "include/beman/execution/detail/unstoppable_token.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Token>
-concept unstoppable_token = ::beman::execution::stoppable_token<Token> &&
-                            requires() { requires ::std::bool_constant<not Token::stop_possible()>::value; };
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/has_as_awaitable.hpp"
-namespace beman::execution::detail {
-template <typename T, typename Promise>
-concept has_as_awaitable = requires(T&& obj, Promise& promise) {
-    { ::std::forward<T>(obj).as_awaitable(promise) } -> ::beman::execution::detail::is_awaitable<Promise&>;
-};
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/has_completions.hpp"
-namespace beman::execution::detail {
-template <typename Receiver, typename Completions>
-concept has_completions = requires(Completions* completions) {
-    []<::beman::execution::detail::valid_completion_for<Receiver>... Signatures>(
-        ::beman::execution::completion_signatures<Signatures...>*) {}(completions);
-};
-} // namespace beman::execution::detail
-
-#line 23 "include/beman/execution/detail/default_impls.hpp"
-namespace beman::execution::detail {
-
-#line 29 "include/beman/execution/detail/default_impls.hpp"
-struct default_impls {
-    struct get_attrs_impl {
-        auto operator()(const auto&, const auto&... child) const noexcept -> decltype(auto) {
-            if constexpr (1 == sizeof...(child))
-                return (::beman::execution::detail::fwd_env(::beman::execution::get_env(child)), ...);
-            else
-                return ::beman::execution::env<>{};
-        }
-    };
-    static constexpr auto get_attrs = get_attrs_impl{};
-    struct get_env_impl {
-        auto operator()(auto, auto&, const auto& receiver) const noexcept -> decltype(auto) {
-            return ::beman::execution::detail::fwd_env(::beman::execution::get_env(receiver));
-        }
-    };
-    static constexpr auto get_env = get_env_impl{};
-    struct get_state_impl {
-        template <typename Sender, typename Receiver>
-        auto operator()(Sender&& sender, Receiver& receiver) const noexcept -> decltype(auto) {
-            auto&& data{[&sender]() -> decltype(auto) {
-                if constexpr (requires {
-                                  sender.size();
-                                  sender.template get<1>();
-                              })
-                    return sender.template get<1>();
-                else
-                    return ::beman::execution::detail::get_sender_data(::std::forward<Sender>(sender)).data;
-            }()};
-
-            return ::beman::execution::detail::allocator_aware_move(
-                ::beman::execution::detail::forward_like<Sender>(data), receiver);
-        }
-    };
-    static constexpr auto get_state = get_state_impl{};
-    struct start_impl {
-        auto operator()(auto&, auto&, auto&... ops) const noexcept -> void { (::beman::execution::start(ops), ...); }
-    };
-    static constexpr auto start = start_impl{};
-    struct complete_impl {
-        template <typename Index, typename Receiver, typename Tag, typename... Args>
-            requires ::beman::execution::detail::callable<Tag, Receiver, Args...>
-        auto operator()(Index, auto&, Receiver& receiver, Tag, Args&&... args) const noexcept -> void {
-            static_assert(Index::value == 0);
-            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
-        }
-    };
-    static constexpr auto complete = complete_impl{};
-};
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/with_await_transform.hpp"
-namespace beman::execution::detail {
-// NOLINTBEGIN(bugprone-crtp-constructor-accessibility)
-template <typename Derived>
-struct with_await_transform {
-    template <typename T>
-    auto await_transform(T&& obj) noexcept -> T&& {
-        return ::std::forward<T>(obj);
-    }
-#line 23 "include/beman/execution/detail/with_await_transform.hpp"
-    template <::beman::execution::detail::has_as_awaitable<Derived> T>
-    auto await_transform(T&& obj) noexcept(noexcept(::std::forward<T>(obj).as_awaitable(::std::declval<Derived&>())))
-        -> decltype(auto) {
-        return ::std::forward<T>(obj).as_awaitable(static_cast<Derived&>(*this));
-    }
-};
-// NOLINTEND(bugprone-crtp-constructor-accessibility)
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/receiver_of.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Receiver, typename Completions>
-concept receiver_of =
-    beman::execution::receiver<Receiver> && beman::execution::detail::has_completions<Receiver, Completions>;
-}
-#line 15 "include/beman/execution/detail/gather_signatures.hpp"
-namespace beman::execution::detail {
-template <typename...>
-concept always_true = true;
-
-template <typename, typename>
-struct same_tag;
-template <typename Tag, typename R, typename... A>
-struct same_tag<Tag, R(A...)> {
-    static constexpr bool value = ::std::same_as<Tag, R>;
-};
-template <typename Tag>
-struct bound_tag {
-    using type = Tag;
-    template <typename T>
-    using predicate = ::beman::execution::detail::same_tag<Tag, T>;
-};
-
-template <typename, template <typename...> class>
-struct gather_signatures_apply;
-template <typename R, typename... A, template <typename...> class Transform>
-    requires requires {
-        typename ::beman::execution::detail::indirect_meta_apply<
-            ::beman::execution::detail::always_true<R>>::template meta_apply<Transform, A...>;
-    }
-struct gather_signatures_apply<R(A...), Transform> {
-    using type = typename ::beman::execution::detail::indirect_meta_apply<
-        ::beman::execution::detail::always_true<R>>::template meta_apply<Transform, A...>;
-};
-
-template <::beman::execution::detail::valid_completion_signatures,
-          template <typename...> class,
-          template <typename...> class>
-struct gather_signatures_helper;
-
-template <typename... Signatures, template <typename...> class Tuple, template <typename...> class Variant>
-    requires requires {
-        requires always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
-    } && requires {
-        typename ::beman::execution::detail::indirect_meta_apply<
-            always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>>::
-            template meta_apply<
-                Variant,
-                typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
-    }
-struct gather_signatures_helper<::beman::execution::completion_signatures<Signatures...>, Tuple, Variant> {
-    using type = typename ::beman::execution::detail::indirect_meta_apply<
-        always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>>::
-        template meta_apply<Variant,
-                            typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
-};
-
-template <typename Tag,
-          ::beman::execution::detail::valid_completion_signatures signatures,
-          template <typename...> class Tuple,
-          template <typename...> class Variant>
-    requires requires {
-        typename ::beman::execution::detail::gather_signatures_helper<
-            ::beman::execution::detail::meta::filter_tag<::beman::execution::detail::same_tag, Tag, signatures>,
-            Tuple,
-            Variant>::type;
-    }
-using gather_signatures = typename ::beman::execution::detail::gather_signatures_helper<
-    ::beman::execution::detail::meta::filter_tag<::beman::execution::detail::same_tag, Tag, signatures>,
-    Tuple,
-    Variant>::type;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/env_promise.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/env_promise.hpp"
-export /* --------- */ template <typename Env>
-struct env_promise : ::beman::execution::detail::with_await_transform<Env> {
-    auto get_return_object() noexcept -> void;
-    auto initial_suspend() noexcept -> ::std::suspend_always;
-    auto final_suspend() noexcept -> ::std::suspend_always;
-    auto unhandled_exception() noexcept -> void;
-    auto return_void() noexcept -> void;
-    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<>;
-    auto get_env() const noexcept -> const Env&;
-};
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/impls_for.hpp"
-namespace beman::execution::detail {
-template <typename Tag>
-struct impls_for : ::beman::execution::detail::default_impls {};
-} // namespace beman::execution::detail
-
-#line 19 "include/beman/execution/detail/operation_state_task.hpp"
-namespace beman::execution::detail {
-template <typename Receiver>
-struct operation_state_task;
-
-template <typename Receiver>
-struct connect_awaitable_promise;
-} // namespace beman::execution::detail
-
-#line 29 "include/beman/execution/detail/operation_state_task.hpp"
-template <typename Receiver>
-struct beman::execution::detail::connect_awaitable_promise
-    : ::beman::execution::detail::with_await_transform<connect_awaitable_promise<Receiver>> {
-    connect_awaitable_promise(auto&&, Receiver& rcvr) noexcept : receiver(rcvr) {}
-    auto              initial_suspend() noexcept -> ::std::suspend_always { return {}; }
-    [[noreturn]] auto final_suspend() noexcept -> ::std::suspend_always { ::std::terminate(); }
-    [[noreturn]] auto unhandled_exception() noexcept -> void { ::std::terminate(); }
-    [[noreturn]] auto return_void() noexcept -> void { ::std::terminate(); }
-
-    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<> {
-        ::beman::execution::set_stopped(::std::move(this->receiver));
-        return ::std::noop_coroutine();
-    }
-#line 43 "include/beman/execution/detail/operation_state_task.hpp"
-    auto get_env() const noexcept -> ::beman::execution::env_of_t<Receiver> {
-        return ::beman::execution::get_env(this->receiver);
-    }
-#line 47 "include/beman/execution/detail/operation_state_task.hpp"
-    auto get_return_object() noexcept -> ::beman::execution::detail::operation_state_task<Receiver>;
-
-  private:
-    Receiver& receiver;
-};
-
-#line 55 "include/beman/execution/detail/operation_state_task.hpp"
-template <typename Receiver>
-struct beman::execution::detail::operation_state_task {
-    using operation_state_concept = ::beman::execution::operation_state_t;
-    using promise_type            = ::beman::execution::detail::connect_awaitable_promise<Receiver>;
-
-    explicit operation_state_task(::std::coroutine_handle<> hndl) noexcept : handle(hndl) {}
-    operation_state_task(const operation_state_task&) = delete;
-    operation_state_task(operation_state_task&& other) noexcept : handle(::std::exchange(other.handle, {})) {}
-    ~operation_state_task() {
-        if (this->handle)
-            this->handle.destroy();
-    }
-    auto operator=(operation_state_task&&) -> operation_state_task&      = delete;
-    auto operator=(const operation_state_task&) -> operation_state_task& = delete;
-
-    auto start() & noexcept -> void { this->handle.resume(); }
-
-    ::std::coroutine_handle<> handle;
-};
-
-#line 77 "include/beman/execution/detail/operation_state_task.hpp"
-template <typename Receiver>
-auto beman::execution::detail::connect_awaitable_promise<Receiver>::get_return_object() noexcept
-    -> ::beman::execution::detail::operation_state_task<Receiver> {
-    return ::beman::execution::detail::operation_state_task<Receiver>(
-        std::coroutine_handle<connect_awaitable_promise>::from_promise(*this));
-}
-#line 18 "include/beman/execution/detail/sender.hpp"
-namespace beman::execution {
-export /* --------- */ struct sender_t {};
-} // namespace beman::execution
-namespace beman::execution::detail {
-template <typename Sender>
-concept is_sender = ::std::derived_from<typename Sender::sender_concept, ::beman::execution::sender_t>;
-
-template <typename Sender>
-concept enable_sender =
-    ::beman::execution::detail::is_sender<Sender> ||
-    ::beman::execution::detail::is_awaitable<Sender,
-                                             ::beman::execution::detail::env_promise<::beman::execution::env<>>>;
-} // namespace beman::execution::detail
-namespace beman::execution {
-export /* --------- */ template <typename Sender>
-concept sender = ::beman::execution::detail::enable_sender<::std::remove_cvref_t<Sender>> &&
-                 requires(const ::std::remove_cvref_t<Sender>& sndr) {
-                     { ::beman::execution::get_env(sndr) } -> ::beman::execution::detail::queryable;
-                 } && ::std::move_constructible<::std::remove_cvref_t<Sender>> &&
-                 ::std::constructible_from<::std::remove_cvref_t<Sender>, Sender>;
-} // namespace beman::execution
-
-#line 24 "include/beman/execution/detail/connect_awaitable.hpp"
-namespace beman::execution::detail {
-
-#line 30 "include/beman/execution/detail/connect_awaitable.hpp"
-template <typename T>
-struct awaiter_set_value {
-    using type = ::beman::execution::set_value_t(T);
-};
-
-#line 39 "include/beman/execution/detail/connect_awaitable.hpp"
-template <>
-struct awaiter_set_value<void> {
-    using type = ::beman::execution::set_value_t();
-};
-
-#line 49 "include/beman/execution/detail/connect_awaitable.hpp"
-template <typename Awaiter, typename Receiver>
-using awaiter_completion_signatures = ::beman::execution::completion_signatures<
-    typename ::beman::execution::detail::awaiter_set_value<::beman::execution::detail::await_result_type<
-        Awaiter,
-        ::beman::execution::detail::connect_awaitable_promise<Receiver>>>::type,
-    ::beman::execution::set_error_t(::std::exception_ptr),
-    ::beman::execution::set_stopped_t()>;
-
-#line 62 "include/beman/execution/detail/connect_awaitable.hpp"
-template <typename Awaiter, ::beman::execution::receiver Receiver>
-auto connect_awaitable(Awaiter awaiter, Receiver receiver)
-    -> ::beman::execution::detail::operation_state_task<Receiver>
-    requires ::beman::execution::
-        receiver_of<Receiver, ::beman::execution::detail::awaiter_completion_signatures<Awaiter, Receiver>>
+namespace beman::execution
 {
-
-#line 70 "include/beman/execution/detail/connect_awaitable.hpp"
-    using result_type =
-        ::beman::execution::detail::await_result_type<Awaiter,
-                                                      ::beman::execution::detail::connect_awaitable_promise<Receiver>>;
-
-    ::std::exception_ptr ep;
-    try {
-        if constexpr (std::same_as<void, result_type>) {
-            co_await ::std::move(awaiter);
-            co_await ::beman::execution::detail::suspend_complete(::beman::execution::set_value,
-                                                                  ::std::move(receiver));
-        } else {
-            co_await ::beman::execution::detail::suspend_complete(
-                ::beman::execution::set_value, ::std::move(receiver), co_await ::std::move(awaiter));
-        }
-    } catch (...) {
-        ep = ::std::current_exception();
-    }
-    co_await ::beman::execution::detail::suspend_complete(::beman::execution::set_error, ::std::move(receiver), ep);
-}
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/state_type.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Receiver>
-using state_type = ::std::decay_t<::beman::execution::detail::call_result_t<
-    decltype(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_state),
-    Sender,
-    Receiver&>>;
-}
-#line 15 "include/beman/execution/detail/schedule.hpp"
-namespace beman::execution {
-export /* --------- */ struct schedule_t {
-    template <typename Scheduler>
-        requires(not requires(Scheduler&& sched) {
-                    { ::std::forward<Scheduler>(sched).schedule() } -> ::beman::execution::sender;
-                })
-    auto operator()(Scheduler&& sched) const =
-        BEMAN_EXECUTION_DELETE("the scheduler needs a schedule() member returning a sender");
-
-    template <typename Scheduler>
-        requires requires(Scheduler&& sched) {
-            { ::std::forward<Scheduler>(sched).schedule() } -> ::beman::execution::sender;
-        }
-    auto operator()(Scheduler&& sched) const noexcept(noexcept(std::forward<Scheduler>(sched).schedule())) {
-        return std::forward<Scheduler>(sched).schedule();
-    }
-};
-
-export /* --------- */ inline constexpr ::beman::execution::schedule_t schedule{};
-} // namespace beman::execution
-
-#line 15 "include/beman/execution/detail/sender_adaptor_closure.hpp"
-namespace beman::execution::detail::pipeable {
-struct sender_adaptor_closure_base {};
-} // namespace beman::execution::detail::pipeable
-
-namespace beman::execution {
-// NOLINTBEGIN(bugprone-crtp-constructor-accessibility)
-export /* --------- */ template <typename>
-struct sender_adaptor_closure : ::beman::execution::detail::pipeable::sender_adaptor_closure_base {};
-// NOLINTEND(bugprone-crtp-constructor-accessibility)
-
-} // namespace beman::execution
-
-namespace beman::execution::detail {
-template <typename Closure>
-concept is_sender_adaptor_closure =
-    ::std::derived_from<::std::decay_t<Closure>, ::beman::execution::sender_adaptor_closure<::std::decay_t<Closure>>>;
-}
-#line 33 "include/beman/execution/detail/sender_adaptor_closure.hpp"
-namespace beman::execution::detail::pipeable {
-export /* --------- */ template <::beman::execution::sender Sender, typename Adaptor>
-    requires(!::beman::execution::sender<Adaptor>) &&
-            ::std::derived_from<::std::decay_t<Adaptor>,
-                                ::beman::execution::sender_adaptor_closure<::std::decay_t<Adaptor>>> &&
-            requires(Sender&& sender, Adaptor&& adaptor) {
-                { adaptor(::std::forward<Sender>(sender)) } -> ::beman::execution::sender;
-            }
-auto operator|(Sender&& sender, Adaptor&& adaptor) {
-    return adaptor(::std::forward<Sender>(sender));
-}
-} // namespace beman::execution::detail::pipeable
-
-#line 15 "include/beman/execution/detail/sender_for.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Tag>
-concept sender_for = ::beman::execution::sender<Sender> && ::std::same_as<::beman::execution::tag_of_t<Sender>, Tag>;
-}
-#line 14 "include/beman/execution/detail/sender_has_affine_on.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Env>
-concept sender_has_affine_on =
-    beman::execution::sender<::std::remove_cvref_t<Sender>> && requires(Sender&& sndr, const Env& env) {
-        sndr.template get<0>();
-        { sndr.template get<0>().affine_on(std::forward<Sender>(sndr), env) } -> ::beman::execution::sender;
-    };
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/default_domain.hpp"
-namespace beman::execution {
-
-#line 28 "include/beman/execution/detail/default_domain.hpp"
-export /* --------- */ struct default_domain {
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable... Env>
-        requires(sizeof...(Env) <= 1) && requires(Sender&& sender, Env&&... env) {
-            ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
-                                                                    ::std::forward<Env>(env)...);
-        }
-    static constexpr auto transform_sender(Sender&& sender, Env&&... env) noexcept(
-        noexcept(::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
-                                                                         ::std::forward<Env>(env)...)))
-        -> ::beman::execution::sender decltype(auto) {
-        return ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
-                                                                       ::std::forward<Env>(env)...);
-    }
-#line 42 "include/beman/execution/detail/default_domain.hpp"
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable... Env>
-        requires(sizeof...(Env) <= 1) && (not requires(Sender&& sender, Env&&... env) {
-                    ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
-                                                                            ::std::forward<Env>(env)...);
-                })
-    static constexpr auto transform_sender(Sender&& sender,
-                                           Env&&...) noexcept(noexcept(::std::forward<Sender>(sender)))
-        -> ::beman::execution::sender decltype(auto) {
-        return ::std::forward<Sender>(sender);
-    }
-#line 53 "include/beman/execution/detail/default_domain.hpp"
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
-        requires requires(Sender&& sender, Env&& env) {
-            ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
-                                                                 ::std::forward<Env>(env));
-        }
-    static constexpr auto transform_env(Sender&& sender, Env&& env) noexcept -> ::beman::execution::detail::queryable
-        decltype(auto) {
-        return ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
-                                                                    ::std::forward<Env>(env));
-    }
-#line 64 "include/beman/execution/detail/default_domain.hpp"
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
-        requires(not requires(Sender&& sender, Env&& env) {
-            ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
-                                                                 ::std::forward<Env>(env));
-        })
-    static constexpr auto transform_env(Sender&&, Env&& env) noexcept -> ::beman::execution::detail::queryable
-        decltype(auto) {
-        return static_cast<Env>(::std::forward<Env>(env));
-    }
-#line 74 "include/beman/execution/detail/default_domain.hpp"
-    template <typename Tag, ::beman::execution::sender Sender, typename... Args>
-        requires requires(Sender&& sender, Args&&... args) {
-            Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-        }
-    static constexpr auto apply_sender(Tag, Sender&& sender, Args&&... args) noexcept(noexcept(
-        Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...))) -> decltype(auto) {
-        return Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-    }
-};
-} // namespace beman::execution
-
-#line 18 "include/beman/execution/detail/spawn_get_allocator.hpp"
-namespace beman::execution::detail {
-template <::beman::execution::sender Sndr, typename Ev>
-auto spawn_get_allocator(const Sndr& sndr, const Ev& ev) {
-    if constexpr (requires { ::beman::execution::get_allocator(ev); }) {
-        return ::std::pair(::beman::execution::get_allocator(ev), ev);
-    } else if constexpr (requires { ::beman::execution::get_allocator(::beman::execution::get_env(sndr)); }) {
-        auto alloc{::beman::execution::get_allocator(::beman::execution::get_env(sndr))};
-        return ::std::pair(alloc,
-                           ::beman::execution::detail::join_env(
-                               ::beman::execution::prop(::beman::execution::get_allocator, alloc), ev));
-    } else {
-        return ::std::pair(::std::allocator<void>{}, ev);
-    }
-}
-#line 33 "include/beman/execution/detail/spawn_get_allocator.hpp"
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/basic_state.hpp"
-namespace beman::execution::detail {
-
-#line 24 "include/beman/execution/detail/basic_state.hpp"
-export /* --------- */ template <typename Sender, typename Receiver>
-struct basic_state {
-    basic_state(Sender&& sender, Receiver&& rcvr) noexcept(true)
-        : receiver(::std::move(rcvr)),
-          state(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_state(
-              ::std::forward<Sender>(sender), this->receiver)) {}
-
-    Receiver                                                 receiver;
-    ::beman::execution::detail::state_type<Sender, Receiver> state;
-};
-template <typename Sender, typename Receiver>
-basic_state(Sender&&, Receiver&&) -> basic_state<Sender&&, Receiver>;
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/env_type.hpp"
-namespace beman::execution::detail {
-
-#line 22 "include/beman/execution/detail/env_type.hpp"
-template <typename Index, typename Sender, typename Receiver>
-using env_type = ::beman::execution::detail::call_result_t<
-    decltype(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_env),
-    Index,
-    ::beman::execution::detail::state_type<Sender, Receiver>&,
-    const Receiver&>;
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/almost_scheduler.hpp"
-namespace beman::execution::detail {
-
-#line 24 "include/beman/execution/detail/almost_scheduler.hpp"
-template <typename Scheduler>
-concept almost_scheduler = ::std::derived_from<typename ::std::remove_cvref_t<Scheduler>::scheduler_concept,
-                                               ::beman::execution::scheduler_t> &&
-                           ::beman::execution::detail::queryable<Scheduler> &&
-                           requires(Scheduler&& sched) {
-                               {
-                                   ::beman::execution::schedule(::std::forward<Scheduler>(sched))
-                               } -> ::beman::execution::sender;
-                           } && ::std::equality_comparable<::std::remove_cvref_t<Scheduler>> &&
-                           ::std::copy_constructible<::std::remove_cvref_t<Scheduler>>;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/transform_sender.hpp"
-namespace beman::execution::detail {
-template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) &&
-            requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            } &&
-            (::std::same_as<::std::remove_cvref_t<Sender>,
-                            std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
-                                ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
-constexpr auto transform_sender(Domain, Sender&& sender, const Env&...) noexcept -> ::beman::execution::sender auto {
-    return ::std::forward<Sender>(sender);
-}
-#line 27 "include/beman/execution/detail/transform_sender.hpp"
-template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) &&
-            requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            } &&
-            (!::std::same_as<::std::remove_cvref_t<Sender>,
-                             std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
-                                 ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
-constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept -> ::beman::execution::sender
-    decltype(auto) {
-    return ::beman::execution::detail::transform_sender(
-        dom, dom.transform_sender(::std::forward<Sender>(sender), env...), env...);
-}
-#line 41 "include/beman/execution/detail/transform_sender.hpp"
-template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(not requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            }) && ::std::same_as<::std::remove_cvref_t<Sender>,
-                                 ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
-                                     ::std::declval<Sender>(), ::std::declval<Env>()...))>>
-constexpr auto
-    transform_sender(Domain, Sender&& sender, const Env&...) noexcept(noexcept(::std::forward<Sender>(sender)))
-        -> ::beman::execution::sender auto {
-    return sender;
-}
-#line 53 "include/beman/execution/detail/transform_sender.hpp"
-template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(not requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            }) &&
-            (!::std::same_as<::std::remove_cvref_t<Sender>,
-                             ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
-                                 ::std::declval<Sender>(), ::std::declval<Env>()...))>>)
-constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept(noexcept(
-    ::beman::execution::default_domain{}.transform_sender(::std::declval<Sender>(), ::std::declval<Env>()...)))
-    -> ::beman::execution::sender decltype(auto) {
-    return ::beman::execution::detail::transform_sender(
-        dom, ::beman::execution::default_domain{}.transform_sender(::std::forward<Sender>(sender), env...), env...);
-}
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) &&
-            requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            } &&
-            (::std::same_as<::std::remove_cvref_t<Sender>,
-                            std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
-                                ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
-constexpr auto transform_sender(Domain, Sender&& sender, const Env&...) noexcept -> ::beman::execution::sender
-    decltype(auto) {
-    return ::std::forward<Sender>(sender);
-}
-#line 82 "include/beman/execution/detail/transform_sender.hpp"
-export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) &&
-            requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            } &&
-            (!::std::same_as<::std::remove_cvref_t<Sender>,
-                             std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
-                                 ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
-constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept -> ::beman::execution::sender
-    auto {
-    return ::beman::execution::detail::transform_sender(
-        dom, dom.transform_sender(::std::forward<Sender>(sender), env...), env...);
-}
-#line 96 "include/beman/execution/detail/transform_sender.hpp"
-export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) && (not requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            }) &&
-            ::std::same_as<::std::remove_cvref_t<Sender>,
-                           ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
-                               ::std::declval<Sender>(), ::std::declval<Env>()...))>>
-constexpr auto
-    transform_sender(Domain, Sender&& sender, const Env&...) noexcept(noexcept(::std::forward<Sender>(sender)))
-        -> ::beman::execution::sender decltype(auto) {
-    return ::std::forward<Sender>(sender);
-}
-#line 109 "include/beman/execution/detail/transform_sender.hpp"
-export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) && (not requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            }) &&
-            (!::std::same_as<::std::remove_cvref_t<Sender>,
-                             ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
-                                 ::std::declval<Sender>(), ::std::declval<Env>()...))>>)
-constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept(
-    noexcept(::beman::execution::detail::transform_sender(
-        dom,
-        ::beman::execution::default_domain{}.transform_sender(::std::declval<Sender>(), ::std::declval<Env>()...),
-        env...))) -> ::beman::execution::sender decltype(auto) {
-    return ::beman::execution::detail::transform_sender(
-        dom, ::beman::execution::default_domain{}.transform_sender(::std::forward<Sender>(sender), env...), env...);
-}
-} // namespace beman::execution
-
-#line 18 "include/beman/execution/detail/sender_adaptor.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <typename Adaptor, typename... T>
-struct sender_adaptor : ::beman::execution::detail::product_type<::std::decay_t<Adaptor>, ::std::decay_t<T>...>,
-                        ::beman::execution::sender_adaptor_closure<sender_adaptor<Adaptor, T...>> {
-    template <::beman::execution::sender Sender, typename Self>
-    static auto apply(Sender&& sender, Self&& self) {
-        return [&self, &sender]<::std::size_t... I>(::std::index_sequence<I...>) {
-            auto&& fun(self.template get<0>());
-            return fun(::std::forward<Sender>(sender),
-                       ::beman::execution::detail::forward_like<Self>(self.template get<I + 1>())...);
-        }(::std::make_index_sequence<sender_adaptor::size() - 1u>{});
-    }
-    template <::beman::execution::sender Sender>
-    auto operator()(Sender&& sender) {
-        return apply(::std::forward<Sender>(sender), ::std::move(*this));
-    }
-    template <::beman::execution::sender Sender>
-    auto operator()(Sender&& sender) const {
-        return apply(::std::forward<Sender>(sender), *this);
-    }
-};
-template <typename... T>
-sender_adaptor(T&&...) -> sender_adaptor<T...>;
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/sched_env.hpp"
-namespace beman::execution::detail {
-template <typename Scheduler>
-class sched_env {
-  private:
-    Scheduler sched;
-
-  public:
-    template <typename S>
-    explicit sched_env(S sch) : sched(::std::move(sch)) {}
-
-    auto query(const ::beman::execution::get_scheduler_t&) const noexcept { return this->sched; }
-    auto query(const ::beman::execution::get_domain_t& q) const noexcept {
-        if constexpr (requires { this->sched.query(q); })
-            return this->sched.query(q);
-        else
-            return ::beman::execution::default_domain{};
-    }
-};
-
-template <typename Scheduler>
-sched_env(Scheduler&&) -> sched_env<::std::remove_cvref_t<Scheduler>>;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/apply_sender.hpp"
-namespace beman::execution {
-
-#line 19 "include/beman/execution/detail/apply_sender.hpp"
-export /* --------- */ template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
-    requires requires(Domain domain, Tag tag, Sender&& sender, Args&&... args) {
-        domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-    }
-constexpr auto apply_sender(Domain domain, Tag, Sender&& sender, Args&&... args) noexcept(noexcept(
-    domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...))) -> decltype(auto) {
-    return domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-}
-#line 32 "include/beman/execution/detail/apply_sender.hpp"
-export /* --------- */ template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
-    requires(not requires(Domain domain, Tag tag, Sender&& sender, Args&&... args) {
-                domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-            }) && requires(Tag tag, Sender&& sender, Args&&... args) {
-        beman::execution::default_domain().apply_sender(
-            Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-    }
-constexpr auto apply_sender(Domain, Tag, Sender&& sender, Args&&... args) noexcept(
-    noexcept(beman::execution::default_domain().apply_sender(Tag(),
-                                                             ::std::forward<Sender>(sender),
-                                                             ::std::forward<Args>(args)...))) -> decltype(auto) {
-    return beman::execution::default_domain().apply_sender(
-        Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-}
-#line 47 "include/beman/execution/detail/apply_sender.hpp"
-} // namespace beman::execution
-
-#line 12 "include/beman/execution/detail/nested_sender_has_affine_on.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Env>
-concept nested_sender_has_affine_on = requires(Sender&& sndr, const Env& env) {
-    { sndr.template get<2>() } -> ::beman::execution::detail::sender_has_affine_on<Env>;
-};
-} // namespace beman::execution::detail
-
-#line 25 "include/beman/execution/detail/basic_receiver.hpp"
-namespace beman::execution::detail {
-
-#line 31 "include/beman/execution/detail/basic_receiver.hpp"
-template <typename Sender, typename Receiver, typename Index>
-    requires ::beman::execution::detail::
-        valid_specialization<::beman::execution::detail::env_type, Index, Sender, Receiver>
-    struct basic_receiver {
-    friend struct ::beman::execution::get_env_t;
-    friend struct ::beman::execution::set_error_t;
-    friend struct ::beman::execution::set_stopped_t;
-    friend struct ::beman::execution::set_value_t;
-
-    using receiver_concept                = ::beman::execution::receiver_t;
-    using tag_t                           = ::beman::execution::tag_of_t<Sender>;
-    using state_t                         = ::beman::execution::detail::state_type<Sender, Receiver>;
-    static constexpr const auto& complete = ::beman::execution::detail::impls_for<tag_t>::complete;
-    ::beman::execution::detail::basic_state<Sender, Receiver>* op{};
-
-  private:
-    template <typename... Args>
-    auto set_value(Args&&... args) && noexcept -> void
-        requires ::beman::execution::detail::
-            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_value_t, Args...>
-    {
-        this->complete(Index(),
-                       this->op->state,
-                       this->op->receiver,
-                       ::beman::execution::set_value_t(),
-                       ::std::forward<Args>(args)...);
-    }
-#line 59 "include/beman/execution/detail/basic_receiver.hpp"
-    template <typename Error>
-    auto set_error(Error&& error) && noexcept -> void
-        requires ::beman::execution::detail::
-            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_error_t, Error>
-    {
-        this->complete(Index(),
-                       this->op->state,
-                       this->op->receiver,
-                       ::beman::execution::set_error_t(),
-                       ::std::forward<Error>(error));
-    }
-#line 71 "include/beman/execution/detail/basic_receiver.hpp"
-    auto set_stopped() && noexcept -> void
-        requires ::beman::execution::detail::
-            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_stopped_t>
-    {
-        this->complete(Index(), this->op->state, this->op->receiver, ::beman::execution::set_stopped_t());
-    }
-#line 78 "include/beman/execution/detail/basic_receiver.hpp"
-    auto get_env() const noexcept -> ::beman::execution::detail::env_type<Index, Sender, Receiver> {
-        return ::beman::execution::detail::impls_for<tag_t>::get_env(Index(), this->op->state, this->op->receiver);
-    }
-};
-} // namespace beman::execution::detail
-
-#line 25 "include/beman/execution/detail/get_completion_scheduler.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Tag>
-struct get_completion_scheduler_t;
-
-template <typename Tag>
-struct get_completion_scheduler_t : ::beman::execution::forwarding_query_t {
-    template <typename Env>
-        requires(not requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                    env.query(self);
-                })
-    auto operator()(Env&&) const noexcept =
-        BEMAN_EXECUTION_DELETE("The environment needs a query(get_completion_scheduler_t) member");
-
-    template <typename Env>
-        requires(requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                    env.query(self);
-                } && (not requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                     { env.query(self) } noexcept;
-                 }))
-    auto operator()(Env&&) const noexcept =
-        BEMAN_EXECUTION_DELETE("The environment's query(get_completion_scheduler_t) has to be noexcept");
-
-    template <typename Env>
-        requires(
-                    requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                        env.query(self);
-                    } &&
-                    requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                        { env.query(self) } noexcept;
-                    } &&
-                    (not requires(const get_completion_scheduler_t&                                  self,
-                                  const get_completion_scheduler_t<::beman::execution::set_value_t>& value_self,
-                                  const ::std::remove_cvref_t<Env>&                                  env) {
-                        { env.query(self) } noexcept -> ::beman::execution::detail::almost_scheduler;
-                        {
-                            ::beman::execution::get_env(::beman::execution::schedule(env.query(self)))
-                                .query(value_self)
-                        } -> ::beman::execution::detail::decayed_same_as<decltype(env.query(self))>;
-                    }))
-    auto operator()(Env&&) const noexcept =
-        BEMAN_EXECUTION_DELETE("The environment's query(get_completion_scheduler_t) has to return a scheduler");
-
-    template <typename Env>
-        requires requires(const get_completion_scheduler_t&                                  self,
-                          const get_completion_scheduler_t<::beman::execution::set_value_t>& value_self,
-                          const ::std::remove_cvref_t<Env>&                                  env) {
-            { env.query(self) } noexcept -> ::beman::execution::detail::almost_scheduler;
-            {
-                ::beman::execution::get_env(::beman::execution::schedule(env.query(self))).query(value_self)
-            } -> ::beman::execution::detail::decayed_same_as<decltype(env.query(self))>;
-        }
-    auto operator()(Env&& env) const noexcept {
-        return ::std::as_const(env).query(*this);
-    }
-};
-
-export /* --------- */ template <::beman::execution::detail::completion_tag Tag>
-inline constexpr get_completion_scheduler_t<Tag> get_completion_scheduler{};
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/scheduler.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Scheduler>
-concept scheduler = ::beman::execution::detail::almost_scheduler<Scheduler> && requires(Scheduler&& sched) {
-    {
-        ::beman::execution::get_completion_scheduler<::beman::execution::set_value_t>(
-            ::beman::execution::get_env(::beman::execution::schedule(::std::forward<Scheduler>(sched))))
-    } -> ::beman::execution::detail::decayed_same_as<Scheduler>;
-};
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/sched_attrs.hpp"
-namespace beman::execution::detail {
-
-template <typename Scheduler>
-class sched_attrs {
-  private:
-    Scheduler sched;
-
-  public:
-    template <typename S>
-        requires(!::std::same_as<sched_attrs, ::std::remove_cvref_t<S>>)
-    explicit sched_attrs(S&& s) : sched(::std::forward<S>(s)) {}
-
-    template <typename Tag>
-    auto query(const ::beman::execution::get_completion_scheduler_t<Tag>&) const noexcept {
-        return this->sched;
-    }
-#line 36 "include/beman/execution/detail/sched_attrs.hpp"
-    template <typename T = bool>
-        requires requires(Scheduler&& s) { s.query(::beman::execution::get_domain); }
-    auto query(const ::beman::execution::get_domain_t& q, T = true) const noexcept {
-        return this->sched.query(q);
-    }
-};
-
-template <typename Scheduler>
-sched_attrs(Scheduler&&) -> sched_attrs<::std::remove_cvref_t<Scheduler>>;
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/completion_domain.hpp"
-namespace beman::execution::detail {
-struct completion_domain_undefined {};
-template <typename, typename>
-struct completion_domain_merge {};
-template <typename T>
-struct completion_domain_merge<T, T> {
-    using type = T;
-};
-template <typename T>
-struct completion_domain_merge<completion_domain_undefined, T> {
-    using type = T;
-};
-template <typename T>
-struct completion_domain_merge<T, completion_domain_undefined> {
-    using type = T;
-};
-template <>
-struct completion_domain_merge<completion_domain_undefined, completion_domain_undefined> {
-    using type = completion_domain_undefined;
-};
-
-#line 43 "include/beman/execution/detail/completion_domain.hpp"
-template <typename Default = ::beman::execution::default_domain, typename Sender>
-constexpr auto completion_domain(const Sender& sender) noexcept {
-
-    static_assert(::beman::execution::sender<Sender>);
-    constexpr auto get = []<typename Tag>(Tag, const Sender& sender) {
-        if constexpr (requires {
-                          ::beman::execution::get_domain(
-                              ::beman::execution::get_completion_scheduler<Tag>(::beman::execution::get_env(sender)));
-                      }) {
-            return ::beman::execution::get_domain(
-                ::beman::execution::get_completion_scheduler<Tag>(::beman::execution::get_env(sender)));
-        } else {
-            return completion_domain_undefined{};
-        }
-    };
-
-    using type = typename completion_domain_merge<
-        typename completion_domain_merge<decltype(get(::beman::execution::set_error, sender)),
-                                         decltype(get(::beman::execution::set_stopped, sender))>::type,
-        decltype(get(::beman::execution::set_value, sender))>::type;
-    return ::std::conditional_t<::std::same_as<type, completion_domain_undefined>, Default, type>();
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/get_delegation_scheduler.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_delegation_scheduler_t {
-    template <typename Env>
-        requires requires(Env&& env, const get_delegation_scheduler_t& g) {
-            { ::std::as_const(env).query(g) } noexcept -> ::beman::execution::scheduler;
-        }
-    auto operator()(Env&& env) const noexcept {
-        return ::std::as_const(env).query(*this);
-    }
-    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
-};
-
-export /* --------- */ inline constexpr get_delegation_scheduler_t get_delegation_scheduler{};
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/get_domain_late.hpp"
-namespace beman::execution::detail {
-template <typename T>
-concept not_void = !::std::same_as<T, void>;
-
-template <typename Tag>
-struct get_domain_late_helper {
-    template <typename Sender, typename Env>
-    static constexpr auto get(const Sender& sender, const Env& env) noexcept {
-        if constexpr (requires {
-                          {
-                              ::beman::execution::get_domain(::beman::execution::get_env(sender))
-                          } -> ::beman::execution::detail::not_void;
-                      })
-            return ::beman::execution::get_domain(::beman::execution::get_env(sender));
-        else if constexpr (requires {
-                               {
-                                   ::beman::execution::detail::completion_domain<void>(sender)
-                               } -> ::beman::execution::detail::not_void;
-                           })
-            return ::beman::execution::detail::completion_domain<void>(sender);
-        else if constexpr (requires {
-                               { ::beman::execution::get_domain(env) } -> ::beman::execution::detail::not_void;
-                           })
-            return ::beman::execution::get_domain(env);
-        else if constexpr (requires {
-                               {
-                                   ::beman::execution::get_domain(::beman::execution::get_scheduler(env))
-                               } -> ::beman::execution::detail::not_void;
-                           })
-            return ::beman::execution::get_domain(::beman::execution::get_scheduler(env));
-        else
-            return ::beman::execution::default_domain();
-    }
-};
-template <typename Sender, typename Env>
-constexpr auto get_domain_late(const Sender& sender, const Env& env) noexcept {
-    using tag_t = ::beman::execution::tag_of_t<Sender>;
-    return ::beman::execution::detail::get_domain_late_helper<tag_t>::get(sender, env);
-}
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/get_domain_early.hpp"
-namespace beman::execution::detail {
-template <typename Sender>
-constexpr auto get_domain_early(const Sender& sender) noexcept {
-    if constexpr (requires { ::beman::execution::get_domain(::beman::execution::get_env(sender)); })
-        return decltype(::beman::execution::get_domain(::beman::execution::get_env(sender))){};
-    else if constexpr (requires { ::beman::execution::detail::completion_domain(sender); })
-        return decltype(::beman::execution::detail::completion_domain(sender)){};
-    else
-        return ::beman::execution::default_domain{};
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/schedule_result_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <::beman::execution::scheduler Scheduler>
-using schedule_result_t = decltype(::beman::execution::schedule(::std::declval<Scheduler>()));
-}
-#line 28 "include/beman/execution/detail/run_loop.hpp"
-namespace beman::execution {
-export /* --------- */ class run_loop {
-  private:
-    struct scheduler;
-
-    struct env {
-        run_loop* loop;
-
-        template <typename Completion>
-        auto query(const ::beman::execution::get_completion_scheduler_t<Completion>&) const noexcept -> scheduler {
-            return {this->loop};
-        }
-    };
-
-    struct opstate_base : ::beman::execution::detail::virtual_immovable {
-        opstate_base* next{};
-        virtual auto  execute() noexcept -> void = 0;
-    };
-
-    template <typename Receiver>
-    struct opstate : opstate_base {
-        using operation_state_concept = ::beman::execution::operation_state_t;
-
-        run_loop* loop;
-        Receiver  receiver;
-
-        // NOLINTBEGIN(misc-no-recursion)
-        template <typename R>
-        opstate(run_loop* l, R&& rcvr) : loop(l), receiver(::std::forward<Receiver>(rcvr)) {}
-        auto start() & noexcept -> void { this->loop->push_back(this); }
-        // NOLINTEND(misc-no-recursion)
-        auto execute() noexcept -> void override {
-            using token = decltype(::beman::execution::get_stop_token(::beman::execution::get_env(this->receiver)));
-            if constexpr (not ::beman::execution::unstoppable_token<token>) {
-                if (::beman::execution::get_stop_token(::beman::execution::get_env(this->receiver)).stop_requested())
-                    ::beman::execution::set_stopped(::std::move(this->receiver));
-                else
-                    ::beman::execution::set_value(::std::move(this->receiver));
-            } else
-                ::beman::execution::set_value(::std::move(this->receiver));
-        }
-    };
-    struct sender {
-        using sender_concept = ::beman::execution::sender_t;
-        template <typename Env = ::beman::execution::env<>>
-        auto get_completion_signatures(Env&& env) const noexcept {
-            if constexpr (::beman::execution::unstoppable_token<decltype(::beman::execution::get_stop_token(env))>)
-                return ::beman::execution::completion_signatures<::beman::execution::set_value_t()>{};
-            else
-                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(),
-                                                                 ::beman::execution::set_stopped_t()>{};
-        }
-#line 81 "include/beman/execution/detail/run_loop.hpp"
-        run_loop* loop;
-
-        auto get_env() const noexcept -> env { return {this->loop}; }
-        template <typename Receiver>
-        auto connect(Receiver&& receiver) noexcept -> opstate<::std::decay_t<Receiver>> {
-            return {this->loop, ::std::forward<Receiver>(receiver)};
-        }
-    };
-    struct scheduler {
-        using scheduler_concept = ::beman::execution::scheduler_t;
-
-        run_loop* loop;
-
-        auto schedule() noexcept -> sender { return {this->loop}; }
-        auto operator==(const scheduler&) const -> bool = default;
-    };
-
-    enum class state : unsigned char { starting, running, finishing };
-
-    state                     current_state{state::starting};
-    ::std::mutex              mutex{};
-    ::std::condition_variable condition{};
-    opstate_base*             front{};
-    opstate_base*             back{};
-
-    auto push_back(opstate_base* item) noexcept -> void {
-
-        ::std::lock_guard guard(this->mutex);
-        if (auto previous_back{::std::exchange(this->back, item)}) {
-            previous_back->next = item;
-        } else {
-            this->front = item;
-            this->condition.notify_one();
-        }
-    }
-    auto pop_front() noexcept -> opstate_base* {
-
-        ::std::unique_lock guard(this->mutex);
-        this->condition.wait(guard, [this] { return this->front || this->current_state == state::finishing; });
-        if (this->front == this->back)
-            this->back = nullptr;
-        return this->front ? ::std::exchange(this->front, this->front->next) : nullptr;
-    }
-#line 125 "include/beman/execution/detail/run_loop.hpp"
-  public:
-    run_loop() noexcept       = default;
-    run_loop(const run_loop&) = delete;
-    run_loop(run_loop&&)      = delete;
-    ~run_loop() {
-        ::std::lock_guard guard(this->mutex);
-        if (this->front != nullptr || this->current_state == state::running)
-            ::std::terminate();
-    }
-    auto operator=(const run_loop&) -> run_loop& = delete;
-    auto operator=(run_loop&&) -> run_loop&      = delete;
-
-    auto get_scheduler() -> scheduler { return {this}; }
-
-    auto run() -> void {
-        if (::std::lock_guard guard(this->mutex);
-            this->current_state != state::finishing &&
-            state::running == ::std::exchange(this->current_state, state::running)) {
-            ::std::terminate();
-        }
-#line 146 "include/beman/execution/detail/run_loop.hpp"
-        while (auto* op{this->pop_front()}) {
-            op->execute();
-        }
-    }
-    auto finish() -> void {
-        {
-            ::std::lock_guard guard(this->mutex);
-            this->current_state = state::finishing;
-        }
-        this->condition.notify_one();
-    }
-};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/get_completion_signatures.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_completion_signatures_t {
-  private:
-    template <typename Sender, typename Env>
-    static auto get(Sender&& sender, Env&& env) noexcept {
-        auto new_sender{[](auto&& sndr, auto&& e) -> decltype(auto) {
-            auto domain{::beman::execution::detail::get_domain_late(sndr, e)};
-            return ::beman::execution::transform_sender(domain, ::std::forward<Sender>(sndr), ::std::forward<Env>(e));
-        }};
-
-        using sender_type = ::std::remove_cvref_t<decltype(new_sender(sender, env))>;
-        using decayed_env = ::std::remove_cvref_t<Env>;
-        if constexpr (requires { new_sender(sender, env).get_completion_signatures(env); })
-            return decltype(new_sender(sender, env).get_completion_signatures(env)){};
-        else if constexpr (requires { typename sender_type::completion_signatures; })
-            return typename sender_type::completion_signatures{};
-        else if constexpr (::beman::execution::detail::
-                               is_awaitable<sender_type, ::beman::execution::detail::env_promise<decayed_env>>) {
-            using result_type =
-                ::beman::execution::detail::await_result_type<sender_type,
-                                                              ::beman::execution::detail::env_promise<decayed_env>>;
-            if constexpr (::std::same_as<void, result_type>) {
-                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(),
-                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
-                                                                 ::beman::execution::set_stopped_t()>{};
-            } else {
-                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(result_type),
-                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
-                                                                 ::beman::execution::set_stopped_t()>{};
-            }
-        }
-    }
-#line 55 "include/beman/execution/detail/get_completion_signatures.hpp"
-  public:
-    template <typename Sender, typename Env>
-        requires(!::std::same_as<void,
-                                 decltype(get_completion_signatures_t::get(::std::declval<Sender>(),
-                                                                           ::std::declval<Env>()))>)
-    auto operator()(Sender&& sender, Env&& env) const noexcept {
-        return this->get(::std::forward<Sender>(sender), ::std::forward<Env>(env));
-    }
-};
-export /* --------- */ inline constexpr get_completion_signatures_t get_completion_signatures{};
-} // namespace beman::execution
-
-#line 18 "include/beman/execution/detail/connect.hpp"
-namespace beman::execution::detail {
-
-#line 25 "include/beman/execution/detail/connect.hpp"
-export /* --------- */ struct connect_t {
-  private:
-    template <typename Sender, typename Receiver>
-    static auto make_new_sender(Sender&& sender, Receiver&& receiver)
-
-        noexcept(true) -> decltype(auto) {
-        return ::beman::execution::transform_sender(
-            decltype(::beman::execution::detail::get_domain_late(::std::forward<Sender>(sender),
-                                                                 ::beman::execution::get_env(receiver))){},
-            ::std::forward<Sender>(sender),
-            ::beman::execution::get_env(receiver));
-    }
-    template <typename Sender, typename Receiver>
-    static constexpr auto connect_noexcept() -> bool {
-        if constexpr (requires {
-                          make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>())
-                              .connect(::std::declval<Receiver>());
-                      }) {
-            return noexcept(make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>())
-                                .connect(::std::declval<Receiver>()));
-        } else if constexpr (requires {
-                                 ::beman::execution::detail::connect_awaitable(
-                                     make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>()),
-                                     ::std::declval<Receiver>());
-                             }) {
-            return noexcept(::beman::execution::detail::connect_awaitable(
-                make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>()), ::std::declval<Receiver>()));
-        }
-        return true;
-    }
-#line 56 "include/beman/execution/detail/connect.hpp"
-  public:
-    template <typename Sender, typename Receiver>
-    auto operator()(Sender&& sender, Receiver&& receiver) const noexcept(connect_noexcept<Sender, Receiver>()) {
-        auto new_sender = [&sender, &receiver]() -> decltype(auto) {
-            return make_new_sender(::std::forward<Sender>(sender), ::std::forward<Receiver>(receiver));
-        };
-
-        if constexpr (requires { new_sender().connect(::std::forward<Receiver>(receiver)); }) {
-            using state_type = decltype(new_sender().connect(::std::forward<Receiver>(receiver)));
-            static_assert(::beman::execution::operation_state<state_type>);
-            return new_sender().connect(::std::forward<Receiver>(receiver));
-        } else if constexpr (requires {
-                                 ::beman::execution::detail::connect_awaitable(new_sender(),
-                                                                               ::std::forward<Receiver>(receiver));
-                             }) {
-            return ::beman::execution::detail::connect_awaitable(new_sender(), ::std::forward<Receiver>(receiver));
-        } else {
-            enum bad_sender {};
-            static_assert(::std::same_as<bad_sender, decltype(new_sender())>,
-                          "result from transform_sender has no suitable connect()");
-        }
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-
-#line 86 "include/beman/execution/detail/connect.hpp"
-export /* --------- */ using connect_t = beman::execution::detail::connect_t;
-
-#line 95 "include/beman/execution/detail/connect.hpp"
-export /* --------- */ inline constexpr connect_t connect{};
-} // namespace beman::execution
-
-#line 16 "include/beman/execution/detail/sender_in.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
-concept sender_in =
-    ::beman::execution::sender<Sender> && ::beman::execution::detail::queryable<Env> &&
-    requires(Sender&& sender, Env&& env) {
-        {
-            ::beman::execution::get_completion_signatures(::std::forward<Sender>(sender), ::std::forward<Env>(env))
-        } -> ::beman::execution::detail::valid_completion_signatures;
-    };
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/connect_result_t.hpp"
-namespace beman::execution {
-
-#line 18 "include/beman/execution/detail/connect_result_t.hpp"
-export /* --------- */ template <typename Sender, typename Receiver>
-using connect_result_t = decltype(::beman::execution::connect(::std::declval<Sender>(), ::std::declval<Receiver>()));
-} // namespace beman::execution
-
-#line 29 "include/beman/execution/detail/stop_when.hpp"
-namespace beman::execution::detail {
-inline constexpr struct stop_when_t {
-    template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
-    struct sender;
-
-    template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
-    auto operator()(Sndr&& sndr, Tok&& tok) const noexcept;
-} stop_when{};
-} // namespace beman::execution::detail
-
-template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
-struct beman::execution::detail::stop_when_t::sender {
-    using sender_concept = ::beman::execution::sender_t;
-
-    stop_when_t               stop_when{};
-    std::remove_cvref_t<Tok>  tok;
-    std::remove_cvref_t<Sndr> sndr;
-
-    template <::beman::execution::receiver Rcvr>
-    struct state {
-        using operation_state_concept = ::beman::execution::operation_state_t;
-        using rcvr_t                  = ::std::remove_cvref_t<Rcvr>;
-        using token1_t                = ::std::remove_cvref_t<Tok>;
-        using token2_t =
-            decltype(::beman::execution::get_stop_token(::beman::execution::get_env(::std::declval<rcvr_t>())));
-
-        struct cb_t {
-            ::beman::execution::inplace_stop_source& source;
-            auto                                     operator()() const noexcept { this->source.request_stop(); }
-        };
-        struct base_state {
-            rcvr_t                                  rcvr;
-            ::beman::execution::inplace_stop_source source{};
-        };
-        struct env {
-            base_state* st;
-            auto        query(const ::beman::execution::get_stop_token_t&) const noexcept {
-                return this->st->source.get_token();
-            }
-            template <typename Q, typename... A>
-                requires requires(const Q& q, A&&... a, const rcvr_t& r) {
-                    q(::beman::execution::get_env(r), ::std::forward<A>(a)...);
-                }
-            auto query(const Q& q, A&&... a) const noexcept {
-                return q(::beman::execution::get_env(this->st->rcvr), ::std::forward<A>(a)...);
-            }
-        };
-
-        struct receiver {
-            using receiver_concept = ::beman::execution::receiver_t;
-            base_state* st;
-
-            auto get_env() const noexcept -> env { return env{this->st}; }
-            template <typename... A>
-            auto set_value(A&&... a) const noexcept -> void {
-                ::beman::execution::set_value(::std::move(this->st->rcvr), ::std::forward<A>(a)...);
-            }
-            template <typename E>
-            auto set_error(E&& e) const noexcept -> void {
-                ::beman::execution::set_error(::std::move(this->st->rcvr), ::std::forward<E>(e));
-            }
-            auto set_stopped() const noexcept -> void { ::beman::execution::set_stopped(::std::move(this->st->rcvr)); }
-        };
-        using inner_state_t =
-            decltype(::beman::execution::connect(::std::declval<Sndr>(), ::std::declval<receiver>()));
-
-        token1_t                                                               tok;
-        base_state                                                             base;
-        std::optional<::beman::execution::stop_callback_for_t<token1_t, cb_t>> cb1;
-        std::optional<::beman::execution::stop_callback_for_t<token2_t, cb_t>> cb2;
-        inner_state_t                                                          inner_state;
-
-        template <::beman::execution::sender S, ::beman::execution::stoppable_token T, ::beman::execution::receiver R>
-        state(S&& s, T&& t, R&& r)
-            : tok(::std::forward<T>(t)),
-              base{::std::forward<R>(r)},
-              inner_state(::beman::execution::connect(::std::forward<S>(s), receiver{&this->base})) {}
-
-        auto start() & noexcept {
-            this->cb1.emplace(this->tok, cb_t{this->base.source});
-            this->cb2.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(this->base.rcvr)),
-                              cb_t{this->base.source});
-            ::beman::execution::start(this->inner_state);
-        }
-    };
-
-    template <typename E>
-    auto get_completion_signatures(const E& e) const noexcept {
-        return ::beman::execution::get_completion_signatures(this->sndr, e);
-    }
-    template <::beman::execution::receiver Rcvr>
-    auto connect(Rcvr&& rcvr) && -> state<Rcvr> {
-        return state<Rcvr>{std::move(this->sndr), ::std::move(this->tok), ::std::forward<Rcvr>(rcvr)};
-    }
-};
-
-template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
-inline auto beman::execution::detail::stop_when_t::operator()(Sndr&& sndr, Tok&& tok) const noexcept {
-    if constexpr (::beman::execution::unstoppable_token<Tok>) {
-        return ::std::forward<Sndr>(sndr);
-    } else {
-        return sender<Sndr, Tok>{*this, ::std::forward<Tok>(tok), ::std::forward<Sndr>(sndr)};
-    }
-}
-#line 16 "include/beman/execution/detail/scope_token.hpp"
-namespace beman::execution::detail {
-struct token_test_env {};
-
-struct token_test_sender {
-    using sender_concept = ::beman::execution::sender_t;
-    template <typename... Env>
-    auto get_completion_signatures(const Env&...) const noexcept {
-        return ::beman::execution::completion_signatures<>{};
-    }
-};
-static_assert(::beman::execution::sender<::beman::execution::detail::token_test_sender>);
-static_assert(::beman::execution::sender_in<::beman::execution::detail::token_test_sender,
-                                            ::beman::execution::detail::token_test_env>);
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ template <typename Token>
-concept scope_token = ::std::copyable<Token> && requires(Token token) {
-    { token.try_associate() } -> ::std::same_as<bool>;
-    { token.disassociate() } noexcept;
-    {
-        token.wrap(::std::declval<::beman::execution::detail::token_test_sender>())
-    } -> ::beman::execution::sender_in<::beman::execution::detail::token_test_env>;
-};
-} // namespace beman::execution
-
-#line 16 "include/beman/execution/detail/completion_signatures_for.hpp"
-namespace beman::execution::detail {
-
-#line 22 "include/beman/execution/detail/completion_signatures_for.hpp"
-struct no_completion_signatures_defined_in_sender {};
-
-#line 29 "include/beman/execution/detail/completion_signatures_for.hpp"
-template <typename Sender, typename Env>
-struct completion_signatures_for_impl {
-    using type = ::beman::execution::detail::no_completion_signatures_defined_in_sender;
-};
-
-#line 39 "include/beman/execution/detail/completion_signatures_for.hpp"
-template <typename Sender, typename Env>
-using completion_signatures_for = ::std::conditional_t<
-    ::std::same_as<beman::execution::detail::no_completion_signatures_defined_in_sender,
-                   typename ::beman::execution::detail::completion_signatures_for_impl<Sender, Env>::type>,
-    typename ::beman::execution::detail::completion_signatures_for_impl<::std::remove_cvref_t<Sender>, Env>::type,
-    typename ::beman::execution::detail::completion_signatures_for_impl<Sender, Env>::type>;
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/completion_signatures_of_t.hpp"
-namespace beman::execution {
-
-#line 20 "include/beman/execution/detail/completion_signatures_of_t.hpp"
-export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
-    requires ::beman::execution::sender_in<Sender, Env>
-using completion_signatures_of_t =
-    ::beman::execution::detail::call_result_t<::beman::execution::get_completion_signatures_t, Sender, Env>;
-} // namespace beman::execution
-
-#line 23 "include/beman/execution/detail/connect_all.hpp"
-namespace beman::execution::detail {
-
-#line 29 "include/beman/execution/detail/connect_all.hpp"
-struct connect_all_t {
-  private:
-    template <typename Fun, typename Tuple, ::std::size_t... I>
-    static auto apply_with_index_helper(::std::index_sequence<I...> seq, Fun&& fun, Tuple&& tuple) noexcept(noexcept(
-        ::std::forward<Fun>(fun)(seq, ::beman::execution::detail::forward_like<Tuple>(::std::get<I>(tuple))...)))
-        -> decltype(auto) {
-        return ::std::forward<Fun>(fun)(seq, ::beman::execution::detail::forward_like<Tuple>(::std::get<I>(tuple))...);
-    }
-    template <typename Fun, typename Tuple>
-    static auto apply_with_index(Fun&& fun, Tuple&& tuple) noexcept(
-        noexcept(apply_with_index_helper(::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>>>{},
-                                         ::std::forward<Fun>(fun),
-                                         ::std::forward<Tuple>(tuple)))) -> decltype(auto) {
-        return apply_with_index_helper(::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>>>{},
-                                       ::std::forward<Fun>(fun),
-                                       ::std::forward<Tuple>(tuple));
-    }
-#line 47 "include/beman/execution/detail/connect_all.hpp"
-    template <::std::size_t Start, typename Fun, typename Tuple, ::std::size_t... I>
-    static auto sub_apply_with_index_helper(::std::index_sequence<I...> seq, Fun&& fun, Tuple&& tuple) noexcept(
-        noexcept(::std::forward<Fun>(fun)(
-            seq, ::beman::execution::detail::forward_like<Tuple>(tuple.template get<I + Start>())...)))
-        -> decltype(auto) {
-        return ::std::forward<Fun>(fun)(
-            seq, ::beman::execution::detail::forward_like<Tuple>(tuple.template get<I + Start>())...);
-    }
-    template <::std::size_t Start, typename Fun, typename Tuple>
-        requires requires { ::std::declval<Tuple>().size(); }
-    static auto sub_apply_with_index(Fun&& fun, Tuple&& tuple) noexcept(noexcept(sub_apply_with_index_helper<Start>(
-        ::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>> - Start>{},
-        ::std::forward<Fun>(fun),
-        ::std::forward<Tuple>(tuple)))) -> decltype(auto) {
-        return sub_apply_with_index_helper<Start>(
-            ::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>> - Start>{},
-            ::std::forward<Fun>(fun),
-            ::std::forward<Tuple>(tuple));
-    }
-    template <::std::size_t Start, typename Fun, typename Tuple>
-        requires(not requires { ::std::declval<Tuple>().size(); })
-    static auto
-    sub_apply_with_index(Fun&& fun,
-                         Tuple&&) noexcept(noexcept(::std::forward<Fun>(fun)(::std::make_index_sequence<0u>{}))) {
-        return ::std::forward<Fun>(fun)(::std::make_index_sequence<0u>{});
-    }
-#line 74 "include/beman/execution/detail/connect_all.hpp"
-    template <typename Sender, typename Receiver>
-    struct connect_helper {
-        ::beman::execution::detail::basic_state<Sender, Receiver>* op;
-
-        template <::std::size_t... J, typename... C>
-        auto operator()(::std::index_sequence<J...>, C&&... c) noexcept(
-            (noexcept(::beman::execution::connect(
-                 ::beman::execution::detail::forward_like<Sender>(c),
-                 ::beman::execution::detail::
-                     basic_receiver<Sender, Receiver, ::std::integral_constant<::std::size_t, J>>{this->op})) &&
-             ... && true)) -> decltype(auto) {
-            return ::beman::execution::detail::product_type{::beman::execution::connect(
-                ::beman::execution::detail::forward_like<Sender>(c),
-                ::beman::execution::detail::
-                    basic_receiver<Sender, Receiver, ::std::integral_constant<::std::size_t, J>>{this->op})...};
-        }
-    };
-
-    static auto use(auto&&...) {}
-
-  public:
-#line 96 "include/beman/execution/detail/connect_all.hpp"
-    template <typename Sender, typename S, typename Receiver, ::std::size_t... I>
-        requires requires(Sender&& s) {
-            s.size();
-            s.template get<0>();
-        }
-    auto operator()(::beman::execution::detail::basic_state<Sender, Receiver>* op,
-                    S&&                                                        sender,
-                    ::std::index_sequence<I...>) const
-        noexcept(noexcept(sub_apply_with_index<2>(connect_helper<Sender, Receiver>{op}, ::std::forward<S>(sender))))
-            -> decltype(auto) {
-        return sub_apply_with_index<2>(connect_helper<Sender, Receiver>{op}, ::std::forward<S>(sender));
-    }
-    template <typename Sender, typename S, typename Receiver, ::std::size_t... I>
-    auto operator()(::beman::execution::detail::basic_state<Sender, Receiver>* op,
-                    S&&                                                        sender,
-                    ::std::index_sequence<I...>) const
-        noexcept(noexcept(apply_with_index(
-            connect_helper<Sender, Receiver>{op},
-            ::beman::execution::detail::get_sender_data(::std::forward<S>(sender)).children))) -> decltype(auto) {
-        return apply_with_index(connect_helper<Sender, Receiver>{op},
-                                ::beman::execution::detail::get_sender_data(::std::forward<S>(sender)).children);
-    }
-};
-
-#line 126 "include/beman/execution/detail/connect_all.hpp"
-export /* --------- */ constexpr connect_all_t connect_all{};
-} // namespace beman::execution::detail
-
-#line 18 "include/beman/execution/detail/error_types_of_t.hpp"
-namespace beman::execution {
-
-#line 23 "include/beman/execution/detail/error_types_of_t.hpp"
-export /* --------- */ template <typename Sender,
-                                 typename Env                         = ::beman::execution::env<>,
-                                 template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
-    requires ::beman::execution::sender_in<Sender, Env>
-using error_types_of_t =
-    ::beman::execution::detail::gather_signatures<::beman::execution::set_error_t,
-                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
-                                                  ::std::type_identity_t,
-                                                  Variant>;
-} // namespace beman::execution
-
-#line 18 "include/beman/execution/detail/sends_stopped.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
-    requires ::beman::execution::sender_in<Sender, Env>
-inline constexpr bool sends_stopped{!::std::same_as<
-    ::beman::execution::detail::type_list<>,
-    ::beman::execution::detail::gather_signatures<::beman::execution::set_stopped_t,
-                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
-                                                  ::beman::execution::detail::type_list,
-                                                  ::beman::execution::detail::type_list>>};
-}
-#line 17 "include/beman/execution/detail/value_types_of_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Sender,
-                                 typename Env                         = ::beman::execution::env<>,
-                                 template <typename...> class Tuple   = ::beman::execution::detail::decayed_tuple,
-                                 template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
-    requires ::beman::execution::sender_in<Sender, Env>
-using value_types_of_t =
-    ::beman::execution::detail::gather_signatures<::beman::execution::set_value_t,
-                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
-                                                  Tuple,
-                                                  Variant>;
-}
-#line 15 "include/beman/execution/detail/connect_all_result.hpp"
-namespace beman::execution::detail {
-
-#line 21 "include/beman/execution/detail/connect_all_result.hpp"
-template <typename Sender, typename Receiver>
-using connect_all_result =
-    ::beman::execution::detail::call_result_t<decltype(::beman::execution::detail::connect_all),
-                                              ::beman::execution::detail::basic_state<Sender, Receiver>*,
-                                              Sender,
-                                              ::beman::execution::detail::indices_for<Sender>>;
-} // namespace beman::execution::detail
-
-#line 28 "include/beman/execution/detail/sync_wait.hpp"
-namespace beman::execution::detail {
-export /* --------- */ struct sync_wait_env {
-    ::beman::execution::run_loop* loop{};
-
-    auto query(::beman::execution::get_scheduler_t) const noexcept { return this->loop->get_scheduler(); }
-    auto query(::beman::execution::get_delegation_scheduler_t) const noexcept { return this->loop->get_scheduler(); }
-};
-
-export /* --------- */ template <::beman::execution::sender_in<::beman::execution::detail::sync_wait_env> Sender>
-using sync_wait_result_type =
-    ::std::optional<::beman::execution::value_types_of_t<Sender,
-                                                         ::beman::execution::detail::sync_wait_env,
-                                                         ::beman::execution::detail::decayed_tuple,
-                                                         ::std::type_identity_t>>;
-
-export /* --------- */ template <typename Sender>
-struct sync_wait_state {
-    ::beman::execution::run_loop loop{};
-    ::std::exception_ptr         error{};
-
-    ::beman::execution::detail::sync_wait_result_type<Sender> result{};
-};
-
-export /* --------- */ template <typename Sender>
-struct sync_wait_receiver {
-    using receiver_concept = ::beman::execution::receiver_t;
-
-    ::beman::execution::detail::sync_wait_state<Sender>* state{};
-
-    template <typename Error>
-    auto set_error(Error&& error) && noexcept -> void {
-        this->state->error = ::beman::execution::detail::as_except_ptr(::std::forward<Error>(error));
-        this->state->loop.finish();
-    }
-    auto set_stopped() && noexcept -> void { this->state->loop.finish(); }
-    template <typename... Args>
-    auto set_value(Args&&... args) && noexcept -> void {
-        try {
-            this->state->result.emplace(::std::forward<Args>(args)...);
-        } catch (...) {
-            this->state->error = ::std::current_exception();
-        }
-        this->state->loop.finish();
-    }
-#line 74 "include/beman/execution/detail/sync_wait.hpp"
-    auto get_env() const noexcept -> ::beman::execution::detail::sync_wait_env {
-        return ::beman::execution::detail::sync_wait_env{&this->state->loop};
-    }
-};
-
-struct sync_wait_t {
-    template <typename Sender>
-    auto apply_sender(Sender&& sender) const {
-        ::beman::execution::detail::sync_wait_state<Sender> state;
-        auto op{::beman::execution::connect(::std::forward<Sender>(sender),
-                                            ::beman::execution::detail::sync_wait_receiver<Sender>{&state})};
-        ::beman::execution::start(op);
-
-        state.loop.run();
-        if (state.error) {
-            ::std::rethrow_exception(state.error);
-        }
-        return ::std::move(state.result);
-    }
-#line 94 "include/beman/execution/detail/sync_wait.hpp"
-    template <::beman::execution::sender_in<::beman::execution::detail::sync_wait_env> Sender>
-        requires requires(Sender&& sender, const sync_wait_t& self) {
-            typename ::beman::execution::detail::sync_wait_result_type<Sender>;
-            {
-                ::beman::execution::apply_sender(
-                    ::beman::execution::detail::get_domain_early(std::forward<Sender>(sender)),
-                    self,
-                    ::std::forward<Sender>(sender))
-            } -> ::std::same_as<::beman::execution::detail::sync_wait_result_type<Sender>>;
-        }
-    auto operator()(Sender&& sender) const {
-        auto domain{::beman::execution::detail::get_domain_early(sender)};
-        return ::beman::execution::apply_sender(domain, *this, ::std::forward<Sender>(sender));
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using sync_wait_t = ::beman::execution::detail::sync_wait_t;
-
-#line 160 "include/beman/execution/detail/sync_wait.hpp"
-export /* --------- */ inline constexpr ::beman::execution::sync_wait_t sync_wait{};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/basic_operation.hpp"
-namespace beman::execution::detail {
-
-#line 29 "include/beman/execution/detail/basic_operation.hpp"
-export /* --------- */ template <typename Sender, typename Receiver>
-    requires ::beman::execution::detail::
-
-        valid_specialization<::beman::execution::detail::state_type, std::remove_cvref_t<Sender>, Receiver>
-    struct basic_operation : ::beman::execution::detail::basic_state<Sender, Receiver> {
-
-    friend struct ::beman::execution::start_t;
-    using operation_state_concept = ::beman::execution::operation_state_t;
-    using tag_t                   = ::beman::execution::tag_of_t<Sender>;
-
-    using inner_ops_t = ::beman::execution::detail::connect_all_result<Sender, Receiver>;
-    inner_ops_t inner_ops;
-
-    basic_operation(Sender&& sender, Receiver&& rcvr) noexcept(
-        noexcept(::beman::execution::detail::basic_state<Sender, Receiver>(::std::forward<Sender>(sender),
-                                                                           ::std::move(rcvr))) &&
-        noexcept(::beman::execution::detail::connect_all(this,
-                                                         ::std::forward<Sender>(sender),
-                                                         ::beman::execution::detail::indices_for<Sender>())))
-        : ::beman::execution::detail::basic_state<Sender, Receiver>(::std::forward<Sender>(sender), ::std::move(rcvr)),
-          // NOLINTBEGIN(bugprone-use-after-move,hicpp-invalid-access-moved)
-
-          inner_ops(::beman::execution::detail::connect_all(
-              this, ::std::forward<Sender>(sender), ::beman::execution::detail::indices_for<Sender>())) {}
-    // NOLINTEND(bugprone-use-after-move,hicpp-invalid-access-moved)
-
-  private:
-    auto start() & noexcept -> void {
-        ::std::invoke(
-            [this]<::std::size_t... I>(::std::index_sequence<I...>) {
-                ::beman::execution::detail::impls_for<tag_t>::start(
-                    this->state, this->receiver, this->inner_ops.template get<I>()...);
-            },
-            ::std::make_index_sequence<inner_ops_t::size()>{});
-    }
-};
-template <typename Sender, typename Receiver>
-basic_operation(Sender&&, Receiver&&) -> basic_operation<Sender&&, Receiver>;
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/single_sender_value_type.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Env>
-struct single_sender_value_type_helper;
-
-template <typename Sender, typename Env>
-    requires requires {
-        typename ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
-    }
-struct single_sender_value_type_helper<Sender, Env> {
-    using type = ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
-};
-
-template <typename Sender, typename Env>
-    requires ::std::same_as<::std::variant<::std::tuple<>>,
-                            ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>> ||
-             ::std::same_as<::std::variant<>,
-                            ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>>
-struct single_sender_value_type_helper<Sender, Env> {
-    using type = void;
-};
-
-template <typename Sender, typename Env>
-    requires(not requires {
-                typename ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
-            }) &&
-            (!::std::same_as<::std::variant<::std::tuple<>>,
-                             ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>>) &&
-            requires {
-                typename ::beman::execution::
-                    value_types_of_t<Sender, Env, ::beman::execution::detail::decayed_tuple, ::std::type_identity_t>;
-            }
-struct single_sender_value_type_helper<Sender, Env> {
-    using type = ::beman::execution::
-        value_types_of_t<Sender, Env, ::beman::execution::detail::decayed_tuple, ::std::type_identity_t>;
-};
-
-template <typename Sender, typename Env>
-using single_sender_value_type = typename single_sender_value_type_helper<Sender, Env>::type;
-} // namespace beman::execution::detail
-
-#line 23 "include/beman/execution/detail/basic_sender.hpp"
-namespace beman::execution::detail {
-
-#line 29 "include/beman/execution/detail/basic_sender.hpp"
-template <typename Tag, typename Data, typename... Child>
-struct basic_sender : ::beman::execution::detail::product_type<Tag, Data, Child...> {
-    friend struct ::beman::execution::detail::connect_t;
-    friend struct ::beman::execution::get_completion_signatures_t;
-    using sender_concept = ::beman::execution::sender_t;
-    using indices_for    = ::std::index_sequence_for<Child...>;
-
-    auto get_env() const noexcept -> decltype(auto) {
-        auto&& d{this->template get<1>()};
-        return sub_apply<2>(
-            [&d](auto&&... c) { return ::beman::execution::detail::impls_for<Tag>::get_attrs(d, c...); }, *this);
-    }
-#line 42 "include/beman/execution/detail/basic_sender.hpp"
-    template <typename Receiver>
-        requires(!::beman::execution::receiver<Receiver>)
-    auto connect(Receiver receiver) = BEMAN_EXECUTION_DELETE("the passed receiver doesn't model receiver");
-
-  private:
-#if __cpp_explicit_this_parameter < 302110L
-    template <::beman::execution::receiver Receiver>
-    auto connect(Receiver receiver) & noexcept(
-        noexcept(::beman::execution::detail::basic_operation<basic_sender&, Receiver>{*this, ::std::move(receiver)}))
-        -> ::beman::execution::detail::basic_operation<basic_sender&, Receiver> {
-        return {*this, ::std::move(receiver)};
-    }
-    template <::beman::execution::receiver Receiver>
-    auto connect(Receiver receiver) const& noexcept(noexcept(
-        ::beman::execution::detail::basic_operation<const basic_sender&, Receiver>{*this, ::std::move(receiver)}))
-        -> ::beman::execution::detail::basic_operation<const basic_sender&, Receiver> {
-        return {*this, ::std::move(receiver)};
-    }
-    template <::beman::execution::receiver Receiver>
-    auto connect(Receiver receiver) && noexcept(
-        noexcept(::beman::execution::detail::basic_operation<basic_sender, Receiver>{::std::move(*this),
-                                                                                     ::std::move(receiver)}))
-        -> ::beman::execution::detail::basic_operation<basic_sender, Receiver> {
-        return {::std::move(*this), ::std::move(receiver)};
-    }
-#else
-    template <::beman::execution::detail::decays_to<basic_sender> Self, ::beman::execution::receiver Receiver>
-    auto
-    connect(this Self&& self,
-            Receiver receiver) noexcept(noexcept(::beman::execution::detail::basic_operation<basic_sender, Receiver>{
-        ::std::forward<Self>(self), ::std::move(receiver)}))
-        -> ::beman::execution::detail::basic_operation<Self, Receiver> {
-        return {::std::forward<Self>(self), ::std::move(receiver)};
-    }
-#endif
-#if __cpp_explicit_this_parameter < 302110L
-    template <typename Env>
-    auto
-    get_completion_signatures(Env&&) && -> ::beman::execution::detail::completion_signatures_for<basic_sender, Env> {
-        return {};
-    }
-    template <typename Env>
-    auto get_completion_signatures(
-        Env&&) const&& -> ::beman::execution::detail::completion_signatures_for<const basic_sender, Env> {
-        return {};
-    }
-    template <typename Env>
-    auto
-    get_completion_signatures(Env&&) & -> ::beman::execution::detail::completion_signatures_for<basic_sender, Env> {
-        return {};
-    }
-    template <typename Env>
-    auto get_completion_signatures(
-        Env&&) const& -> ::beman::execution::detail::completion_signatures_for<const basic_sender, Env> {
-        return {};
-    }
-#else
-    template <::beman::execution::detail::decays_to<basic_sender> Self, typename Env>
-    auto get_completion_signatures(this Self&&, Env&&) noexcept
-        -> ::beman::execution::detail::completion_signatures_for<Self, Env> {
-        return {};
-    }
-#endif
-};
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/single_sender.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Env>
-concept single_sender = ::beman::execution::sender_in<Sender, Env> &&
-                        requires { typename ::beman::execution::detail::single_sender_value_type<Sender, Env>; };
-} // namespace beman::execution::detail
-
-#line 18 "include/beman/execution/detail/make_sender.hpp"
-namespace beman::execution::detail {
-struct make_sender_empty {};
-
-template <typename Tag, typename Data = ::beman::execution::detail::make_sender_empty, typename... Child>
-    requires ::std::semiregular<Tag> && ::beman::execution::detail::movable_value<Data> &&
-             (::beman::execution::sender<Child> && ...)
-constexpr auto make_sender(Tag tag, Data&& data, Child&&... child) {
-    return ::beman::execution::detail::basic_sender<Tag, ::std::decay_t<Data>, ::std::decay_t<Child>...>{
-        tag, ::std::forward<Data>(data), ::std::forward<Child>(child)...};
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/awaitable_sender.hpp"
-namespace beman::execution::detail {
-template <class Sndr, class Promise>
-concept awaitable_sender =
-    ::beman::execution::detail::single_sender<Sndr, ::beman::execution::env_of_t<Promise>> && requires(Promise& prom) {
-        { prom.unhandled_stopped() } -> ::std::convertible_to<::std::coroutine_handle<>>;
-    };
-} // namespace beman::execution::detail
-
-#line 29 "include/beman/execution/detail/sender_awaitable.hpp"
-namespace beman::execution::detail {
-template <class Sndr, class Promise>
-class sender_awaitable {
-    struct unit {};
-    using value_type =
-        ::beman::execution::detail::single_sender_value_type<Sndr, ::beman::execution::env_of_t<Promise>>;
-    using result_type  = ::std::conditional_t<::std::is_void_v<value_type>, unit, value_type>;
-    using variant_type = ::std::variant<::std::monostate, result_type, ::std::exception_ptr>;
-    using data_type    = ::std::tuple<variant_type, ::std::atomic<bool>, ::std::coroutine_handle<Promise>>;
-
-    struct awaitable_receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-
-        void resume() {
-            if (::std::get<1>(*result_ptr_).exchange(true, std::memory_order_acq_rel)) {
-                ::std::get<2>(*result_ptr_).resume();
-            }
-        }
-#line 48 "include/beman/execution/detail/sender_awaitable.hpp"
-        template <class... Args>
-            requires ::std::constructible_from<result_type, Args...>
-        void set_value(Args&&... args) && noexcept {
-            try {
-                ::std::get<0>(*result_ptr_).template emplace<1>(::std::forward<Args>(args)...);
-            } catch (...) {
-                ::std::get<0>(*result_ptr_).template emplace<2>(::std::current_exception());
-            }
-            this->resume();
-        }
-        template <class Error>
-        void set_error(Error&& error) && noexcept {
-            ::std::get<0>(*result_ptr_)
-                .template emplace<2>(::beman::execution::detail::as_except_ptr(::std::forward<Error>(error)));
-            this->resume();
-        }
-#line 65 "include/beman/execution/detail/sender_awaitable.hpp"
-        void set_stopped() && noexcept {
-            if (::std::get<1>(*result_ptr_).exchange(true, ::std::memory_order_acq_rel)) {
-                static_cast<::std::coroutine_handle<>>(::std::get<2>(*result_ptr_).promise().unhandled_stopped())
-                    .resume();
-            }
-        }
-#line 72 "include/beman/execution/detail/sender_awaitable.hpp"
-        auto get_env() const noexcept {
-            return ::beman::execution::detail::fwd_env{
-                ::beman::execution::get_env(::std::get<2>(*result_ptr_).promise())};
-        }
-#line 77 "include/beman/execution/detail/sender_awaitable.hpp"
-        data_type* result_ptr_;
-    };
-    using op_state_type = ::beman::execution::connect_result_t<Sndr, awaitable_receiver>;
-
-    data_type     result{};
-    op_state_type state;
-
-  public:
-    sender_awaitable(Sndr&& sndr, Promise& p)
-        : result{::std::monostate{}, false, ::std::coroutine_handle<Promise>::from_promise(p)},
-          state{::beman::execution::connect(::std::forward<Sndr>(sndr),
-                                            sender_awaitable::awaitable_receiver{::std::addressof(result)})} {}
-
-    static constexpr bool     await_ready() noexcept { return false; }
-    ::std::coroutine_handle<> await_suspend(::std::coroutine_handle<Promise> handle) noexcept {
-        ::beman::execution::start(state);
-        if (::std::get<1>(this->result).exchange(true, std::memory_order_acq_rel)) {
-            if (::std::holds_alternative<::std::monostate>(::std::get<0>(this->result))) {
-                return ::std::get<2>(this->result).promise().unhandled_stopped();
-            }
-            return ::std::move(handle);
-        }
-        return ::std::noop_coroutine();
-    }
-    value_type await_resume() {
-        if (::std::holds_alternative<::std::exception_ptr>(::std::get<0>(result))) {
-            ::std::rethrow_exception(::std::get<::std::exception_ptr>(::std::get<0>(result)));
-        }
-        if constexpr (::std::is_void_v<value_type>) {
-            return;
-        } else {
-            return ::std::get<value_type>(std::move(::std::get<0>(result)));
-        }
-    }
-};
-} // namespace beman::execution::detail
-
-#line 33 "include/beman/execution/detail/bulk.hpp"
-namespace beman::execution::detail {
-
-struct bulk_t : ::beman::execution::sender_adaptor_closure<bulk_t> {
-
-    template <class Shape, class f>
-        requires(std::is_integral_v<Shape> && ::beman::execution::detail::movable_value<f>)
-    auto operator()(Shape&& shape, f&& fun) const {
-        return beman::execution::detail::sender_adaptor{*this, std::forward<Shape>(shape), std::forward<f>(fun)};
-    }
-#line 43 "include/beman/execution/detail/bulk.hpp"
-    template <class Sender, class Shape, class f>
-        requires(::beman::execution::sender<Sender> && std::is_integral_v<Shape> &&
-                 ::beman::execution::detail::movable_value<f>)
-    auto operator()(Sender&& sndr, Shape&& shape, f&& fun) const {
-
-        auto domain{::beman::execution::detail::get_domain_early(sndr)};
-
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this, ::beman::execution::detail::product_type<Shape, f>{shape, fun}, std::forward<Sender>(sndr)));
-    }
-};
-
-template <>
-struct impls_for<bulk_t> : ::beman::execution::detail::default_impls {
-
-    static constexpr auto complete = []<class Index, class Shape, class Fun, class Rcvr, class Tag, class... Args>(
-                                         Index,
-                                         ::beman::execution::detail::product_type<Shape, Fun>& state,
-                                         Rcvr&                                                 rcvr,
-                                         Tag,
-                                         Args&&... args) noexcept -> void
-        requires(!::std::same_as<Tag, set_value_t> || std::is_invocable_v<Fun, Shape, Args...>)
-    {
-        if constexpr (std::same_as<Tag, set_value_t>) {
-            auto& [shape, f] = state;
-
-            using s_type = std::remove_cvref_t<decltype(shape)>;
-
-            constexpr bool nothrow = noexcept(f(s_type(shape), args...));
-
-            try {
-                [&]() noexcept(nothrow) {
-                    for (decltype(s_type(shape)) i = 0; i < shape; i++) {
-                        f(s_type(i), args...);
-                    }
-                    Tag()(std::move(rcvr), std::forward<Args>(args)...);
-                }();
-
-            } catch (...) {
-                if constexpr (not nothrow) {
-                    ::beman::execution::set_error(std::move(rcvr), std::current_exception());
-                }
-            }
-        } else {
-            Tag()(std::move(rcvr), std::forward<Args>(args)...);
-        }
-    };
-};
-
-template <typename, typename, typename>
-struct fixed_completions_helper;
-
-template <typename F, typename Shape, typename... Args>
-struct fixed_completions_helper<F, Shape, completion_signatures<Args...>> {
-
-    template <typename, typename>
-    struct may_throw;
-    template <typename XF, typename Tag, typename... XArgs>
-    struct may_throw<XF, Tag(XArgs...)> {
-        static constexpr bool value =
-            std::same_as<Tag, ::beman::execution::set_value_t> && !::std::is_nothrow_invocable<XF, Shape, XArgs...>();
-    };
-    template <typename XF, typename... Sigs>
-    struct may_throw<XF, completion_signatures<Sigs...>> {
-        static constexpr bool value = (false || ... || may_throw<XF, Sigs>::value);
-    };
-
-    using type = std::conditional_t<!may_throw<F, Args...>::value,
-                                    completion_signatures<Args...>,
-                                    completion_signatures<Args..., set_error_t(std::exception_ptr)>>;
-};
-
-template <typename F, typename Shape, typename Completions>
-using fixed_completions = typename fixed_completions_helper<F, Shape, Completions>::type;
-
-template <class Shape, class F, class Sender, class Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::
-        basic_sender<::beman::execution::detail::bulk_t, ::beman::execution::detail::product_type<Shape, F>, Sender>,
-    Env> {
-
-    using completions = decltype(get_completion_signatures(std::declval<Sender>(), std::declval<Env>()));
-    using type        = ::beman::execution::detail::meta::unique<
-               ::beman::execution::detail::meta::combine<fixed_completions<F, Shape, completions>>>;
-};
-
-} // namespace beman::execution::detail
-
-#line 135 "include/beman/execution/detail/bulk.hpp"
-namespace beman::execution {
-
-export /* --------- */ using bulk_t = ::beman::execution::detail::bulk_t;
-export /* --------- */ inline constexpr ::beman::execution::bulk_t bulk{};
-
-} // namespace beman::execution
-
-#line 32 "include/beman/execution/detail/into_variant.hpp"
-namespace beman::execution::detail {
-export /* --------- */ struct into_variant_t {
-    template <::beman::execution::sender Sender>
-    auto operator()(Sender&& sender) const {
-        auto domain{::beman::execution::detail::get_domain_early(sender)};
-        (void)domain;
-        return ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender));
-
-#line 43 "include/beman/execution/detail/into_variant.hpp"
-    }
-};
-
-template <>
-struct impls_for<::beman::execution::detail::into_variant_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_state = []<typename Sender, typename Receiver>(Sender&&, Receiver&&) noexcept
-        -> ::std::type_identity<::beman::execution::value_types_of_t<::beman::execution::detail::child_type<Sender>,
-                                                                     ::beman::execution::env_of_t<Receiver>>> {
-        return {};
-    };
-    static constexpr auto complete = []<typename State, typename Tag, typename... Args>(
-                                         auto, State, auto& receiver, Tag, Args&&... args) noexcept -> void {
-        if constexpr (::std::same_as<Tag, ::beman::execution::set_value_t>) {
-            using variant_type = typename State::type;
-            using tuple_type   = ::beman::execution::detail::decayed_tuple<Args...>;
-            try {
-                if constexpr (sizeof...(Args) == 0u)
-                    ::beman::execution::set_value(::std::move(receiver));
-                else
-                    ::beman::execution::set_value(::std::move(receiver),
-                                                  variant_type(tuple_type{::std::forward<Args>(args)...}));
-            } catch (...) {
-                ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-            }
-#line 68 "include/beman/execution/detail/into_variant.hpp"
-        } else {
-            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
-        }
-    };
-};
-
-template <typename Sender, typename State, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::into_variant_t, State, Sender>,
-    Env> {
-    using variant_type = ::beman::execution::value_types_of_t<Sender, Env>;
-    using value_types =
-        ::std::conditional_t<::std::same_as<variant_type, ::beman::execution::detail::empty_variant>,
-                             ::beman::execution::completion_signatures<>,
-                             ::beman::execution::completion_signatures<::beman::execution::set_value_t(variant_type)>>;
-    template <typename... E>
-    using make_error_types = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
-
-    using error_types = ::beman::execution::error_types_of_t<Sender, Env, make_error_types>;
-    using stopped_types =
-        ::std::conditional_t<::beman::execution::sends_stopped<Sender, Env>,
-                             ::beman::execution::completion_signatures<::beman::execution::set_stopped_t()>,
-                             ::beman::execution::completion_signatures<>>;
-    using type = ::beman::execution::detail::meta::
-        combine<value_types, ::beman::execution::detail::meta::combine<error_types, stopped_types>>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using into_variant_t = ::beman::execution::detail::into_variant_t;
-export /* --------- */ inline constexpr into_variant_t into_variant{};
-} // namespace beman::execution
-
-#line 25 "include/beman/execution/detail/just.hpp"
-namespace beman::execution::detail {
-template <typename Completion, typename... T>
-concept just_size = (!::std::same_as<Completion, ::beman::execution::set_error_t> or 1u == sizeof...(T)) &&
-                    (!::std::same_as<Completion, ::beman::execution::set_stopped_t> or 0u == sizeof...(T));
-template <typename Completion>
-struct just_t {
-    template <typename... T>
-        requires ::beman::execution::detail::just_size<Completion, T...> &&
-                 (::beman::execution::detail::movable_value<T> && ...)
-    auto operator()(T&&... arg) const {
-        return ::beman::execution::detail::make_sender(
-            *this, ::beman::execution::detail::product_type{::std::forward<T>(arg)...});
-    }
-    template <::beman::execution::sender Sender>
-    static auto affine_on(Sender&& sndr, const auto&) noexcept {
-        return ::std::forward<Sender>(sndr);
-    }
-};
-
-template <typename Completion, typename... T, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<just_t<Completion>, ::beman::execution::detail::product_type<T...>>,
-    Env> {
-    using type = ::beman::execution::completion_signatures<Completion(T...)>;
-};
-
-template <typename Completion>
-struct impls_for<just_t<Completion>> : ::beman::execution::detail::default_impls {
-    static constexpr auto start = []<typename State>(State& state, auto& receiver) noexcept -> void {
-        [&state, &receiver]<::std::size_t... I>(::std::index_sequence<I...>) {
-            Completion()(::std::move(receiver), ::std::move(state.template get<I>())...);
-        }(::std::make_index_sequence<State::size()>{});
-    };
-};
-} // namespace beman::execution::detail
-
-#line 63 "include/beman/execution/detail/just.hpp"
-namespace beman::execution {
-export /* --------- */ using just_t         = ::beman::execution::detail::just_t<::beman::execution::set_value_t>;
-export /* --------- */ using just_error_t   = ::beman::execution::detail::just_t<::beman::execution::set_error_t>;
-export /* --------- */ using just_stopped_t = ::beman::execution::detail::just_t<::beman::execution::set_stopped_t>;
-
-#line 117 "include/beman/execution/detail/just.hpp"
-export /* --------- */ inline constexpr ::beman::execution::just_t just{};
-
-#line 175 "include/beman/execution/detail/just.hpp"
-export /* --------- */ inline constexpr ::beman::execution::just_error_t just_error{};
-
-#line 229 "include/beman/execution/detail/just.hpp"
-export /* --------- */ inline constexpr ::beman::execution::just_stopped_t just_stopped{};
-} // namespace beman::execution
-
-#line 49 "include/beman/execution/detail/let.hpp"
-namespace beman::execution::detail {
-template <typename Completion>
-struct let_t {
-    template <::beman::execution::detail::movable_value Fun>
-    auto operator()(Fun&& fun) const {
-        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Fun>(fun)};
-    }
-    template <::beman::execution::sender Sender, ::beman::execution::detail::movable_value Fun>
-    auto operator()(Sender&& sender, Fun&& fun) const {
-        auto domain(::beman::execution::detail::get_domain_early(sender));
-        return ::beman::execution::detail::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(*this, ::std::forward<Fun>(fun), std::forward<Sender>(sender)));
-    }
-#line 64 "include/beman/execution/detail/let.hpp"
-    template <typename Sender>
-    static auto env(Sender&& sender) {
-        if constexpr (requires {
-                          ::beman::execution::detail::sched_env(
-                              ::beman::execution::get_completion_scheduler<Completion>(
-                                  ::beman::execution::get_env(sender)));
-                      })
-            return ::beman::execution::detail::sched_env(
-                ::beman::execution::get_completion_scheduler<Completion>(::beman::execution::get_env(sender)));
-        else if constexpr (requires {
-                               ::beman::execution::detail::make_env(
-                                   ::beman::execution::get_domain,
-                                   ::beman::execution::get_domain(::beman::execution::get_env(sender)));
-                           })
-            return ::beman::execution::detail::make_env(
-                ::beman::execution::get_domain, ::beman::execution::get_domain(::beman::execution::get_env(sender)));
-        else
-            return ::beman::execution::env<>{};
-    }
-    template <typename Sender, typename Env>
-    static auto join_env(Sender&& sender, Env&& e) -> decltype(auto) {
-        return ::beman::execution::detail::join_env(env(sender), ::beman::execution::detail::fwd_env(e));
-    }
-};
-
-template <typename Completion>
-struct impls_for<::beman::execution::detail::let_t<Completion>> : ::beman::execution::detail::default_impls {
-
-    template <typename Receiver, typename Env>
-    struct let_receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-
-        Receiver& receiver;
-        Env       env;
-
-        auto get_env() const noexcept -> decltype(auto) {
-            return ::beman::execution::detail::join_env(
-                this->env, ::beman::execution::detail::fwd_env(::beman::execution::get_env(this->receiver)));
-        }
-        template <typename Error>
-        auto set_error(Error&& error) && noexcept -> void {
-            ::beman::execution::set_error(::std::move(this->receiver), ::std::forward<Error>(error));
-        }
-        auto set_stopped() && noexcept -> void { ::beman::execution::set_stopped(::std::move(this->receiver)); }
-        template <typename... Args>
-        auto set_value(Args&&... args) && noexcept -> void {
-            ::beman::execution::set_value(::std::move(this->receiver), ::std::forward<Args>(args)...);
-        }
-    };
-
-    template <typename>
-    struct filter_pred : ::std::false_type {};
-    template <typename... A>
-    struct filter_pred<Completion(A...)> : ::std::true_type {};
-    template <typename>
-    struct to_tuple;
-    template <typename C, typename... A>
-    struct to_tuple<C(A...)> {
-        using type = ::beman::execution::detail::decayed_tuple<A...>;
-    };
-    template <typename T>
-    using to_tuple_t = typename to_tuple<T>::type;
-    template <typename Fun, typename Receiver, typename Env>
-    struct to_state {
-        template <typename Tuple>
-        using trans =
-            decltype(::beman::execution::connect(::std::apply(::std::declval<Fun>(), ::std::declval<Tuple>()),
-                                                 ::std::declval<let_receiver<Receiver, Env>>()));
-    };
-
-    static constexpr auto get_state{[]<typename Sender, typename Receiver>(Sender&& sender, Receiver&& receiver) {
-        auto& fun{sender.template get<1>()};
-        auto& child{sender.template get<2>()};
-
-        using fun_t   = ::std::remove_cvref_t<decltype(fun)>;
-        using child_t = ::std::remove_cvref_t<decltype(child)>;
-        using env_t   = decltype(::beman::execution::detail::let_t<Completion>::env(child));
-        using sigs_t = ::beman::execution::completion_signatures_of_t<child_t, ::beman::execution::env_of_t<Receiver>>;
-        using comp_sigs_t = ::beman::execution::detail::meta::filter<filter_pred, sigs_t>;
-        using type_list_t = ::beman::execution::detail::meta::to<::std::variant, comp_sigs_t>;
-        using tuples_t    = ::beman::execution::detail::meta::transform<to_tuple_t, type_list_t>;
-        using unique_t    = ::beman::execution::detail::meta::unique<tuples_t>;
-        using args_t      = ::beman::execution::detail::meta::prepend<std::monostate, unique_t>;
-        using ops_t       = ::beman::execution::detail::meta::prepend<
-                  ::std::monostate,
-                  ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::transform<
-                      to_state<fun_t, ::std::remove_cvref_t<Receiver>, env_t>::template trans,
-                      tuples_t>>>;
-
-        struct state_t {
-            fun_t  fun;
-            env_t  env;
-            args_t args;
-            ops_t  ops2;
-        };
-        return state_t{beman::execution::detail::allocator_aware_move(
-                           ::beman::execution::detail::forward_like<Sender>(fun), receiver),
-                       ::beman::execution::detail::let_t<Completion>::env(child),
-                       {},
-                       {}};
-    }};
-    template <typename Receiver, typename... Args>
-    static auto
-    let_bind(auto& state, Receiver& receiver, Args&&... args) noexcept(noexcept(::beman::execution::connect(
-        ::std::apply(::std::move(state.fun),
-                     ::std::move(state.args.template emplace<::beman::execution::detail::decayed_tuple<Args...>>(
-                         ::std::forward<Args>(args)...))),
-        let_receiver<Receiver, decltype(state.env)>{receiver, state.env}))) {
-        using args_t = ::beman::execution::detail::decayed_tuple<Args...>;
-        auto mkop{[&] {
-            return ::beman::execution::connect(
-                ::std::apply(::std::move(state.fun),
-                             ::std::move(state.args.template emplace<args_t>(::std::forward<Args>(args)...))),
-                let_receiver<Receiver, decltype(state.env)>{receiver, state.env});
-        }};
-        ::beman::execution::start(
-            state.ops2.template emplace<decltype(mkop())>(beman::execution::detail::emplace_from{mkop}));
-    }
-    static constexpr auto complete{
-        []<class Tag, class... Args>(auto, auto& state, auto& receiver, Tag, Args&&... args) {
-            if constexpr (::std::same_as<Tag, Completion>) {
-                try {
-                    let_bind(state, receiver, ::std::forward<Args>(args)...);
-                } catch (...) {
-                    if constexpr (not noexcept(let_bind(state, receiver, ::std::forward<Args>(args)...)))
-                        ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-                }
-            } else {
-                Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
-            }
-        }};
-};
-
-template <typename Completion, typename Fun, typename Sender, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::let_t<Completion>, Fun, Sender>,
-    Env> {
-    template <typename>
-    struct other_completion : ::std::true_type {};
-    template <typename... A>
-    struct other_completion<Completion(A...)> : ::std::false_type {};
-    template <typename>
-    struct matching_completion : ::std::false_type {};
-    template <typename... A>
-    struct matching_completion<Completion(A...)> : ::std::true_type {};
-
-    template <typename>
-    struct apply_decayed;
-    template <typename C, typename... A>
-    struct apply_decayed<C(A...)> {
-        using sender_type = ::beman::execution::detail::call_result_t<Fun, ::std::decay_t<A>...>;
-    };
-    template <typename>
-    struct get_completions;
-    template <template <typename...> class L, typename... C>
-    struct get_completions<L<C...>> {
-        using type = ::beman::execution::detail::meta::unique<
-            ::beman::execution::detail::meta::combine<decltype(::beman::execution::get_completion_signatures(
-                std::declval<typename apply_decayed<C>::sender_type>(), std::declval<Env>()))...>>;
-    };
-
-    using upstream_env = decltype(::beman::execution::detail::let_t<Completion>::join_env(::std::declval<Sender>(),
-                                                                                          ::std::declval<Env>()));
-    using upstream_completions = decltype(::beman::execution::get_completion_signatures(
-        ::std::declval<Sender>(), ::std::declval<upstream_env>()));
-    using other_completions    = ::beman::execution::detail::meta::filter<other_completion, upstream_completions>;
-    using matching_completions = ::beman::execution::detail::meta::filter<matching_completion, upstream_completions>;
-    using type = ::beman::execution::detail::meta::combine<typename get_completions<matching_completions>::type,
-                                                           other_completions>;
-};
-} // namespace beman::execution::detail
-
-#line 238 "include/beman/execution/detail/let.hpp"
-namespace beman::execution {
-export /* --------- */ using let_error_t   = ::beman::execution::detail::let_t<::beman::execution::set_error_t>;
-export /* --------- */ using let_stopped_t = ::beman::execution::detail::let_t<::beman::execution::set_stopped_t>;
-export /* --------- */ using let_value_t   = ::beman::execution::detail::let_t<::beman::execution::set_value_t>;
-
-export /* --------- */ inline constexpr ::beman::execution::let_error_t   let_error{};
-export /* --------- */ inline constexpr ::beman::execution::let_stopped_t let_stopped{};
-export /* --------- */ inline constexpr ::beman::execution::let_value_t   let_value{};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/read_env.hpp"
-namespace beman::execution::detail {
-struct read_env_t {
-    auto operator()(auto&& query) const { return ::beman::execution::detail::make_sender(*this, query); }
-    template <::beman::execution::sender Sender>
-    static auto affine_on(Sender&& sndr, const auto&) noexcept {
-        return ::std::forward<Sender>(sndr);
-    }
-};
-
-template <>
-struct impls_for<::beman::execution::detail::read_env_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto start = [](auto query, auto& receiver) noexcept -> void {
-        try {
-            auto env{::beman::execution::get_env(receiver)};
-            ::beman::execution::set_value(::std::move(receiver), query(env));
-        } catch (...) {
-            ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-        }
-    };
-};
-
-template <typename Query, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::read_env_t, Query>,
-    Env> {
-    using set_value_type =
-        ::beman::execution::set_value_t(decltype(::std::declval<Query>()(::std::as_const(::std::declval<Env>()))));
-    using set_error_type = ::beman::execution::set_error_t(::std::exception_ptr);
-    using type           = ::std::conditional_t<noexcept(::std::declval<Query>()(::std::declval<const Env&>())),
-                                                ::beman::execution::completion_signatures<set_value_type>,
-                                                ::beman::execution::completion_signatures<set_value_type, set_error_type>>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using read_env_t = beman::execution::detail::read_env_t;
-export /* --------- */ inline constexpr read_env_t read_env{};
-} // namespace beman::execution
-
-#line 47 "include/beman/execution/detail/schedule_from.hpp"
-namespace beman::execution::detail {
-struct schedule_from_t {
-    template <::beman::execution::scheduler Scheduler, ::beman::execution::sender Sender>
-    auto operator()(Scheduler&& scheduler, Sender&& sender) const {
-        auto domain{::beman::execution::detail::query_with_default(
-            ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{})};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this, ::std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
-    }
-};
-
-template <>
-struct impls_for<::beman::execution::detail::schedule_from_t> : ::beman::execution::detail::default_impls {
-    template <typename State>
-    struct upstream_receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-        State* state;
-
-        auto set_value() && noexcept -> void {
-            try {
-                ::std::visit(
-                    [this]<typename Tuple>(Tuple& result) noexcept -> void {
-                        if constexpr (!::std::same_as<::std::monostate, Tuple>) {
-                            ::std::apply(
-                                [this](auto&& tag, auto&&... args) {
-                                    tag(::std::move(this->state->receiver), ::std::move(args)...);
-                                },
-                                result);
-                        }
-                    },
-                    state->async_result);
-            } catch (...) {
-                ::beman::execution::set_error(::std::move(state->receiver), ::std::current_exception());
-            }
-        }
-#line 85 "include/beman/execution/detail/schedule_from.hpp"
-        template <typename Error>
-        auto set_error(Error&& err) && noexcept -> void {
-            ::beman::execution::set_error(std::move(state->receiver), std::forward<Error>(err));
-        }
-#line 90 "include/beman/execution/detail/schedule_from.hpp"
-        auto set_stopped() && noexcept -> void { ::beman::execution::set_stopped(std::move(state->receiver)); }
-
-        auto get_env() const noexcept -> decltype(auto) {
-            return ::beman::execution::detail::fwd_env(::beman::execution::get_env(state->receiver));
-        }
-    };
-    template <typename Receiver, typename Variant>
-    struct state_base {
-        Receiver receiver;
-        Variant  async_result{};
-    };
-    template <typename Receiver, typename Scheduler, typename Variant>
-    struct state_type : state_base<Receiver, Variant> {
-        using receiver_t = upstream_receiver<state_base<Receiver, Variant>>;
-        using operation_t =
-            ::beman::execution::connect_result_t<::beman::execution::schedule_result_t<Scheduler>, receiver_t>;
-        operation_t op_state;
-
-        static constexpr bool nothrow() {
-            return noexcept(::beman::execution::connect(::beman::execution::schedule(::std::declval<Scheduler>()),
-                                                        receiver_t{nullptr}));
-        }
-        explicit state_type(Scheduler& sch, Receiver& rcvr) noexcept(nothrow())
-            : state_base<Receiver, Variant>{rcvr},
-              op_state(::beman::execution::connect(::beman::execution::schedule(sch), receiver_t{this})) {}
-    };
-
-    static constexpr auto get_attrs{[](const auto& data, const auto& child) noexcept -> decltype(auto) {
-        return ::beman::execution::detail::join_env(
-            ::beman::execution::detail::sched_attrs(data),
-            ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
-    }};
-    static constexpr auto get_state{
-        []<typename Sender, typename Receiver>(Sender&& sender, Receiver& receiver)
-            requires ::beman::execution::sender_in<::beman::execution::detail::child_type<Sender>,
-                                                   ::beman::execution::env_of_t<Receiver>>
-        {
-            auto sch{sender.template get<1>()};
-
-            using sched_t   = ::std::remove_cvref_t<decltype(sch)>;
-            using variant_t = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
-                ::std::monostate,
-                ::beman::execution::detail::meta::transform<
-                    ::beman::execution::detail::as_tuple_t,
-                    ::beman::execution::detail::meta::to<::std::variant,
-                                                         ::beman::execution::detail::meta::combine<
-                                                             ::beman::execution::completion_signatures_of_t<
-                                                                 ::beman::execution::detail::child_type<Sender>,
-                                                                 ::beman::execution::env_of_t<Receiver>>,
-
-                                                             ::beman::execution::completion_signatures<
-                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
-                                                                 ::beman::execution::set_stopped_t()>>>>>>;
-
-            return state_type<Receiver, sched_t, variant_t>(sch, receiver);
-        }};
-    static constexpr auto complete{
-        []<typename Tag, typename... Args>(auto, auto& state, auto& receiver, Tag, Args&&... args) noexcept -> void {
-            using result_t         = ::beman::execution::detail::decayed_tuple<Tag, Args...>;
-            constexpr bool nothrow = ::std::is_nothrow_constructible_v<result_t, Tag, Args...>;
-
-            try {
-                [&]() noexcept(nothrow) {
-                    state.async_result.template emplace<result_t>(Tag(), std::forward<Args>(args)...);
-                }();
-            } catch (...) {
-                if constexpr (not nothrow)
-                    ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-            }
-#line 160 "include/beman/execution/detail/schedule_from.hpp"
-            if (state.async_result.index() == 0)
-                return;
-
-            ::beman::execution::start(state.op_state);
-        }};
-};
-
-template <typename Scheduler, typename Sender, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::schedule_from_t, Scheduler, Sender>,
-    Env> {
-    using scheduler_sender = decltype(::beman::execution::schedule(::std::declval<Scheduler>()));
-    template <typename... E>
-    using as_set_error = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
-    using type         = ::beman::execution::detail::meta::combine<
-                decltype(::beman::execution::get_completion_signatures(::std::declval<Sender>(), ::std::declval<Env>())),
-                ::beman::execution::error_types_of_t<scheduler_sender, Env, as_set_error>,
-                ::beman::execution::completion_signatures<::beman::execution::set_error_t(::std::exception_ptr)>>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using schedule_from_t = beman::execution::detail::schedule_from_t;
-export /* --------- */ inline constexpr ::beman::execution::schedule_from_t schedule_from{};
-} // namespace beman::execution
-
-#line 40 "include/beman/execution/detail/split.hpp"
-namespace beman::execution::detail {
-
-struct split_impl_t {};
-template <>
-struct impls_for<split_impl_t> : ::beman::execution::detail::default_impls {
-
-    template <class Sndr>
-    struct shared_state;
-
-    struct split_env {
-        ::beman::execution::inplace_stop_source* stop_source;
-
-        ::beman::execution::inplace_stop_token query(::beman::execution::get_stop_token_t) const noexcept {
-            return stop_source->get_token();
-        }
-    };
-
-    struct local_state_base {
-        local_state_base* next{nullptr};
-        virtual auto      notify() noexcept -> void = 0;
-
-        local_state_base() noexcept                                  = default;
-        local_state_base(const local_state_base&)                    = delete;
-        local_state_base(local_state_base&&)                         = delete;
-        auto operator=(const local_state_base&) -> local_state_base& = delete;
-        auto operator=(local_state_base&&) -> local_state_base&      = delete;
-
-      protected:
-        ~local_state_base() = default;
-    };
-
-    template <class Sndr>
-    struct split_receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-
-        explicit split_receiver(shared_state<Sndr>* state) noexcept : sh_state(state) {
-            if (sh_state) {
-                sh_state->inc_ref();
-            }
-        }
-#line 81 "include/beman/execution/detail/split.hpp"
-        ~split_receiver() noexcept {
-            if (sh_state) {
-                sh_state->dec_ref();
-            }
-        }
-#line 87 "include/beman/execution/detail/split.hpp"
-        split_receiver(split_receiver&& other) noexcept : sh_state(::std::exchange(other.sh_state, nullptr)) {}
-        split_receiver& operator=(split_receiver&& other) noexcept {
-            sh_state = ::std::exchange(other.sh_state, nullptr);
-            return *this;
-        }
-#line 93 "include/beman/execution/detail/split.hpp"
-        split_receiver(const split_receiver&)            = delete;
-        split_receiver& operator=(const split_receiver&) = delete;
-
-        template <class Tag, class... Args>
-        void complete(Tag, Args&&... args) noexcept {
-            using tuple_t = ::beman::execution::detail::decayed_tuple<Tag, Args...>;
-            try {
-                sh_state->result.template emplace<tuple_t>(Tag(), ::std::forward<Args>(args)...);
-            } catch (...) {
-                using tuple_err = ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>;
-                sh_state->result.template emplace<tuple_err>(::beman::execution::set_error,
-                                                             ::std::current_exception());
-            }
-            sh_state->notify();
-        }
-#line 109 "include/beman/execution/detail/split.hpp"
-        template <class... Args>
-        void set_value(Args&&... args) && noexcept {
-            complete(::beman::execution::set_value, ::std::forward<Args>(args)...);
-        }
-#line 114 "include/beman/execution/detail/split.hpp"
-        template <class Error>
-        void set_error(Error&& err) && noexcept {
-            complete(::beman::execution::set_error, ::std::forward<Error>(err));
-        }
-#line 119 "include/beman/execution/detail/split.hpp"
-        void set_stopped() && noexcept { complete(::beman::execution::set_stopped); }
-
-        split_env get_env() const noexcept { return split_env{&sh_state->stop_src}; }
-
-        shared_state<Sndr>* sh_state;
-    };
-
-#line 127 "include/beman/execution/detail/split.hpp"
-    template <class Sndr>
-    struct shared_state {
-        template <class... Args>
-        using value_tuple = ::std::tuple<::beman::execution::set_value_t, ::std::decay_t<Args>...>;
-
-        template <class... Args>
-        using error_tuples = ::std::variant<::std::tuple<::beman::execution::set_error_t, ::std::decay_t<Args>>...>;
-
-        using variant_type = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::combine<
-            ::std::variant<::std::monostate>,
-            ::std::variant<::std::tuple<::beman::execution::set_stopped_t>>,
-            ::std::variant<::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>>,
-            ::beman::execution::error_types_of_t<Sndr, split_env, error_tuples>,
-            ::beman::execution::value_types_of_t<Sndr, split_env, value_tuple>>>;
-
-        using state_list_type = ::beman::execution::detail::atomic_intrusive_stack<&local_state_base::next>;
-
-        using child_operation_state = ::beman::execution::connect_result_t<Sndr, split_receiver<Sndr>>;
-
-        explicit shared_state(Sndr&& sndr) {
-            try {
-                op_state.emplace(::beman::execution::detail::emplace_from{[&] {
-                    return ::beman::execution::connect(::std::forward<Sndr>(sndr), split_receiver<Sndr>{this});
-                }});
-            } catch (...) {
-                using error_tuple_t = ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>;
-                result.template emplace<error_tuple_t>(::beman::execution::set_error, ::std::current_exception());
-                [[maybe_unused]] auto queue = waiting_states.pop_all_and_shutdown();
-                assert(queue.empty());
-            }
-        }
-#line 163 "include/beman/execution/detail/split.hpp"
-        void add_listener(local_state_base* listener) noexcept {
-
-#line 166 "include/beman/execution/detail/split.hpp"
-            if (auto maybe_ptr = waiting_states.try_push(listener); !maybe_ptr) {
-
-                listener->notify();
-            } else if (!(*maybe_ptr)) {
-
-                assert(op_state);
-                if (op_state)
-                    ::beman::execution::start(*op_state);
-                else
-                    std::terminate();
-            }
-        }
-#line 179 "include/beman/execution/detail/split.hpp"
-        void notify() noexcept {
-
-#line 183 "include/beman/execution/detail/split.hpp"
-            op_state.reset();
-            auto listeners = waiting_states.pop_all_and_shutdown();
-            while (auto listener = listeners.pop()) {
-                listener->notify();
-            }
-        }
-#line 190 "include/beman/execution/detail/split.hpp"
-        void inc_ref() noexcept { ref_count.fetch_add(1); }
-
-#line 201 "include/beman/execution/detail/split.hpp"
-        void dec_ref() noexcept {
-            std::size_t count = ref_count.load();
-            if (count == 2 && waiting_states.empty_and_not_shutdown()) {
-                assert(op_state);
-                [[maybe_unused]] auto listeners = waiting_states.pop_all_and_shutdown();
-                assert(listeners.empty());
-                op_state.reset();
-            }
-            if (ref_count.fetch_sub(1) == 1) {
-                delete this;
-            }
-        }
-#line 214 "include/beman/execution/detail/split.hpp"
-        ::beman::execution::inplace_stop_source stop_src{};
-        variant_type                            result{};
-        state_list_type                         waiting_states{};
-        ::std::atomic<::std::size_t>            ref_count{0};
-        ::std::optional<child_operation_state>  op_state{};
-    };
-
-    template <class Sndr, class Receiver>
-    struct local_state final : local_state_base {
-        using stop_token_type = ::beman::execution::stop_token_of_t<::beman::execution::env_of_t<Receiver>>;
-
-        struct on_stop_type {
-            shared_state<Sndr>* sh_state;
-            void                operator()() noexcept { sh_state->stop_src.request_stop(); }
-        };
-
-        using on_stop_callback = ::beman::execution::stop_callback_for_t<stop_token_type, on_stop_type>;
-
-        explicit local_state(shared_state<Sndr>* state, Receiver& rcvr) noexcept
-            : sh_state(state), receiver{std::addressof(rcvr)} {
-            sh_state->inc_ref();
-        }
-#line 237 "include/beman/execution/detail/split.hpp"
-        ~local_state() noexcept { sh_state->dec_ref(); }
-
-        local_state(const local_state&)            = delete;
-        local_state& operator=(const local_state&) = delete;
-        local_state(local_state&&)                 = delete;
-        local_state& operator=(local_state&&)      = delete;
-
-        auto notify() noexcept -> void override {
-            on_stop.reset();
-            auto stop_token = ::beman::execution::get_stop_token(::beman::execution::get_env(receiver));
-            if (stop_token.stop_requested()) {
-                ::beman::execution::set_stopped(std::move(*receiver));
-            } else {
-                assert(sh_state->result.index() > 0);
-                assert(!sh_state->result.valueless_by_exception());
-                try {
-                    ::std::visit(
-                        [&]<class Arg>(const Arg& arg) noexcept -> void {
-                            if constexpr (!::std::same_as<::std::decay_t<Arg>, ::std::monostate>) {
-                                ::std::apply(
-                                    [&](auto tag, const auto&... args) noexcept -> void {
-                                        tag(::std::move(*receiver), args...);
-                                    },
-                                    arg);
-                            }
-                        },
-                        sh_state->result);
-                } catch (...) {
-
-#line 267 "include/beman/execution/detail/split.hpp"
-                    std::terminate();
-                }
-            }
-        }
-#line 272 "include/beman/execution/detail/split.hpp"
-        void start() noexcept {
-            on_stop.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(*receiver)),
-                            on_stop_type{sh_state});
-            sh_state->add_listener(this);
-        }
-#line 278 "include/beman/execution/detail/split.hpp"
-        std::optional<on_stop_callback> on_stop;
-        shared_state<Sndr>*             sh_state;
-        Receiver*                       receiver;
-    };
-
-    static constexpr auto get_state = []<typename Sender, typename Receiver>(Sender&&  sender,
-                                                                             Receiver& receiver) noexcept {
-        auto&& wrapper = sender.template get<1>();
-        return local_state(wrapper.sh_state, receiver);
-    };
-
-    static constexpr auto start = []<class Sndr, class Rcvr>(local_state<Sndr, Rcvr>& state, Rcvr&) noexcept {
-        state.start();
-    };
-};
-
-template <class Sndr>
-struct shared_wrapper {
-    explicit shared_wrapper(impls_for<split_impl_t>::shared_state<Sndr>* state) noexcept : sh_state(state) {
-        if (sh_state) {
-            sh_state->inc_ref();
-        }
-    }
-#line 302 "include/beman/execution/detail/split.hpp"
-    ~shared_wrapper() noexcept {
-        if (sh_state) {
-            sh_state->dec_ref();
-        }
-    }
-#line 308 "include/beman/execution/detail/split.hpp"
-    shared_wrapper(const shared_wrapper& other) noexcept : sh_state(other.sh_state) {
-        if (sh_state) {
-            sh_state->inc_ref();
-        }
-    }
-#line 314 "include/beman/execution/detail/split.hpp"
-    shared_wrapper(shared_wrapper&& other) noexcept : sh_state(::std::exchange(other.sh_state, nullptr)) {}
-
-    shared_wrapper& operator=(const shared_wrapper& other) noexcept {
-
-#line 319 "include/beman/execution/detail/split.hpp"
-        if (this == &other) {
-            return *this;
-        }
-        auto tmp = other;
-        ::std::swap(sh_state, tmp.sh_state);
-        return *this;
-    }
-#line 327 "include/beman/execution/detail/split.hpp"
-    shared_wrapper& operator=(shared_wrapper&& other) noexcept {
-        auto tmp = ::std::move(other);
-        ::std::swap(sh_state, tmp.sh_state);
-        return *this;
-    }
-#line 333 "include/beman/execution/detail/split.hpp"
-    impls_for<split_impl_t>::shared_state<Sndr>* sh_state;
-};
-
-struct split_t {
-    template <class Sndr>
-    auto transform_sender(Sndr&& sndr) const {
-        auto&& child       = ::std::forward<Sndr>(sndr).template get<2>();
-        using child_type   = decltype(child);
-        using shared_state = ::beman::execution::detail::impls_for<split_impl_t>::shared_state<child_type>;
-        auto* sh_state     = new shared_state{::beman::execution::detail::forward_like<Sndr>(child)};
-        return ::beman::execution::detail::make_sender(split_impl_t{}, shared_wrapper<child_type>{sh_state});
-    }
-#line 346 "include/beman/execution/detail/split.hpp"
-    template <class Sender>
-        requires beman::execution::sender_in<Sender, impls_for<split_impl_t>::split_env>
-    auto operator()(Sender&& sender) const {
-        auto domain{::beman::execution::detail::get_domain_early(sender)};
-        return ::beman::execution::transform_sender(
-            domain, ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)));
-    }
-};
-
-template <class Sndr, class Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::split_impl_t,
-                                             ::beman::execution::detail::shared_wrapper<Sndr>>,
-    Env> {
-    template <class... Args>
-    using make_value_completions =
-        ::beman::execution::completion_signatures<::beman::execution::set_value_t(const std::decay_t<Args>&...)>;
-
-    template <class... Args>
-    using make_error_completions =
-        ::beman::execution::completion_signatures<::beman::execution::set_error_t(const std::decay_t<Args>&)...>;
-
-    using value_completions = ::beman::execution::
-        value_types_of_t<Sndr, Env, make_value_completions, ::beman::execution::detail::meta::combine>;
-
-    using error_completions = ::beman::execution::error_types_of_t<Sndr, Env, make_error_completions>;
-
-    using fixed_completions =
-        ::beman::execution::completion_signatures<::beman::execution::set_stopped_t(),
-                                                  ::beman::execution::set_error_t(std::exception_ptr)>;
-
-    using type = ::beman::execution::detail::meta::unique<
-        ::beman::execution::detail::meta::combine<fixed_completions, value_completions, error_completions>>;
-};
-
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using split_t = ::beman::execution::detail::split_t;
-
-export /* --------- */ inline constexpr ::beman::execution::split_t split{};
-} // namespace beman::execution
-
-#line 37 "include/beman/execution/detail/then.hpp"
-namespace beman::execution::detail {
-template <typename Completion>
-struct then_t : ::beman::execution::sender_adaptor_closure<then_t<Completion>> {
-    template <::beman::execution::detail::movable_value Fun>
-    auto operator()(Fun&& fun) const {
-        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Fun>(fun)};
-    }
-    template <::beman::execution::sender Sender, ::beman::execution::detail::movable_value Fun>
-    auto operator()(Sender&& sender, Fun&& fun) const {
-        auto domain{::beman::execution::detail::get_domain_early(sender)};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(*this, ::std::forward<Fun>(fun), ::std::forward<Sender>(sender)));
-    }
-    template <::beman::execution::sender Sender, typename Env>
-        requires ::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>
-    static auto affine_on(Sender&& sndr, const Env&) noexcept {
-        return ::std::forward<Sender>(sndr);
-    }
-};
-
-template <typename Completion>
-struct impls_for<then_t<Completion>> : ::beman::execution::detail::default_impls {
-    // NOLINTBEGIN(bugprone-exception-escape)
-    static constexpr auto complete =
-        []<typename Tag, typename... Args>(auto, auto& fun, auto& receiver, Tag, Args&&... args) noexcept -> void {
-        if constexpr (::std::same_as<Completion, Tag>) {
-            try {
-                auto invoke = [&] { return ::std::invoke(::std::move(fun), ::std::forward<Args>(args)...); };
-                if constexpr (::std::same_as<void, decltype(invoke())>) {
-                    invoke();
-                    ::beman::execution::set_value(::std::move(receiver));
-                } else {
-                    ::beman::execution::set_value(::std::move(receiver), invoke());
-                }
-            } catch (...) {
-                if constexpr (not noexcept(::std::invoke(::std::move(fun), ::std::forward<Args>(args)...)
-
-                                               )) {
-                    static_assert(
-                        noexcept(::beman::execution::set_error(::std::move(receiver), ::std::current_exception())));
-                    ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-                }
-            }
-        } else {
-            static_assert(noexcept(Tag()(::std::move(receiver), ::std::forward<Args>(args)...)));
-            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
-        }
-    };
-    // NOLINTEND(bugprone-exception-escape)
-};
-
-template <typename T>
-struct then_set_value {
-    using type = ::beman::execution::set_value_t(T);
-};
-template <>
-struct then_set_value<void> {
-    using type = ::beman::execution::set_value_t();
-};
-
-template <typename, typename, typename Completion>
-struct then_transform {
-    using type = Completion;
-};
-
-template <typename Fun, typename Completion, typename... T>
-struct then_transform<Fun, Completion, Completion(T...)> {
-    using type = typename ::beman::execution::detail::then_set_value<
-        ::beman::execution::detail::call_result_t<Fun, T...>>::type;
-};
-
-template <typename Fun, typename Replace>
-struct then_transform_t {
-    template <typename Completion>
-    using transform = typename ::beman::execution::detail::then_transform<Fun, Replace, Completion>::type;
-};
-
-template <typename, typename, typename>
-struct then_exception_fun : ::std::false_type {};
-template <typename Comp, typename Fun, typename... A>
-struct then_exception_fun<Comp, Fun, Comp(A...)>
-    : ::std::bool_constant<not noexcept(::std::declval<Fun>()(::std::declval<A>()...))> {};
-
-template <typename, typename, typename>
-struct then_exception : ::std::false_type {};
-template <typename Comp, typename Fun, typename Completion, typename... Completions>
-struct then_exception<Comp, Fun, ::beman::execution::completion_signatures<Completion, Completions...>> {
-    static constexpr bool value{
-        then_exception_fun<Comp, Fun, Completion>::value ||
-        then_exception<Comp, Fun, ::beman::execution::completion_signatures<Completions...>>::value};
-};
-
-template <typename Completion, typename Fun, typename Sender, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::then_t<Completion>, Fun, Sender>,
-    Env> {
-    using type = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::combine<
-        ::beman::execution::detail::meta::transform<
-            ::beman::execution::detail::then_transform_t<Fun, Completion>::template transform,
-            ::beman::execution::completion_signatures_of_t<Sender, Env>>,
-        ::std::conditional_t<
-            ::beman::execution::detail::
-                then_exception<Completion, Fun, ::beman::execution::completion_signatures_of_t<Sender, Env>>::value,
-            ::beman::execution::completion_signatures<::beman::execution::set_error_t(::std::exception_ptr)>,
-            ::beman::execution::completion_signatures<>>>>;
-};
-} // namespace beman::execution::detail
-
-#line 148 "include/beman/execution/detail/then.hpp"
-namespace beman::execution {
-
-#line 153 "include/beman/execution/detail/then.hpp"
-export /* --------- */ using then_t = ::beman::execution::detail::then_t<::beman::execution::set_value_t>;
-
-#line 158 "include/beman/execution/detail/then.hpp"
-export /* --------- */ using upon_error_t = ::beman::execution::detail::then_t<::beman::execution::set_error_t>;
-
-#line 163 "include/beman/execution/detail/then.hpp"
-export /* --------- */ using upon_stopped_t = ::beman::execution::detail::then_t<::beman::execution::set_stopped_t>;
-
-#line 215 "include/beman/execution/detail/then.hpp"
-export /* --------- */ inline constexpr ::beman::execution::then_t then{};
-
-#line 269 "include/beman/execution/detail/then.hpp"
-export /* --------- */ inline constexpr ::beman::execution::upon_error_t upon_error{};
-
-#line 320 "include/beman/execution/detail/then.hpp"
-export /* --------- */ inline constexpr ::beman::execution::upon_stopped_t upon_stopped{};
-} // namespace beman::execution
-
-#line 51 "include/beman/execution/detail/when_all.hpp"
-namespace beman::execution::detail {
-struct when_all_t {
-    template <::beman::execution::sender... Sender>
-        requires(0u != sizeof...(Sender)) &&
-                ((::beman::execution::detail::meta::size_v<
-                      ::beman::execution::value_types_of_t<Sender,
-                                                           ::beman::execution::env<>,
-                                                           ::std::tuple,
-                                                           ::beman::execution::detail::type_list>> == 1u) &&
-                 ...) &&
-                requires(Sender&&... s) {
-                    typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(s))...>;
-                }
-    auto operator()(Sender&&... sender) const {
-        using common_t =
-            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
-        return ::beman::execution::transform_sender(
-            common_t(), ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)...));
-    }
-};
-
-template <typename>
-struct when_all_value_types;
-template <typename... T>
-struct when_all_value_types<::beman::execution::detail::type_list<T...>> {
-    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t(T...)>;
-};
-
-template <>
-struct impls_for<::beman::execution::detail::when_all_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_attrs{[](auto&&, auto&&... sender) {
-        using common_t =
-            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
-        if constexpr (::std::same_as<common_t, ::beman::execution::default_domain>)
-            return ::beman::execution::env<>{};
-        else
-            return ::beman::execution::detail::make_env(::beman::execution::get_domain, common_t{});
-    }};
-    static constexpr auto get_env{
-        []<typename State, typename Receiver>(auto&&, State& state, const Receiver& receiver) noexcept {
-            return ::beman::execution::detail::join_env(
-                ::beman::execution::detail::make_env(::beman::execution::get_stop_token, state.stop_src.get_token()),
-                ::beman::execution::get_env(receiver));
-        }};
-
-    enum class disposition : unsigned char { started, error, stopped };
-
-    template <typename Receiver, typename... Sender>
-    struct state_type {
-        struct nonesuch {};
-        using env_t        = ::beman::execution::env_of_t<Receiver>;
-        using values_tuple = ::std::tuple<
-            ::beman::execution::
-                value_types_of_t<Sender, env_t, ::beman::execution::detail::decayed_tuple, ::std::optional>...>;
-        using errors_variant = ::beman::execution::detail::meta::to<
-            ::std::variant,
-            ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
-                nonesuch,
-                ::beman::execution::detail::meta::prepend<
-                    ::std::exception_ptr,
-                    ::beman::execution::detail::meta::combine<::beman::execution::detail::meta::to<
-                        ::beman::execution::detail::type_list,
-                        ::beman::execution::detail::meta::combine<::beman::execution::error_types_of_t<
-                            Sender,
-                            env_t,
-                            ::beman::execution::detail::decayed_type_list>...>>>>>>>;
-        using stop_callback = ::beman::execution::stop_callback_for_t<
-            ::beman::execution::stop_token_of_t<::beman::execution::env_of_t<Receiver>>,
-            ::beman::execution::detail::on_stop_request<state_type>>;
-
-        void arrive(Receiver& recvr) noexcept {
-            if (0u == --count)
-                this->complete(recvr);
-        }
-#line 126 "include/beman/execution/detail/when_all.hpp"
-        void complete(Receiver& recvr) noexcept {
-            switch (disposition(this->disp)) {
-            case disposition::started: {
-                auto tie = []<typename... T>(::std::tuple<T...>& t) noexcept {
-                    return ::std::apply([](auto&... a) { return ::std::tie(a...); }, t);
-                };
-                auto set = [&](auto&... t) noexcept {
-                    ::beman::execution::set_value(::std::move(recvr), ::std::move(t)...);
-                };
-
-                this->on_stop.reset();
-                ::std::apply([&](auto&... opts) noexcept { ::std::apply(set, ::std::tuple_cat(tie(*opts)...)); },
-                             this->values);
-            } break;
-            case disposition::error:
-                this->on_stop.reset();
-                try {
-                    ::std::visit(
-                        [&]<typename Error>(Error& error) noexcept {
-                            if constexpr (!::std::same_as<Error, nonesuch>) {
-                                ::beman::execution::set_error(::std::move(recvr), ::std::move(error));
-                            }
-                        },
-                        this->errors);
-                } catch (...) {
-                    ::beman::execution::set_error(::std::move(recvr), ::std::current_exception());
-                }
-                break;
-            case disposition::stopped:
-                this->on_stop.reset();
-                ::beman::execution::set_stopped(::std::move(recvr));
-                break;
-            }
-        }
-#line 161 "include/beman/execution/detail/when_all.hpp"
-        auto request_stop() -> void {
-            if (1u == ++this->count)
-                --this->count;
-            else {
-                this->stop_src.request_stop();
-                this->arrive(*this->receiver);
-            }
-        }
-#line 170 "include/beman/execution/detail/when_all.hpp"
-        Receiver*                               receiver{};
-        ::std::atomic<::std::size_t>            count{sizeof...(Sender)};
-        ::beman::execution::inplace_stop_source stop_src{};
-        ::std::atomic<disposition>              disp{disposition::started};
-        errors_variant                          errors{};
-        values_tuple                            values{};
-        ::std::optional<stop_callback>          on_stop{::std::nullopt};
-    };
-
-    template <typename Receiver>
-    struct make_state {
-        template <::beman::execution::sender_in<::beman::execution::env_of_t<Receiver>>... Sender>
-        auto operator()(auto, auto, Sender&&...) const {
-            return state_type<Receiver, Sender...>{};
-        }
-    };
-    static constexpr auto get_state{[]<typename Sender, typename Receiver>(Sender&& sender, Receiver&) noexcept(
-                                        noexcept(std::forward<Sender>(sender).apply(make_state<Receiver>{}))) {
-        return std::forward<Sender>(sender).apply(make_state<Receiver>{});
-    }};
-    static constexpr auto start{[]<typename State, typename Receiver, typename... Ops>(
-                                    State& state, Receiver& receiver, Ops&... ops) noexcept -> void {
-        state.receiver = &receiver;
-        state.on_stop.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(receiver)),
-                              ::beman::execution::detail::on_stop_request{state});
-        if (state.stop_src.stop_requested()) {
-            state.on_stop.reset();
-            ::beman::execution::set_stopped(std::move(receiver));
-        } else {
-            (::beman::execution::start(ops), ...);
-        }
-    }};
-    static constexpr auto complete{
-        []<typename Index, typename State, typename Receiver, typename Set, typename... Args>(
-            Index, State& state, Receiver& receiver, Set, Args&&... args) noexcept -> void {
-            if constexpr (::std::same_as<Set, ::beman::execution::set_error_t>) {
-                if (disposition::error != state.disp.exchange(disposition::error)) {
-                    state.stop_src.request_stop();
-                    try {
-                        state.errors.template emplace<typename ::std::decay<Args...>::type>(
-                            ::std::forward<Args>(args)...);
-                    } catch (...) {
-                        state.errors.template emplace<::std::exception_ptr>(::std::current_exception());
-                    }
-                }
-            } else if constexpr (::std::same_as<Set, ::beman::execution::set_stopped_t>) {
-                auto expected = disposition::started;
-                if (state.disp.compare_exchange_strong(expected, disposition::stopped)) {
-                    state.stop_src.request_stop();
-                }
-            } else if constexpr (!::std::same_as<decltype(State::values), ::std::tuple<>>) {
-                if (state.disp == disposition::started) {
-                    auto& opt = ::std::get<Index::value>(state.values);
-                    try {
-                        opt.emplace(::std::forward<Args>(args)...);
-                    } catch (...) {
-                        if (disposition::error != state.disp.exchange(disposition::error)) {
-                            state.stop_src.request_stop();
-                            state.errors.template emplace<::std::exception_ptr>(::std::current_exception());
-                        }
-                    }
-                }
-            }
-            state.arrive(receiver);
-        }};
-};
-
-template <typename Data, typename Env, typename... Sender>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::when_all_t, Data, Sender...>,
-    Env> {
-    template <typename... E>
-    struct error_comps_t {
-        using type = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
-    };
-    template <typename... E>
-    using error_comps = typename error_comps_t<E...>::type;
-
-    using value_types =
-        typename ::beman::execution::detail::when_all_value_types<::beman::execution::detail::meta::combine<
-            ::beman::execution::
-                value_types_of_t<Sender, Env, ::beman::execution::detail::type_list, ::std::type_identity_t>...>>::
-            type;
-    using error_types = ::beman::execution::detail::meta::unique<
-        ::beman::execution::detail::meta::combine<::beman::execution::error_types_of_t<Sender, Env, error_comps>...>>;
-    using stopped_types =
-        ::std::conditional_t<(false || ... || ::beman::execution::sends_stopped<Sender, Env>),
-                             ::beman::execution::completion_signatures<::beman::execution::set_stopped_t()>,
-                             ::beman::execution::completion_signatures<>>;
-    using type = ::beman::execution::detail::meta::combine<value_types, error_types, stopped_types>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using when_all_t = ::beman::execution::detail::when_all_t;
-export /* --------- */ inline constexpr ::beman::execution::when_all_t when_all{};
-} // namespace beman::execution
-
-#line 21 "include/beman/execution/detail/write_env.hpp"
-namespace beman::execution::detail {
-struct write_env_t {
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
-    constexpr auto operator()(Sender&& sender, Env&& env) const {
-        return ::beman::execution::detail::make_sender(
-            *this, ::std::forward<Env>(env), ::std::forward<Sender>(sender));
-    }
-    static auto name() { return "write_env_t"; }
-    template <::beman::execution::sender Sender, typename Env>
-        requires ::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>
-    static auto affine_on(Sender&& sndr, const Env&) noexcept {
-        return ::std::forward<Sender>(sndr);
-    }
-};
-
-template <typename NewEnv, typename Child, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::write_env_t, NewEnv, Child>,
-    Env> {
-    using type = decltype(::beman::execution::get_completion_signatures(
-        ::std::declval<Child>(),
-        ::beman::execution::detail::join_env(::std::declval<NewEnv>(), ::std::declval<Env>())));
-};
-
-template <>
-struct impls_for<write_env_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_env = [](auto, const auto& state, const auto& receiver) noexcept {
-        return ::beman::execution::detail::join_env(state, ::beman::execution::get_env(receiver));
-    };
-};
-
-inline constexpr write_env_t write_env{};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using write_env_t = ::beman::execution::detail::write_env_t;
-export /* --------- */ inline constexpr write_env_t write_env{};
-} // namespace beman::execution
-
-#line 23 "include/beman/execution/detail/associate.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <::beman::execution::scope_token Token, ::beman::execution::sender Sender>
-struct associate_data {
-    using wrap_sender = ::std::remove_cvref_t<decltype(::std::declval<Token&>().wrap(::std::declval<Sender>()))>;
-
-    explicit associate_data(Token t, Sender&& s) : token(t), sender(this->token.wrap(::std::forward<Sender>(s))) {
-        if (!token.try_associate()) {
-            this->sender.reset();
-        }
-    }
-    associate_data(const associate_data& other) noexcept(::std::is_nothrow_copy_constructible_v<wrap_sender> &&
-                                                         noexcept(token.try_associate()))
-        : token(other.token), sender() {
-        if (other.sender && this->token.try_associate()) {
-            try {
-                this->sender.emplace(*other.sender);
-            } catch (...) {
-                this->token.disassociate();
-            }
-        }
-    }
-    associate_data(associate_data&& other) noexcept(::std::is_nothrow_move_constructible_v<wrap_sender>)
-        : token(other.token), sender(::std::move(other.sender)) {
-        other.sender.reset();
-    }
-    auto operator=(const associate_data&) -> associate_data& = delete;
-    auto operator=(associate_data&&) -> associate_data&      = delete;
-    ~associate_data() {
-        if (this->sender) {
-            this->sender.reset();
-            this->token.disassociate();
-        }
-    }
-#line 58 "include/beman/execution/detail/associate.hpp"
-    auto release() -> ::std::optional<::std::pair<Token, wrap_sender>> {
-        return this->sender ? (std::unique_ptr<std::optional<wrap_sender>, decltype([](auto* opt) { opt->reset(); })>(
-                                   &this->sender),
-                               ::std::optional{::std::pair{::std::move(this->token), ::std::move(*this->sender)}})
-                            : ::std::optional<::std::pair<Token, wrap_sender>>{};
-    }
-#line 65 "include/beman/execution/detail/associate.hpp"
-    Token                        token;
-    ::std::optional<wrap_sender> sender;
-};
-export /* --------- */ template <::beman::execution::scope_token Token, ::beman::execution::sender Sender>
-associate_data(Token, Sender&&) -> associate_data<Token, Sender>;
-
-struct associate_t {
-    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token>
-    auto operator()(Sender&& sender, Token&& token) const {
-        auto domain(::beman::execution::detail::get_domain_early(sender));
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this,
-                ::beman::execution::detail::associate_data(::std::forward<Token>(token),
-                                                           ::std::forward<Sender>(sender))));
-    }
-};
-
-template <>
-struct impls_for<associate_t> : ::beman::execution::detail::default_impls {
-    template <typename, typename>
-    struct get_noexcept : ::std::false_type {};
-    template <typename Tag, typename Data, typename Receiver>
-    struct get_noexcept<::beman::execution::detail::basic_sender<Tag, Data>, Receiver>
-        : ::std::bool_constant<
-              ::std::is_nothrow_move_constructible_v<typename ::std::remove_cvref_t<Data>::wrap_sender>&& ::beman::
-                  execution::detail::nothrow_callable<::beman::execution::connect_t,
-                                                      typename ::std::remove_cvref_t<Data>::wrap_sender,
-                                                      Receiver>> {};
-
-    static constexpr auto get_state =
-        []<typename Sender, typename Receiver>(Sender&& sender, Receiver& receiver) noexcept(
-            ::std::is_nothrow_constructible_v<::std::remove_cvref_t<Sender>, Sender>&&
-                get_noexcept<::std::remove_cvref_t<Sender>, Receiver>::value) {
-            auto [_, data] = ::std::forward<Sender>(sender);
-            auto dataParts{data.release()};
-
-            using scope_token = decltype(dataParts->first);
-            using wrap_sender = decltype(dataParts->second);
-            using op_t        = decltype(::beman::execution::connect(::std::move(dataParts->second),
-                                                              ::std::forward<Receiver>(receiver)));
-
-            struct op_state {
-                using sop_t        = op_t;
-                using sscope_token = scope_token;
-                struct assoc_t {
-                    sscope_token tok;
-                    sop_t        op;
-                };
-
-                bool associated{false};
-                union {
-                    Receiver* rcvr;
-                    assoc_t   assoc;
-                };
-                explicit op_state(Receiver& r) noexcept : rcvr(::std::addressof(r)) {}
-                explicit op_state(sscope_token tk, wrap_sender&& sndr, Receiver& r) try
-                    : associated(true), assoc(tk, ::beman::execution::connect(::std::move(sndr), ::std::move(r))) {
-                } catch (...) {
-                    tk.disassociate();
-                    throw;
-                }
-                op_state(op_state&&) = delete;
-                ~op_state() {
-                    if (this->associated) {
-                        this->assoc.op.~sop_t();
-                        this->assoc.tok.disassociate();
-                        this->assoc.tok.~sscope_token();
-                    }
-                }
-                auto run() noexcept -> void {
-                    if (this->associated) {
-                        ::beman::execution::start(this->assoc.op);
-                    } else {
-                        ::beman::execution::set_stopped(::std::move(*this->rcvr));
-                    }
-                }
-            };
-            return dataParts ? op_state(::std::move(dataParts->first), ::std::move(dataParts->second), receiver)
-                             : op_state(receiver);
-        };
-    static constexpr auto start = [](auto& state, auto&&) noexcept -> void { state.run(); };
-};
-
-template <typename Data, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::associate_t, Data>,
-    Env> {
-    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t()>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using associate_t = ::beman::execution::detail::associate_t;
-export /* --------- */ inline constexpr associate_t associate{};
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/as_awaitable.hpp"
-namespace beman::execution {
-
-#line 24 "include/beman/execution/detail/as_awaitable.hpp"
-export /* --------- */ struct as_awaitable_t {
-    template <typename Expr, typename Promise>
-    auto operator()(Expr&& expr, Promise& promise) const {
-        if constexpr (requires { ::std::forward<Expr>(expr).as_awaitable(promise); }) {
-            static_assert(
-                ::beman::execution::detail::is_awaitable<decltype(::std::forward<Expr>(expr).as_awaitable(promise)),
-                                                         Promise>,
-                "as_awaitable must return an awaitable");
-            return ::std::forward<Expr>(expr).as_awaitable(promise);
-        } else if constexpr (::beman::execution::detail::
-                                 is_awaitable<Expr, ::beman::execution::detail::unspecified_promise> ||
-                             !::beman::execution::detail::awaitable_sender<Expr, Promise>) {
-            return ::std::forward<Expr>(expr);
-        } else {
-            return ::beman::execution::detail::sender_awaitable<Expr, Promise>{::std::forward<Expr>(expr), promise};
-        }
-    }
-};
-export /* --------- */ inline constexpr ::beman::execution::as_awaitable_t as_awaitable{};
-} // namespace beman::execution
-
-#line 26 "include/beman/execution/detail/counting_scope_join.hpp"
-namespace beman::execution::detail {
-struct counting_scope_join_t {
-    template <::beman::execution::receiver>
-    struct state;
-
-    auto operator()(::beman::execution::detail::counting_scope_base* ptr) const {
-        return ::beman::execution::detail::make_sender(*this, ptr);
-    }
-};
-inline constexpr counting_scope_join_t counting_scope_join{};
-
-template <typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::counting_scope_join_t,
-                                             ::beman::execution::detail::counting_scope_base*>,
-    Env> {
-    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t()>;
-};
-
-} // namespace beman::execution::detail
-
-#line 49 "include/beman/execution/detail/counting_scope_join.hpp"
-template <::beman::execution::receiver Receiver>
-struct beman::execution::detail::counting_scope_join_t::state : ::beman::execution::detail::counting_scope_base::node {
-    using op_t = decltype(::beman::execution::connect(::beman::execution::schedule(::beman::execution::get_scheduler(
-                                                          ::beman::execution::get_env(::std::declval<Receiver&>()))),
-                                                      ::std::declval<Receiver&>()));
-
-    ::beman::execution::detail::counting_scope_base* scope;
-    explicit state(::beman::execution::detail::counting_scope_base* s, Receiver& r)
-        : scope(s),
-          receiver(r),
-          op(::beman::execution::connect(::beman::execution::schedule(::beman::execution::get_scheduler(
-                                             ::beman::execution::get_env(this->receiver))),
-                                         this->receiver)) {}
-    virtual ~state() = default;
-
-    auto complete() noexcept -> void override { ::beman::execution::start(this->op); }
-    auto complete_inline() noexcept -> void override { ::beman::execution::set_value(::std::move(this->receiver)); }
-
-    auto start() noexcept -> void { this->scope->start_node(this); }
-
-    ::std::remove_cvref_t<Receiver>& receiver;
-    op_t                             op;
-};
-
-#line 75 "include/beman/execution/detail/counting_scope_join.hpp"
-namespace beman::execution::detail {
-template <>
-struct impls_for<::beman::execution::detail::counting_scope_join_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_state = []<typename Receiver>(auto&& sender, Receiver& receiver) noexcept(false) {
-        auto [_, self] = sender;
-        return ::beman::execution::detail::counting_scope_join_t::state<Receiver>(self, receiver);
-    };
-    static constexpr auto start = [](auto& s, auto&) noexcept { s.start(); };
-};
-} // namespace beman::execution::detail
-
-#line 36 "include/beman/execution/detail/affine_on.hpp"
-namespace beman::execution::detail {
-template <typename Ev>
-struct affine_on_env {
-    Ev   ev_;
-    auto query(const ::beman::execution::get_stop_token_t&) const noexcept -> ::beman::execution::never_stop_token {
-        return ::beman::execution::never_stop_token();
-    }
-    template <typename Q>
-    auto query(const Q& q) const noexcept -> decltype(q(this->ev_)) {
-        return q(this->ev_);
-    }
-};
-template <typename Ev>
-affine_on_env(const Ev&) -> affine_on_env<Ev>;
-
-#line 59 "include/beman/execution/detail/affine_on.hpp"
-struct affine_on_t : ::beman::execution::sender_adaptor_closure<affine_on_t> {
-
-#line 67 "include/beman/execution/detail/affine_on.hpp"
-    template <::beman::execution::sender Sender>
-    auto operator()(Sender&& sender) const {
-        return ::beman::execution::detail::transform_sender(
-            ::beman::execution::detail::get_domain_early(sender),
-            ::beman::execution::detail::make_sender(
-                *this, ::beman::execution::env<>{}, ::std::forward<Sender>(sender)));
-    }
-#line 80 "include/beman/execution/detail/affine_on.hpp"
-    auto operator()() const { return ::beman::execution::detail::sender_adaptor{*this}; }
-
-#line 100 "include/beman/execution/detail/affine_on.hpp"
-    template <::beman::execution::sender Sender, typename Env>
-        requires ::beman::execution::detail::sender_for<Sender, affine_on_t> && requires(const Env& env) {
-            { ::beman::execution::get_scheduler(env) } -> ::beman::execution::scheduler;
-            { ::beman::execution::schedule(::beman::execution::get_scheduler(env)) } -> ::beman::execution::sender;
-            {
-                ::beman::execution::get_completion_signatures(
-                    ::beman::execution::schedule(::beman::execution::get_scheduler(env)),
-                    ::beman::execution::detail::join_env(
-                        ::beman::execution::env{::beman::execution::prop{
-                            ::beman::execution::get_stop_token, ::beman::execution::never_stop_token{}, {}}},
-                        env))
-            } -> ::std::same_as<::beman::execution::completion_signatures<::beman::execution::set_value_t()>>;
-        }
-    static auto transform_sender(Sender&& sender, const Env& ev) {
-        [[maybe_unused]] auto& [tag, data, child] = sender;
-        using child_tag_t = ::beman::execution::tag_of_t<::std::remove_cvref_t<decltype(child)>>;
-
-        if constexpr (::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>) {
-            constexpr child_tag_t t{};
-            return t.affine_on(::beman::execution::detail::forward_like<Sender>(child), ev);
-        } else {
-            return ::beman::execution::write_env(
-                ::beman::execution::schedule_from(
-                    ::beman::execution::get_scheduler(ev),
-                    ::beman::execution::write_env(::beman::execution::detail::forward_like<Sender>(child), ev)),
-                beman::execution::detail::affine_on_env(ev));
-        }
-    }
-};
-
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-
-#line 137 "include/beman/execution/detail/affine_on.hpp"
-export /* --------- */ using affine_on_t = beman::execution::detail::affine_on_t;
-export /* --------- */ inline constexpr affine_on_t affine_on{};
-} // namespace beman::execution
-
-#line 32 "include/beman/execution/detail/continues_on.hpp"
-namespace beman::execution::detail {
-
-#line 39 "include/beman/execution/detail/continues_on.hpp"
-struct continues_on_t {
-    template <::beman::execution::detail::sender_for<continues_on_t> Sender, typename... Env>
-    static auto transform_sender(Sender&& sender, Env&&...) {
-        auto&& data{sender.template get<1>()};
-        auto&& child{sender.template get<2>()};
-        return ::beman::execution::schedule_from(std::move(data), std::move(child));
-    }
-    template <::beman::execution::scheduler Scheduler>
-    auto operator()(Scheduler&& scheduler) const {
-        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Scheduler>(scheduler)};
-    }
-    template <::beman::execution::sender Sender, ::beman::execution::scheduler Scheduler>
-    auto operator()(Sender&& sender, Scheduler&& scheduler) const {
-        auto domain(::beman::execution::detail::get_domain_early(sender));
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this, std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
-    }
-};
-
-#line 65 "include/beman/execution/detail/continues_on.hpp"
-template <>
-struct impls_for<::beman::execution::detail::continues_on_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_attrs{[](const auto& data, const auto& child) noexcept -> decltype(auto) {
-        return ::beman::execution::detail::join_env(
-            ::beman::execution::detail::sched_attrs(data),
-            ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
-    }};
-};
-
-#line 79 "include/beman/execution/detail/continues_on.hpp"
-template <::beman::execution::detail::sender_for<::beman::execution::detail::continues_on_t> Sender, typename Env>
-auto get_domain_late(Sender&& sender, Env&&) {
-    auto scheduler{sender.template get<1>()};
-    return ::beman::execution::detail::query_with_default(
-        ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{});
-}
-} // namespace beman::execution::detail
-
-#line 89 "include/beman/execution/detail/continues_on.hpp"
-namespace beman::execution {
-export /* --------- */ using continues_on_t = ::beman::execution::detail::continues_on_t;
-
-#line 95 "include/beman/execution/detail/continues_on.hpp"
-export /* --------- */ inline constexpr continues_on_t continues_on{};
-} // namespace beman::execution
-
-#line 26 "include/beman/execution/detail/starts_on.hpp"
-namespace beman::execution::detail {
-struct starts_on_t {
-    template <::beman::execution::detail::sender_for<::beman::execution::detail::starts_on_t> Sender, typename Env>
-    auto transform_env(Sender&& sender, Env&& env) const noexcept {
-        auto&& scheduler{sender.template get<1>()};
-        return ::beman::execution::detail::join_env(::beman::execution::detail::sched_env(scheduler),
-                                                    ::beman::execution::detail::fwd_env(env));
-    }
-    template <::beman::execution::detail::sender_for<::beman::execution::detail::starts_on_t> Sender, typename... Env>
-    auto transform_sender(Sender&& sender, Env&&...) const noexcept {
-        auto&& scheduler{sender.template get<1>()};
-        auto&& new_sender{sender.template get<2>()};
-        return ::beman::execution::let_value(
-            ::beman::execution::schedule(scheduler),
-            [new_sender = ::beman::execution::detail::forward_like<Sender>(new_sender)]() mutable noexcept(
-                ::std::is_nothrow_constructible_v<::std::decay_t<Sender>>) { return ::std::move(new_sender); });
-    }
-#line 44 "include/beman/execution/detail/starts_on.hpp"
-    template <::beman::execution::scheduler Scheduler, ::beman::execution::sender Sender>
-    auto operator()(Scheduler&& scheduler, Sender&& sender) const {
-        auto domain{::beman::execution::detail::query_with_default(
-            ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{})};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this, ::std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using starts_on_t = ::beman::execution::detail::starts_on_t;
-export /* --------- */ inline constexpr ::beman::execution::detail::starts_on_t starts_on{};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/when_all_with_variant.hpp"
-namespace beman::execution::detail {
-struct when_all_with_variant_t {
-
-    template <::beman::execution::sender Sender>
-    auto transform_sender(Sender&& sender, auto&&...) const noexcept {
-        return ::std::forward<Sender>(sender).apply([](auto&&, auto&&, auto&&... child) {
-            return ::beman::execution::when_all(
-                ::beman::execution::into_variant(::beman::execution::detail::forward_like<Sender>(child))...);
-        });
-    }
-#line 33 "include/beman/execution/detail/when_all_with_variant.hpp"
-    template <::beman::execution::sender... Sender>
-    auto operator()(Sender&&... sender) const {
-        using domain_t =
-            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
-        return ::beman::execution::transform_sender(
-            domain_t{}, ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)...));
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using when_all_with_variant_t = ::beman::execution::detail::when_all_with_variant_t;
-export /* --------- */ inline constexpr ::beman::execution::when_all_with_variant_t when_all_with_variant{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/with_awaitable_senders.hpp"
-namespace beman::execution {
-export /* --------- */ template <::beman::execution::detail::class_type Promise>
-struct with_awaitable_senders {
-    template <class OtherPromise>
-        requires(!::std::same_as<OtherPromise, void>)
-    void set_continuation(::std::coroutine_handle<OtherPromise> h) noexcept {
-        contination_ = h;
-        if constexpr (requires(OtherPromise& other) { other.unhandled_stopped(); }) {
-            stopped_handler_ = [](void* p) noexcept -> ::std::coroutine_handle<> {
-                return ::std::coroutine_handle<OtherPromise>::from_address(p).promise().unhandled_stopped();
-            };
-        } else {
-            stopped_handler_ = &default_unhandled_stopped;
-        }
-    }
-#line 30 "include/beman/execution/detail/with_awaitable_senders.hpp"
-    ::std::coroutine_handle<> continuation() const noexcept { return contination_; }
-
-    ::std::coroutine_handle<> unhandled_stopped() noexcept { return stopped_handler_(contination_.address()); }
-
-    template <class Value>
-    auto await_transform(Value&& value)
-        -> ::beman::execution::detail::call_result_t<::beman::execution::as_awaitable_t, Value, Promise&> {
-        return ::beman::execution::as_awaitable(::std::forward<Value>(value), static_cast<Promise&>(*this));
-    }
-#line 40 "include/beman/execution/detail/with_awaitable_senders.hpp"
-  private:
-    friend Promise;
-    with_awaitable_senders() = default;
-
-    [[noreturn]] static auto default_unhandled_stopped(void*) noexcept -> ::std::coroutine_handle<> {
-        ::std::terminate();
-    }
-#line 48 "include/beman/execution/detail/with_awaitable_senders.hpp"
-    ::std::coroutine_handle<> contination_{};
-    ::std::coroutine_handle<> (*stopped_handler_)(void*) noexcept = &default_unhandled_stopped;
-};
-
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/counting_scope.hpp"
-namespace beman::execution {
-export /* --------- */ class counting_scope;
-}
-#line 25 "include/beman/execution/detail/counting_scope.hpp"
-class beman::execution::counting_scope : public ::beman::execution::detail::counting_scope_base {
-  public:
-    class token;
-
-    auto join() noexcept -> ::beman::execution::sender auto {
-        return ::beman::execution::detail::counting_scope_join(this);
-    }
-    auto get_token() noexcept -> token;
-    auto request_stop() noexcept -> void { this->stop_source.request_stop(); }
-
-  private:
-    ::beman::execution::inplace_stop_source stop_source{};
-};
-
-#line 41 "include/beman/execution/detail/counting_scope.hpp"
-class beman::execution::counting_scope::token : public ::beman::execution::detail::counting_scope_base::token {
-  public:
-    template <::beman::execution::sender Sender>
-    auto wrap(Sender&& sender) const noexcept -> ::beman::execution::sender auto {
-        return ::beman::execution::detail::stop_when(
-            ::std::forward<Sender>(sender),
-            static_cast<::beman::execution::counting_scope*>(this->scope)->stop_source.get_token());
-    }
-#line 50 "include/beman/execution/detail/counting_scope.hpp"
-  private:
-    friend class beman::execution::counting_scope;
-    explicit token(::beman::execution::counting_scope* s)
-        : ::beman::execution::detail::counting_scope_base::token(s) {}
-};
-static_assert(::beman::execution::scope_token<::beman::execution::counting_scope::token>);
-
-#line 59 "include/beman/execution/detail/counting_scope.hpp"
-inline auto beman::execution::counting_scope::get_token() noexcept -> beman::execution::counting_scope::token {
-    return beman::execution::counting_scope::token(this);
-}
-#line 16 "include/beman/execution/detail/simple_counting_scope.hpp"
-namespace beman::execution {
-export /* --------- */ class simple_counting_scope;
-}
-#line 22 "include/beman/execution/detail/simple_counting_scope.hpp"
-class beman::execution::simple_counting_scope : public ::beman::execution::detail::counting_scope_base {
-  public:
-    class token;
-
-    auto get_token() noexcept -> token;
-    auto join() noexcept -> ::beman::execution::sender auto {
-        return ::beman::execution::detail::counting_scope_join(this);
-    }
-};
-
-#line 34 "include/beman/execution/detail/simple_counting_scope.hpp"
-class beman::execution::simple_counting_scope::token : public ::beman::execution::detail::counting_scope_base::token {
-  public:
-    template <::beman::execution::sender Sender>
-    auto wrap(Sender&& sender) const noexcept -> Sender&& {
-        return ::std::forward<Sender>(sender);
-    }
-#line 41 "include/beman/execution/detail/simple_counting_scope.hpp"
-  private:
-    friend class beman::execution::simple_counting_scope;
-    explicit token(::beman::execution::detail::counting_scope_base* s)
-        : ::beman::execution::detail::counting_scope_base::token(s) {}
-};
-
-#line 49 "include/beman/execution/detail/simple_counting_scope.hpp"
-inline auto beman::execution::simple_counting_scope::get_token() noexcept
-    -> beman::execution::simple_counting_scope::token {
-    return beman::execution::simple_counting_scope::token(this);
-}
-#line 44 "include/beman/execution/detail/spawn_future.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct non_throwing_args_copy;
-template <typename Rc, typename... A>
-struct non_throwing_args_copy<Rc(A...)> {
-    static constexpr bool value = (true && ... && ::std::is_nothrow_constructible_v<::std::decay_t<A>, A>);
-};
-template <typename S>
-inline constexpr bool non_throwing_args_copy_v{non_throwing_args_copy<S>::value};
-
-template <typename Completions>
-struct spawn_future_state_base;
-template <typename... Sigs>
-struct spawn_future_state_base<::beman::execution::completion_signatures<Sigs...>> {
-    static constexpr bool has_non_throwing_args_copy = (true && ... && non_throwing_args_copy_v<Sigs>);
-    using result_t                                   = ::beman::execution::detail::meta::unique<
-                                          ::std::conditional_t<has_non_throwing_args_copy,
-                                                               ::std::variant<::std::monostate, ::beman::execution::detail::as_tuple_t<Sigs>...>,
-                                                               ::std::variant<::std::monostate,
-                                                                              ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>,
-                                                                              ::beman::execution::detail::as_tuple_t<Sigs>...>>>;
-
-    result_t result{};
-    virtual ~spawn_future_state_base()       = default;
-    virtual auto complete() noexcept -> void = 0;
-};
-
-template <typename Completions>
-struct spawn_future_receiver {
-    using receiver_concept = ::beman::execution::receiver_t;
-    using state_t          = ::beman::execution::detail::spawn_future_state_base<Completions>;
-
-    state_t* state{};
-
-    template <typename... A>
-    auto set_value(A&&... a) && noexcept -> void {
-        this->set_complete<::beman::execution::set_value_t>(::std::forward<A>(a)...);
-    }
-    template <typename E>
-    auto set_error(E&& e) && noexcept -> void {
-        this->set_complete<::beman::execution::set_error_t>(::std::forward<E>(e));
-    }
-    auto set_stopped() && noexcept -> void { this->set_complete<::beman::execution::set_stopped_t>(); }
-
-    template <typename Tag, typename... T>
-    auto set_complete(T&&... t) noexcept {
-        try {
-            this->state->result.template emplace<::beman::execution::detail::decayed_tuple<Tag, T...>>(
-                Tag(), ::std::forward<T>(t)...);
-        } catch (...) {
-            if constexpr (!state_t::has_non_throwing_args_copy) {
-                this->state->result
-                    .template emplace<::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>>(
-                        ::beman::execution::set_error_t{}, ::std::current_exception());
-            }
-        }
-        this->state->complete();
-    }
-};
-
-template <::beman::execution::sender Sndr, typename Env>
-using future_spawned_sender = decltype(::beman::execution::write_env(
-    ::beman::execution::detail::stop_when(::std::declval<Sndr>(),
-                                          ::std::declval<::beman::execution::inplace_stop_token>()),
-    ::std::declval<Env>()));
-
-template <::beman::execution::sender Sndr, typename Env>
-using spawn_future_sigs = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
-    ::beman::execution::set_stopped_t(),
-    ::beman::execution::completion_signatures_of_t<::beman::execution::detail::future_spawned_sender<Sndr, Env>>>>;
-
-template <typename Allocator, ::beman::execution::scope_token Token, ::beman::execution::sender Sndr, typename Env>
-struct spawn_future_state
-    : ::beman::execution::detail::spawn_future_state_base<::beman::execution::detail::spawn_future_sigs<Sndr, Env>> {
-    using alloc_t          = typename ::std::allocator_traits<Allocator>::template rebind_alloc<spawn_future_state>;
-    using traits_t         = ::std::allocator_traits<alloc_t>;
-    using spawned_sender_t = ::beman::execution::detail::future_spawned_sender<Sndr, Env>;
-    using sigs_t           = ::beman::execution::detail::spawn_future_sigs<Sndr, Env>;
-    using receiver_t       = ::beman::execution::detail::spawn_future_receiver<sigs_t>;
-    static_assert(::beman::execution::sender<spawned_sender_t>);
-    static_assert(::beman::execution::receiver<receiver_t>);
-    using op_t = ::beman::execution::connect_result_t<spawned_sender_t, receiver_t>;
-
-    template <::beman::execution::sender S>
-    spawn_future_state(auto a, S&& s, Token tok, Env env)
-        : alloc(::std::move(a)),
-          op(::beman::execution::write_env(
-                 ::beman::execution::detail::stop_when(::std::forward<S>(s), source.get_token()), env),
-             receiver_t{this}),
-          token(::std::move(tok)),
-          associated(token.try_associate()) {
-        if (this->associated) {
-            ::beman::execution::start(this->op);
-        } else {
-            ::beman::execution::set_stopped(receiver_t{this});
-        }
-    }
-    auto complete() noexcept -> void override {
-        {
-            ::std::lock_guard cerberos(this->gate);
-            if (this->fun == nullptr) {
-                this->receiver = this;
-                return;
-            }
-        }
-        this->fun(this->receiver, *this);
-    }
-    auto abandon() noexcept -> void {
-        bool ready{[&] {
-            ::std::lock_guard cerberos(this->gate);
-            if (this->receiver == nullptr) {
-                this->receiver = this;
-                this->fun      = [](void*, spawn_future_state& state) noexcept { state.destroy(); };
-                return false;
-            }
-            return true;
-        }()};
-        if (ready) {
-            this->destroy();
-        } else {
-            this->source.request_stop();
-        }
-    }
-    template <::beman::execution::receiver Rcvr>
-    static auto complete_receiver(Rcvr& rcvr, typename spawn_future_state::result_t& res) noexcept {
-        std::visit(
-            [&rcvr]<typename Tuplish>(Tuplish&& tuplish) noexcept {
-                if constexpr (!::std::same_as<::std::remove_cvref_t<decltype(tuplish)>, ::std::monostate>) {
-                    ::std::apply(
-                        [&rcvr]<typename... Args>(auto cpo, Args&&... args) {
-                            cpo(::std::move(rcvr), ::std::forward<Args>(args)...);
-                        },
-                        ::std::forward<Tuplish>(tuplish));
-                }
-            },
-            ::std::move(res));
-    }
-    template <::beman::execution::receiver Rcvr>
-    auto consume(Rcvr& rcvr) noexcept -> void {
-        {
-            ::std::lock_guard cerberos(this->gate);
-            if (this->receiver == nullptr) {
-                this->receiver = &rcvr;
-                this->fun      = [](void* ptr, spawn_future_state& state) noexcept {
-                    spawn_future_state::complete_receiver(*static_cast<Rcvr*>(ptr), state.result);
-                };
-                return;
-            }
-        }
-        spawn_future_state::complete_receiver(rcvr, this->result);
-    }
-    auto destroy() noexcept -> void {
-        Token tok{this->token};
-        bool  assoc{this->associated};
-        {
-            alloc_t a{this->alloc};
-            traits_t::destroy(a, this);
-            traits_t::deallocate(a, this, 1u);
-        }
-        if (assoc) {
-            tok.disassociate();
-        }
-    }
-#line 208 "include/beman/execution/detail/spawn_future.hpp"
-    ::std::mutex                            gate{};
-    alloc_t                                 alloc;
-    ::beman::execution::inplace_stop_source source{};
-    op_t                                    op;
-    Token                                   token;
-    bool                                    associated{false};
-    void*                                   receiver{};
-    auto (*fun)(void*, spawn_future_state&) noexcept -> void = nullptr;
-};
-
-class spawn_future_t {
-  public:
-    template <::beman::execution::sender Sndr, ::beman::execution::scope_token Tok, typename Ev>
-        requires ::beman::execution::detail::queryable<::std::remove_cvref_t<Ev>>
-    auto operator()(Sndr&& sndr, Tok&& tok, Ev&& ev) const {
-
-        auto make{[&]() -> decltype(auto) { return tok.wrap(::std::forward<Sndr>(sndr)); }};
-        using sndr_t = decltype(make());
-        static_assert(::beman::execution::sender<Sndr>);
-
-        auto [alloc, senv] = spawn_get_allocator(sndr, ev);
-        using state_t = ::beman::execution::detail::spawn_future_state<decltype(alloc), Tok, sndr_t, decltype(senv)>;
-        using state_alloc_t  = typename ::std::allocator_traits<decltype(alloc)>::template rebind_alloc<state_t>;
-        using state_traits_t = ::std::allocator_traits<state_alloc_t>;
-        state_alloc_t state_alloc(alloc);
-        state_t*      op{state_traits_t::allocate(state_alloc, 1u)};
-        try {
-            state_traits_t::construct(state_alloc, op, alloc, make(), tok, senv);
-        } catch (...) {
-            state_traits_t::deallocate(state_alloc, op, 1u);
-            throw;
-        }
-#line 241 "include/beman/execution/detail/spawn_future.hpp"
-        using deleter = decltype([](state_t* p) noexcept { p->abandon(); });
-        return ::beman::execution::detail::make_sender(*this, ::std::unique_ptr<state_t, deleter>{op});
-    }
-    template <::beman::execution::sender Sndr, ::beman::execution::scope_token Tok>
-    auto operator()(Sndr&& sndr, Tok&& tok) const {
-        return (*this)(::std::forward<Sndr>(sndr), ::std::forward<Tok>(tok), ::beman::execution::env<>{});
-    }
-};
-
-template <typename State, typename Deleter, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::spawn_future_t,
-                                             ::std::unique_ptr<State, Deleter>>,
-    Env> {
-    using type = typename State::sigs_t;
-};
-
-template <>
-struct impls_for<spawn_future_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto start{[](auto& state, auto& rcvr) noexcept -> void { state->consume(rcvr); }};
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using spawn_future_t = ::beman::execution::detail::spawn_future_t;
-export /* --------- */ inline constexpr spawn_future_t spawn_future{};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/spawn.hpp"
-namespace beman::execution::detail {
-struct spawn_t {
-    struct state_base {
-        virtual ~state_base()                    = default;
-        virtual auto complete() noexcept -> void = 0;
-    };
-
-    struct receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-        state_base* state{};
-
-        auto set_value() && noexcept -> void { this->state->complete(); }
-        auto set_stopped() && noexcept -> void { this->state->complete(); }
-    };
-
-    template <typename Alloc, ::beman::execution::scope_token Tok, ::beman::execution::sender Sndr>
-    struct state : state_base {
-        using op_t     = ::beman::execution::connect_result_t<Sndr, receiver>;
-        using alloc_t  = typename ::std::allocator_traits<Alloc>::template rebind_alloc<state>;
-        using traits_t = ::std::allocator_traits<alloc_t>;
-
-        state(Alloc a, Sndr&& sndr, Tok tok)
-            : alloc(a), op(::beman::execution::connect(::std::forward<Sndr>(sndr), receiver{this})), token(tok) {
-            if (this->token.try_associate()) {
-                ::beman::execution::start(this->op);
-            } else {
-                this->destroy();
-            }
-        }
-        auto complete() noexcept -> void override {
-            Tok tok(this->token);
-            this->destroy();
-            tok.disassociate();
-        }
-        auto destroy() noexcept -> void {
-            alloc_t all(this->alloc);
-            traits_t::destroy(all, this);
-            traits_t::deallocate(all, this, 1);
-        }
-#line 62 "include/beman/execution/detail/spawn.hpp"
-        alloc_t alloc;
-        op_t    op;
-        Tok     token;
-    };
-
-    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token, typename Env>
-    auto operator()(Sender&& sender, Token&& tok, Env&& env) const {
-        auto new_sender{tok.wrap(::std::forward<Sender>(sender))};
-        auto [all, senv] = ::beman::execution::detail::spawn_get_allocator(new_sender, env);
-
-        using sender_t = decltype(::beman::execution::write_env(::std::move(new_sender), senv));
-        using state_t  = state<decltype(all), Token, sender_t>;
-        using alloc_t  = typename ::std::allocator_traits<decltype(all)>::template rebind_alloc<state_t>;
-        using traits_t = ::std::allocator_traits<alloc_t>;
-        alloc_t  alloc(all);
-        state_t* op{traits_t::allocate(alloc, 1u)};
-        traits_t::construct(alloc, op, all, ::beman::execution::write_env(::std::move(new_sender), senv), tok);
-    }
-    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token>
-    auto operator()(Sender&& sender, Token&& token) const {
-        return (*this)(::std::forward<Sender>(sender), ::std::forward<Token>(token), ::beman::execution::env<>{});
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using spawn_t = ::beman::execution::detail::spawn_t;
-export /* --------- */ inline constexpr spawn_t spawn{};
-} // namespace beman::execution
-
-#line 32 "include/beman/execution/detail/on.hpp"
-namespace beman::execution::detail {
-struct on_t : ::beman::execution::sender_adaptor_closure<on_t> {
-    template <::beman::execution::detail::sender_for<on_t> OutSndr, typename Env>
-    auto transform_env(OutSndr&& out_sndr, Env&& env) const -> decltype(auto) {
-        auto&& data{out_sndr.template get<1>()};
-
-        if constexpr (::beman::execution::scheduler<decltype(data)>)
-            return ::beman::execution::detail::join_env(
-                ::beman::execution::detail::sched_env(::beman::execution::detail::forward_like<OutSndr>(data)
-
-                                                          ),
-                ::beman::execution::detail::fwd_env(::std::forward<Env>(env)));
-        else
-            return std::forward<Env>(env);
-    }
-#line 48 "include/beman/execution/detail/on.hpp"
-    template <typename>
-    struct env_needs_get_scheduler {
-        using sender_concept = ::beman::execution::sender_t;
-        template <typename Env>
-        auto get_completion_signatures(Env&&) const {
-            return env_needs_get_scheduler<Env>{};
-        }
-    };
-
-    template <::beman::execution::detail::sender_for<on_t> OutSndr, typename Env>
-    auto transform_sender(OutSndr&& out_sndr, Env&& env) const -> decltype(auto) {
-        struct not_a_scheduler {};
-        auto&& [_, data, child] = out_sndr;
-
-        if constexpr (::beman::execution::scheduler<decltype(data)>) {
-            auto sch{::beman::execution::detail::query_with_default(
-                ::beman::execution::get_scheduler, env, not_a_scheduler{})};
-            if constexpr (::std::same_as<not_a_scheduler, decltype(sch)>) {
-                return env_needs_get_scheduler<Env>{};
-            } else {
-                return ::beman::execution::continues_on(
-                    ::beman::execution::starts_on(::beman::execution::detail::forward_like<OutSndr>(data),
-                                                  ::beman::execution::detail::forward_like<OutSndr>(child)),
-                    ::std::move(sch));
-            }
-        } else {
-            auto& [sch, closure] = data;
-            auto orig_sch{::beman::execution::detail::query_with_default(
-                ::beman::execution::get_completion_scheduler<::beman::execution::set_value_t>,
-                ::beman::execution::get_env(child),
-                ::beman::execution::detail::query_with_default(
-                    ::beman::execution::get_scheduler, env, not_a_scheduler{}))};
-
-            if constexpr (::std::same_as<not_a_scheduler, decltype(orig_sch)>) {
-                return env_needs_get_scheduler<Env>{};
-            } else {
-                return ::beman::execution::detail::write_env(
-                    ::beman::execution::continues_on(
-                        ::beman::execution::detail::forward_like<OutSndr>(closure)(::beman::execution::continues_on(
-                            ::beman::execution::detail::write_env(
-                                ::beman::execution::detail::forward_like<OutSndr>(child),
-                                ::beman::execution::detail::sched_env(orig_sch)),
-                            sch)),
-                        orig_sch),
-                    ::beman::execution::detail::sched_env(env));
-            }
-        }
-    }
-#line 97 "include/beman/execution/detail/on.hpp"
-    template <::beman::execution::scheduler Sch, ::beman::execution::sender Sndr>
-        requires ::beman::execution::detail::is_sender_adaptor_closure<Sndr>
-    auto operator()(Sch&&, Sndr&&) const -> void =
-        BEMAN_EXECUTION_DELETE("on(sch, sndr) requires that sndr isn't both a sender and sender adaptor closure");
-
-    template <::beman::execution::scheduler                         Sch,
-              ::beman::execution::sender                            Sndr,
-              ::beman::execution::detail::is_sender_adaptor_closure Closure>
-        requires ::beman::execution::detail::is_sender_adaptor_closure<Sndr>
-    auto operator()(Sndr&&, Sch&&, Closure&&) const -> void =
-        BEMAN_EXECUTION_DELETE("on(sch, sndr) requires that sndr isn't both a sender and sender adaptor closure");
-
-    template <::beman::execution::scheduler Sch, ::beman::execution::sender Sndr>
-    auto operator()(Sch&& sch, Sndr&& sndr) const {
-        auto domain{::beman::execution::detail::query_with_default(
-            ::beman::execution::get_domain, sch, ::beman::execution::default_domain{})};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(*this, ::std::forward<Sch>(sch), ::std::forward<Sndr>(sndr)));
-    }
-    template <::beman::execution::scheduler                         Sch,
-              ::beman::execution::sender                            Sndr,
-              ::beman::execution::detail::is_sender_adaptor_closure Closure>
-    auto operator()(Sndr&& sndr, Sch&& sch, Closure&& closure) const {
-        auto domain{::beman::execution::detail::get_domain_early(sndr)};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this,
-                ::beman::execution::detail::product_type{::std::forward<Sch>(sch), ::std::forward<Closure>(closure)},
-                ::std::forward<Sndr>(sndr)));
-    }
-    template <::beman::execution::scheduler Sch, ::beman::execution::detail::is_sender_adaptor_closure Closure>
-    auto operator()(Sch&& sch, Closure&& closure) const {
-        return ::beman::execution::detail::sender_adaptor{
-            *this, ::std::forward<Sch>(sch), ::std::forward<Closure>(closure)};
-    }
-};
-
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using on_t = ::beman::execution::detail::on_t;
-export /* --------- */ inline constexpr ::beman::execution::on_t on{};
+    export using forwarding_query_t = ::beman::execution::forwarding_query_t;
+    export extern const beman::execution::forwarding_query_t forwarding_query;
 } // namespace beman::execution
+//export beman::execution::receiver;
+//export struct beman::execution::receiver_t;
diff --git a/tests/beman/execution/CMakeLists.txt b/tests/beman/execution/CMakeLists.txt
index 65238e5c..d8bb61bb 100644
--- a/tests/beman/execution/CMakeLists.txt
+++ b/tests/beman/execution/CMakeLists.txt
@@ -107,6 +107,7 @@ list(
     thread.test
     utilities.test
 )
+set(execution_tests exec-then.test)
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/include)
 

From 9779ac0c12df69f822845a595e7822683eb64792 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Mon, 2 Feb 2026 23:53:27 +0000
Subject: [PATCH 2/9] saving an apparently working alternate modules approach

---
 examples/CMakeLists.txt              |   1 -
 src/beman/execution/execution.cppm   | 236 ++++++++++++++++++++++++++-
 tests/beman/execution/CMakeLists.txt |   2 +-
 3 files changed, 233 insertions(+), 6 deletions(-)

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index c5bfc674..c68e6e17 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -33,7 +33,6 @@ set(EXAMPLES
     stopping
     when_all-cancel
 )
-set(EXAMPLES)
 
 if(BEMAN_USE_MODULES)
     list(APPEND EXAMPLES modules) # modules.cpp
diff --git a/src/beman/execution/execution.cppm b/src/beman/execution/execution.cppm
index a30cef80..0a8d1b17 100644
--- a/src/beman/execution/execution.cppm
+++ b/src/beman/execution/execution.cppm
@@ -6,13 +6,241 @@ module;
 // generated by ./bin/mk-module.py src/beman/execution/execution.cppm
 
 #include <beman/execution/execution.hpp>
+#include <beman/execution/stop_token.hpp>
 
 export module beman.execution;
 
 namespace beman::execution
 {
-    export using forwarding_query_t = ::beman::execution::forwarding_query_t;
-    export extern const beman::execution::forwarding_query_t forwarding_query;
+export using beman::execution::detail::pipeable::operator|;
+
+// [stoptoken.concepts], stop token concepts
+export using ::beman::execution::stoppable_token;
+export using ::beman::execution::unstoppable_token;
+
+// [stoptoken], class stop_token
+export using ::beman::execution::stop_token;
+
+// [stopsource], class stop_source
+export using ::beman::execution::stop_source;
+
+export using ::beman::execution::nostopstate_t;
+export using ::beman::execution::nostopstate;
+
+// [stopcallback], class template stop_callback
+export using ::beman::execution::stop_callback;
+
+// [stoptoken.never], class never_stop_token
+export using ::beman::execution::never_stop_token;
+
+// [stoptoken.inplace], class inplace_stop_token
+export using ::beman::execution::inplace_stop_token;
+
+// [stopsource.inplace], class inplace_stop_source
+export using ::beman::execution::inplace_stop_source;
+
+// [stopcallback.inplace], class template inplace_stop_callback
+export using ::beman::execution::inplace_stop_callback;
+export using ::beman::execution::stop_callback_for_t;
+
+#if 0
+    //-dk:TODO enable the execution policies
+    export using ::std::is_execution_policy;
+    export using ::std::is_execution_policy_v;
+
+    export using ::std::execution::sequenced_policy;
+    export using ::std::execution::parallel_policy;
+    export using ::std::execution::parallel_unsequenced_policy;
+    export using ::std::execution::unsequenced_policy;
+
+    export using ::std::execution::seq;
+    export using ::std::execution::par;
+    export using ::std::execution::par_unseq;
+    export using ::std::execution::unseq;
+#endif
+
+// [exec.queries], queries
+export using ::beman::execution::forwarding_query_t;
+export using ::beman::execution::get_allocator_t;
+export using ::beman::execution::get_stop_token_t;
+
+export using ::beman::execution::forwarding_query;
+export using ::beman::execution::get_allocator;
+export using ::beman::execution::get_stop_token;
+
+export using ::beman::execution::stop_token_of_t;
+
+export using ::beman::execution::get_domain_t;
+export using ::beman::execution::get_scheduler_t;
+export using ::beman::execution::get_delegation_scheduler_t;
+//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee_t;
+export using ::beman::execution::get_completion_scheduler_t;
+
+export using ::beman::execution::get_domain;
+export using ::beman::execution::get_scheduler;
+export using ::beman::execution::get_delegation_scheduler;
+//-dk:TODO export using ::beman::execution::forward_progress_guarantee;
+//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee;
+export using ::beman::execution::get_completion_scheduler;
+
+export using ::beman::execution::env;
+export using ::beman::execution::get_env_t;
+export using ::beman::execution::get_env;
+
+export using ::beman::execution::env_of_t;
+
+// [exec.domain.default], execution_domains
+export using ::beman::execution::default_domain;
+
+// [exec.sched], schedulers
+export using ::beman::execution::scheduler_t;
+export using ::beman::execution::scheduler;
+
+// [exec.recv], receivers
+export using ::beman::execution::receiver_t;
+export using ::beman::execution::receiver;
+export using ::beman::execution::receiver_of;
+
+export using ::beman::execution::set_value_t;
+export using ::beman::execution::set_error_t;
+export using ::beman::execution::set_stopped_t;
+
+export using ::beman::execution::set_value;
+export using ::beman::execution::set_error;
+export using ::beman::execution::set_stopped;
+
+// [exec.opstate], operation states
+export using ::beman::execution::operation_state_t;
+export using ::beman::execution::operation_state;
+export using ::beman::execution::start_t;
+export using ::beman::execution::start;
+
+// [exec.snd], senders
+export using ::beman::execution::sender_t;
+export using ::beman::execution::sender;
+export using ::beman::execution::sender_in;
+//-dk:TODO export using ::beman::execution::sender_to;
+
+// [exec.getcomplsigs], completion signatures
+export using ::beman::execution::get_completion_signatures_t;
+export using ::beman::execution::get_completion_signatures;
+export using ::beman::execution::completion_signatures_of_t;
+export using ::beman::execution::value_types_of_t;
+export using ::beman::execution::error_types_of_t;
+export using ::beman::execution::sends_stopped;
+export using ::beman::execution::tag_of_t;
+
+// [exec.snd.transform], sender transformations
+export using ::beman::execution::transform_sender;
+
+// [exec.snd.transform.env], environment transformations
+//-dk:TODO export using ::beman::execution::transform_env;
+
+// [exec.snd.apply], sender algorithm application
+export using ::beman::execution::apply_sender;
+
+// [exec.connect], the connect sender algorithm
+export using ::beman::execution::connect_t;
+export using ::beman::execution::connect;
+export using ::beman::execution::connect_result_t;
+
+// [exec.factories], sender factories
+export using ::beman::execution::just_t;
+export using ::beman::execution::just_error_t;
+export using ::beman::execution::just_stopped_t;
+export using ::beman::execution::schedule_t;
+
+export using ::beman::execution::just;
+export using ::beman::execution::just_error;
+export using ::beman::execution::just_stopped;
+export using ::beman::execution::schedule;
+export using ::beman::execution::read_env;
+
+export using ::beman::execution::schedule_result_t;
+
+// [exec.adapt], sender adaptors
+export using ::beman::execution::sender_adaptor_closure;
+
+export using ::beman::execution::starts_on_t;
+export using ::beman::execution::continues_on_t;
+export using ::beman::execution::on_t;
+export using ::beman::execution::schedule_from_t;
+export using ::beman::execution::then_t;
+export using ::beman::execution::upon_error_t;
+export using ::beman::execution::upon_stopped_t;
+export using ::beman::execution::let_value_t;
+export using ::beman::execution::let_error_t;
+export using ::beman::execution::let_stopped_t;
+export using ::beman::execution::bulk_t;
+export using ::beman::execution::split_t;
+export using ::beman::execution::when_all_t;
+export using ::beman::execution::when_all_with_variant_t;
+export using ::beman::execution::into_variant_t;
+//-dk:TODO export using ::beman::execution::stopped_as_optional_t;
+//-dk:TODO export using ::beman::execution::stopped_as_error_t;
+
+export using ::beman::execution::starts_on;
+export using ::beman::execution::continues_on;
+export using ::beman::execution::on;
+export using ::beman::execution::schedule_from;
+export using ::beman::execution::then;
+export using ::beman::execution::upon_error;
+export using ::beman::execution::upon_stopped;
+export using ::beman::execution::let_value;
+export using ::beman::execution::let_error;
+export using ::beman::execution::let_stopped;
+export using ::beman::execution::bulk;
+export using ::beman::execution::split;
+export using ::beman::execution::when_all;
+export using ::beman::execution::when_all_with_variant;
+export using ::beman::execution::into_variant;
+//-dk:TODO export using ::beman::execution::stopped_as_optional;
+//-dk:TODO export using ::beman::execution::stopped_as_error;
+
+// [exec.util.cmplsig]
+export using ::beman::execution::completion_signatures;
+
+// [exec.util.cmplsig.trans]
+//-dk:TODO export using ::beman::execution::transform_completion_signatures;
+//-dk:TODO export using ::beman::execution::transform_completion_signatures_of;
+
+// [exec.run.loop], run_loop
+export using ::beman::execution::run_loop;
+
+// [exec.consumers], consumers
+export using ::beman::execution::sync_wait_t;
+//-dk:TODO export using ::beman::execution::sync_wait_with_variant_t;
+
+export using ::beman::execution::sync_wait;
+//-dk:TODO export using ::beman::execution::sync_wait_with_variant;
+
+// [exec.as.awaitable]
+export using ::beman::execution::as_awaitable_t;
+export using ::beman::execution::as_awaitable;
+
+// [exec.with.awaitable.senders]
+export using ::beman::execution::with_awaitable_senders;
+
+//-dk:TODO add section
+export using ::beman::execution::prop;
+export using ::beman::execution::write_env_t;
+export using ::beman::execution::write_env;
+export using ::beman::execution::affine_on_t;
+export using ::beman::execution::affine_on;
+export using ::beman::execution::read_env_t;
+export using ::beman::execution::read_env;
+export using ::beman::execution::simple_counting_scope;
+export using ::beman::execution::counting_scope;
+export using ::beman::execution::scope_token;
+
+namespace detail {
+export using ::beman::execution::detail::env_promise;
+export using ::beman::execution::detail::await_result_type;
+export using ::beman::execution::detail::simple_allocator;
+export using ::beman::execution::detail::sync_wait_env;
+export using ::beman::execution::detail::sync_wait_result_type;
+export using ::beman::execution::detail::sync_wait_state;
+export using ::beman::execution::detail::sync_wait_receiver;
+} // namespace detail
+
 } // namespace beman::execution
-//export beman::execution::receiver;
-//export struct beman::execution::receiver_t;
diff --git a/tests/beman/execution/CMakeLists.txt b/tests/beman/execution/CMakeLists.txt
index d8bb61bb..9fdbbcdb 100644
--- a/tests/beman/execution/CMakeLists.txt
+++ b/tests/beman/execution/CMakeLists.txt
@@ -107,7 +107,7 @@ list(
     thread.test
     utilities.test
 )
-set(execution_tests exec-then.test)
+# set(execution_tests exec-then.test)
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/include)
 

From 9deda40987239c37fb271cd55a90c0d8f6eb9df3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Thu, 5 Feb 2026 01:08:59 +0000
Subject: [PATCH 3/9] fixed various issues to make `export import <name>`
 possible

---
 docs/modules.md                               |  191 +
 include/beman/execution/detail/associate.hpp  |   18 +-
 .../beman/execution/detail/basic_sender.hpp   |    6 +-
 include/beman/execution/detail/bulk.hpp       |   56 +-
 .../beman/execution/detail/connect_all.hpp    |    2 +-
 .../beman/execution/detail/continues_on.hpp   |   13 +-
 .../execution/detail/counting_scope_join.hpp  |   16 +-
 .../beman/execution/detail/into_variant.hpp   |   47 +-
 include/beman/execution/detail/just.hpp       |   12 +-
 include/beman/execution/detail/let.hpp        |    9 +-
 include/beman/execution/detail/read_env.hpp   |   15 +-
 .../beman/execution/detail/schedule_from.hpp  |   32 +-
 include/beman/execution/detail/then.hpp       |   43 +-
 include/beman/execution/detail/when_all.hpp   |   75 +-
 include/beman/execution/detail/write_env.hpp  |    7 +-
 src/beman/execution/CMakeLists.txt            |    2 +-
 src/beman/execution/execution-using.cppm      |  258 +
 src/beman/execution/execution.cppm            | 6668 ++++++++++++++++-
 tests/beman/execution/CMakeLists.txt          |    1 -
 tests/beman/execution/exec-affine-on.test.cpp |    1 +
 20 files changed, 7107 insertions(+), 365 deletions(-)
 create mode 100644 docs/modules.md
 create mode 100644 src/beman/execution/execution-using.cppm

diff --git a/docs/modules.md b/docs/modules.md
new file mode 100644
index 00000000..ea872815
--- /dev/null
+++ b/docs/modules.md
@@ -0,0 +1,191 @@
+# Supporting Modules
+
+Author: Dietmar Kühl dietmar.kuehl@me.com
+
+Originally [`beman.execution`](https://github.com/bemanproject/execution)
+was implemented with out `module` support. Eventually, `module`
+support in all compilers and in [`cmake`](https://cmake.org/) made
+it reaonable to add `module` support. This document describes some
+of the experiences of the journey adding `module` support for
+[`beman.execution`](https://github.com/bemanproject/execution). It is
+likely that my attempts on how to support `module`s were misguided and
+I'm happy to learn how things can be done properly or better.
+
+## History of Adding Module Support
+
+First, let's start describing what I did. The starting point for
+that was a working
+[`beman.execution`](https://github.com/bemanproject/execution)
+implementation which had no `module` support. It had tests and some
+examples and the `CMakeLists.txt` built these. The default build
+procedure run from the `Makefile` was already set up to use `ninja`.
+
+Claus Klein had started to land `cmake` support fo `module`s. In
+particular there were `cmake` rules to detect whether there is a
+dependency scanner and whether `import std;` is supported. The
+statement from Claus was that using `import std;` would be the
+second step - the first step is to actually create a `module` for
+[`beman.execution`](https://github.com/bemanproject/execution)
+including the standard library headers.
+
+### Use `export using`
+
+I had tried to create a `module` right after the Hagenberg meeting
+at the end of 2025. Since I was clueless how to go about that I had
+asked peolple who worked on the `module` specification and implemented
+the corresponding support in compilers. The recommendation was to
+create a `module` file, include all the headers, start the `module`,
+and have `export using <name>;` declarations. That is, something
+like this:
+
+```c++
+module;
+
+#include <beman/execution/execution.hpp>
+
+export module beman.execution;
+
+namespace beman::execution {
+    export using ::beman::execution::forwarding_query_t;
+    // more of these - one for each name to be exported
+}
+```
+
+Creating a file like that was fairly mechanical work and I just did
+it.  I tried it. There were a bunch of errors which I could work
+out easily but eventually I got stuck with unscruitible errors.
+Since I never planned to write about the experience I don't recall
+what the errors were.  When I asked about it the message was that
+neither `cmake` nor the compilers are quite there. So I abondoned
+this first attempt.
+
+Time passed and in the beginning of 2026 some `cmake` support for
+`module`s was added via a PR to the repository. The code wasn't
+ready to use `module` but it seems reasonable to retry. A first
+feeble try to get things built using the `export using` approach
+again resulted in errors and there were voice stating that this
+won't work but `module` support should actually work. The error
+messages seemed to imply that I should `export` the declarations
+immediately. So I abandoned that particular approach, again.
+
+### Generate Module Friendly Code: `mk-module.py`
+
+The attempts up to this point had indicated a few things which
+were somewhat misaligned with the way the code in 
+[`beman.execution`](https://github.com/bemanproject/execution)
+is laid out. The code is structured into lots of small _components_
+(loosely based on John Lakos's idea of components in his 1996 version
+of "Large-Scale C++"). Each component consists of
+
+<ul>
+  <li>
+  a header declaring an entity like a class/class template, a
+  function/function template, or a concept as well as everything
+  needed to do so;
+  </li>
+  <li>
+  a test file verifying that everything promised is, indeed, defined
+  and confirm using tests that it works;
+  </li>
+  <li>
+  an optional source file with the definitions of what is declared
+  in the header; in case of templates the header will actually
+  contain these definitions
+  </li>
+</ul>
+
+Each component's file includes all necessary headers and a component
+`A` is said to _directly depend on a component_ `D` if any of `A`'s
+files includes `D`'s header. Creating a graph with the components
+as nodes and directed edges from each component to all components
+it directly depends on results in dependency graph which does not
+contain any cycles. Building the code without `module`s just works
+fine.
+
+When trying directly `export` the declarations of names when they
+are first declared, it quickly transpired that this doesn't work
+due to the structure of `module` files required by contemporary
+compilers:
+
+<ol>
+  <li>
+  The first 7 charactesr of a `module` file shall be `module;`
+  without anything preceding them.  [`g++`](https://gcc.gnu.org/)
+  and [`clang++`](https://llvm.org/) are somewhat relaxed about
+  this requirement but some compiler is rather strict. This, however,
+  is at least easily achieved.
+  </li>
+  <li>
+  Any `export` of a name has to follow the `module`'s name declaration,
+  in this case after `export module beman.execution;`. This makes
+  sense: the compiler needs to know what `module` the names belong to.
+  </li>
+  <li>
+  The problem comes with any standard library header included after
+  this name declaration: that entirely confuses the compilers. That
+  is, all headers really need to be included before the name
+  declaration. That is pretty much _not_ how the components in
+  [`beman.execution`](https://github.com/bemanproject/execution) are
+  orgnaized.
+  </li>
+</ol>
+
+To still achieve the objective of `export`ing a name when it first
+gets declared, the structure needs to be change. However, the componets
+are organized in a consistent structure. So the idea is to use this structure
+to reorganize the files for `module` builds:
+
+<ol>
+  <li>
+  Add an `export` keyword in front of any declaration which should be
+  `export`ed (well, really a name which can be defined so the headers can
+  function both when building a `module` and when just using headers; the
+  implementation uses `BEMAN_EXECUTION_EXPORT`).
+  </li>
+  <li>
+  Use a script (named
+  [`bin/mk-module.py`](https://github.com/bemanproject/execution/blob/main/bin/mk-module.py))
+  to create a `module` definition:
+    <ol>
+      <li>
+      Start the file with `module;` (and some header stating the
+      file is generated).
+      </li>
+      <li>
+      Create a list of all used standard library headers and put
+      these right below the files head.
+      </li>
+      <li>
+      Add the `module` name declaration.
+      </li>
+      <li>
+      Copy the declaration from all the components in correct
+      dependency order, i.e., each component's declarations is
+      preceded by the declarations it directly depends on.
+      </li>
+    </ol>
+  </li>
+  <li>Profit!</li>
+</ol>
+
+Creating the script to write the file was reasonably straight forward
+although I spend way too much time making it fancy and include
+suitable `#line` directives to find the actual source. Compiling
+the resulting still didn't quite work, of course. There was a bunch
+of silly errors in the component headers which could be quickly
+resolved, though. That wasn't quite as true for the test files,
+though (more [ruminations on tests](#modules-vs-testing) below):
+
+-dk:TODO `export using`
+-dk:TODO `import std;`
+
+## Changes Needed to Support Modules
+
+-dk:TODO order of headers vs. import
+-dk:TODO fixes for join_env
+-dk:TODO requires declaration of variant, optional, etc.
+
+## Scanning
+
+## Modules vs. Testing
+
diff --git a/include/beman/execution/detail/associate.hpp b/include/beman/execution/detail/associate.hpp
index 33d89713..85001d2f 100644
--- a/include/beman/execution/detail/associate.hpp
+++ b/include/beman/execution/detail/associate.hpp
@@ -93,10 +93,11 @@ struct impls_for<associate_t> : ::beman::execution::detail::default_impls {
                                                       typename ::std::remove_cvref_t<Data>::wrap_sender,
                                                       Receiver>> {};
 
-    static constexpr auto get_state =
-        []<typename Sender, typename Receiver>(Sender&& sender, Receiver& receiver) noexcept(
-            ::std::is_nothrow_constructible_v<::std::remove_cvref_t<Sender>, Sender>&&
-                get_noexcept<::std::remove_cvref_t<Sender>, Receiver>::value) {
+    struct get_state_impl {
+        template <typename Sender, typename Receiver>
+        auto operator()(Sender&& sender, Receiver& receiver) const
+            noexcept(::std::is_nothrow_constructible_v<::std::remove_cvref_t<Sender>, Sender> &&
+                     get_noexcept<::std::remove_cvref_t<Sender>, Receiver>::value) {
             auto [_, data] = ::std::forward<Sender>(sender);
             auto dataParts{data.release()};
 
@@ -143,8 +144,13 @@ struct impls_for<associate_t> : ::beman::execution::detail::default_impls {
             };
             return dataParts ? op_state(::std::move(dataParts->first), ::std::move(dataParts->second), receiver)
                              : op_state(receiver);
-        };
-    static constexpr auto start = [](auto& state, auto&&) noexcept -> void { state.run(); };
+        }
+    };
+    static constexpr auto get_state{get_state_impl{}};
+    struct start_impl {
+        auto operator()(auto& state, auto&&) const noexcept -> void { state.run(); }
+    };
+    static constexpr auto start{start_impl{}};
 };
 
 template <typename Data, typename Env>
diff --git a/include/beman/execution/detail/basic_sender.hpp b/include/beman/execution/detail/basic_sender.hpp
index a7e1bc92..62bba28a 100644
--- a/include/beman/execution/detail/basic_sender.hpp
+++ b/include/beman/execution/detail/basic_sender.hpp
@@ -28,8 +28,8 @@ namespace beman::execution::detail {
  */
 template <typename Tag, typename Data, typename... Child>
 struct basic_sender : ::beman::execution::detail::product_type<Tag, Data, Child...> {
-    friend struct ::beman::execution::detail::connect_t;
-    friend struct ::beman::execution::get_completion_signatures_t;
+    //-dk:TODO friend struct ::beman::execution::detail::connect_t;
+    //-dk:TODO friend struct ::beman::execution::get_completion_signatures_t;
     using sender_concept = ::beman::execution::sender_t;
     using indices_for    = ::std::index_sequence_for<Child...>;
 
@@ -43,7 +43,7 @@ struct basic_sender : ::beman::execution::detail::product_type<Tag, Data, Child.
         requires(!::beman::execution::receiver<Receiver>)
     auto connect(Receiver receiver) = BEMAN_EXECUTION_DELETE("the passed receiver doesn't model receiver");
 
-  private:
+    //-dk:TODO private:
 #if __cpp_explicit_this_parameter < 302110L //-dk:TODO need to figure out how to use explicit this with forwarding
     template <::beman::execution::receiver Receiver>
     auto connect(Receiver receiver) & noexcept(
diff --git a/include/beman/execution/detail/bulk.hpp b/include/beman/execution/detail/bulk.hpp
index d4613a1a..b2ace14a 100644
--- a/include/beman/execution/detail/bulk.hpp
+++ b/include/beman/execution/detail/bulk.hpp
@@ -57,38 +57,40 @@ struct bulk_t : ::beman::execution::sender_adaptor_closure<bulk_t> {
 template <>
 struct impls_for<bulk_t> : ::beman::execution::detail::default_impls {
 
-    static constexpr auto complete = []<class Index, class Shape, class Fun, class Rcvr, class Tag, class... Args>(
-                                         Index,
-                                         ::beman::execution::detail::product_type<Shape, Fun>& state,
-                                         Rcvr&                                                 rcvr,
-                                         Tag,
-                                         Args&&... args) noexcept -> void
-        requires(!::std::same_as<Tag, set_value_t> || std::is_invocable_v<Fun, Shape, Args...>)
-    {
-        if constexpr (std::same_as<Tag, set_value_t>) {
-            auto& [shape, f] = state;
-
-            using s_type = std::remove_cvref_t<decltype(shape)>;
-
-            constexpr bool nothrow = noexcept(f(s_type(shape), args...));
-
-            try {
-                [&]() noexcept(nothrow) {
-                    for (decltype(s_type(shape)) i = 0; i < shape; i++) {
-                        f(s_type(i), args...);
+    struct complete_impl {
+        template <class Index, class Shape, class Fun, class Rcvr, class Tag, class... Args>
+            requires(!::std::same_as<Tag, set_value_t> || std::is_invocable_v<Fun, Shape, Args...>)
+        auto operator()(Index,
+                        ::beman::execution::detail::product_type<Shape, Fun>& state,
+                        Rcvr&                                                 rcvr,
+                        Tag,
+                        Args&&... args) const noexcept -> void {
+            if constexpr (std::same_as<Tag, set_value_t>) {
+                auto& [shape, f] = state;
+
+                using s_type = std::remove_cvref_t<decltype(shape)>;
+
+                constexpr bool nothrow = noexcept(f(s_type(shape), args...));
+
+                try {
+                    [&]() noexcept(nothrow) {
+                        for (decltype(s_type(shape)) i = 0; i < shape; i++) {
+                            f(s_type(i), args...);
+                        }
+                        Tag()(std::move(rcvr), std::forward<Args>(args)...);
+                    }();
+
+                } catch (...) {
+                    if constexpr (not nothrow) {
+                        ::beman::execution::set_error(std::move(rcvr), std::current_exception());
                     }
-                    Tag()(std::move(rcvr), std::forward<Args>(args)...);
-                }();
-
-            } catch (...) {
-                if constexpr (not nothrow) {
-                    ::beman::execution::set_error(std::move(rcvr), std::current_exception());
                 }
+            } else {
+                Tag()(std::move(rcvr), std::forward<Args>(args)...);
             }
-        } else {
-            Tag()(std::move(rcvr), std::forward<Args>(args)...);
         }
     };
+    static constexpr auto complete{complete_impl{}};
 };
 
 template <typename, typename, typename>
diff --git a/include/beman/execution/detail/connect_all.hpp b/include/beman/execution/detail/connect_all.hpp
index 80d5b4c8..cbba0645 100644
--- a/include/beman/execution/detail/connect_all.hpp
+++ b/include/beman/execution/detail/connect_all.hpp
@@ -123,7 +123,7 @@ struct connect_all_t {
  * \internal
  */
 //-dk:TODO the export below shouldn't be needed, but MSVC++ seems to require it (2026-02-01)
-BEMAN_EXECUTION_EXPORT constexpr connect_all_t connect_all{}; //-dk:TODO detail export
+BEMAN_EXECUTION_EXPORT inline constexpr connect_all_t connect_all{}; //-dk:TODO detail export
 } // namespace beman::execution::detail
 
 #include <beman/execution/detail/suppress_pop.hpp>
diff --git a/include/beman/execution/detail/continues_on.hpp b/include/beman/execution/detail/continues_on.hpp
index 1a53e8cc..02a5f52d 100644
--- a/include/beman/execution/detail/continues_on.hpp
+++ b/include/beman/execution/detail/continues_on.hpp
@@ -64,11 +64,14 @@ struct continues_on_t {
  */
 template <>
 struct impls_for<::beman::execution::detail::continues_on_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_attrs{[](const auto& data, const auto& child) noexcept -> decltype(auto) {
-        return ::beman::execution::detail::join_env(
-            ::beman::execution::detail::sched_attrs(data),
-            ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
-    }};
+    struct get_attrs_impl {
+        auto operator()(const auto& data, const auto& child) const noexcept -> decltype(auto) {
+            return ::beman::execution::detail::join_env(
+                ::beman::execution::detail::sched_attrs(data),
+                ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
+        }
+    };
+    static constexpr auto get_attrs{get_attrs_impl{}};
 };
 
 /*!
diff --git a/include/beman/execution/detail/counting_scope_join.hpp b/include/beman/execution/detail/counting_scope_join.hpp
index 2d557692..1bf15008 100644
--- a/include/beman/execution/detail/counting_scope_join.hpp
+++ b/include/beman/execution/detail/counting_scope_join.hpp
@@ -75,11 +75,19 @@ struct beman::execution::detail::counting_scope_join_t::state : ::beman::executi
 namespace beman::execution::detail {
 template <>
 struct impls_for<::beman::execution::detail::counting_scope_join_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_state = []<typename Receiver>(auto&& sender, Receiver& receiver) noexcept(false) {
-        auto [_, self] = sender;
-        return ::beman::execution::detail::counting_scope_join_t::state<Receiver>(self, receiver);
+    struct get_state_impl {
+
+        template <typename Receiver>
+        auto operator()(auto&& sender, Receiver& receiver) const noexcept(false) {
+            auto [_, self] = sender;
+            return ::beman::execution::detail::counting_scope_join_t::state<Receiver>(self, receiver);
+        }
+    };
+    static constexpr auto get_state{get_state_impl{}};
+    struct start_impl {
+        auto operator()(auto& s, auto&) const noexcept { s.start(); }
     };
-    static constexpr auto start = [](auto& s, auto&) noexcept { s.start(); };
+    static constexpr auto start{start_impl{}};
 };
 } // namespace beman::execution::detail
 
diff --git a/include/beman/execution/detail/into_variant.hpp b/include/beman/execution/detail/into_variant.hpp
index 7905a582..b4ff8169 100644
--- a/include/beman/execution/detail/into_variant.hpp
+++ b/include/beman/execution/detail/into_variant.hpp
@@ -45,30 +45,37 @@ BEMAN_EXECUTION_EXPORT struct into_variant_t {
 
 template <>
 struct impls_for<::beman::execution::detail::into_variant_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_state = []<typename Sender, typename Receiver>(Sender&&, Receiver&&) noexcept
-        -> ::std::type_identity<::beman::execution::value_types_of_t<::beman::execution::detail::child_type<Sender>,
-                                                                     ::beman::execution::env_of_t<Receiver>>> {
-        return {};
+    struct get_state_impl {
+        template <typename Sender, typename Receiver>
+        auto operator()(Sender&&, Receiver&&) const noexcept -> ::std::type_identity<
+            ::beman::execution::value_types_of_t<::beman::execution::detail::child_type<Sender>,
+                                                 ::beman::execution::env_of_t<Receiver>>> {
+            return {};
+        }
     };
-    static constexpr auto complete = []<typename State, typename Tag, typename... Args>(
-                                         auto, State, auto& receiver, Tag, Args&&... args) noexcept -> void {
-        if constexpr (::std::same_as<Tag, ::beman::execution::set_value_t>) {
-            using variant_type = typename State::type;
-            using tuple_type   = ::beman::execution::detail::decayed_tuple<Args...>;
-            try {
-                if constexpr (sizeof...(Args) == 0u)
-                    ::beman::execution::set_value(::std::move(receiver));
-                else
-                    ::beman::execution::set_value(::std::move(receiver),
-                                                  variant_type(tuple_type{::std::forward<Args>(args)...}));
-            } catch (...) {
-                ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-            }
+    static constexpr auto get_state{get_state_impl{}};
+    struct complete_impl {
+        template <typename State, typename Tag, typename... Args>
+        auto operator()(auto, State, auto& receiver, Tag, Args&&... args) const noexcept -> void {
+            if constexpr (::std::same_as<Tag, ::beman::execution::set_value_t>) {
+                using variant_type = typename State::type;
+                using tuple_type   = ::beman::execution::detail::decayed_tuple<Args...>;
+                try {
+                    if constexpr (sizeof...(Args) == 0u)
+                        ::beman::execution::set_value(::std::move(receiver));
+                    else
+                        ::beman::execution::set_value(::std::move(receiver),
+                                                      variant_type(tuple_type{::std::forward<Args>(args)...}));
+                } catch (...) {
+                    ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+                }
 
-        } else {
-            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
+            } else {
+                Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
+            }
         }
     };
+    static constexpr auto complete{complete_impl{}};
 };
 
 template <typename Sender, typename State, typename Env>
diff --git a/include/beman/execution/detail/just.hpp b/include/beman/execution/detail/just.hpp
index 495697a9..1d858cb8 100644
--- a/include/beman/execution/detail/just.hpp
+++ b/include/beman/execution/detail/just.hpp
@@ -50,11 +50,15 @@ struct completion_signatures_for_impl<
 
 template <typename Completion>
 struct impls_for<just_t<Completion>> : ::beman::execution::detail::default_impls {
-    static constexpr auto start = []<typename State>(State& state, auto& receiver) noexcept -> void {
-        [&state, &receiver]<::std::size_t... I>(::std::index_sequence<I...>) {
-            Completion()(::std::move(receiver), ::std::move(state.template get<I>())...);
-        }(::std::make_index_sequence<State::size()>{});
+    struct start_impl {
+        template <typename State>
+        auto operator()(State& state, auto& receiver) const noexcept -> void {
+            [&state, &receiver]<::std::size_t... I>(::std::index_sequence<I...>) {
+                Completion()(::std::move(receiver), ::std::move(state.template get<I>())...);
+            }(::std::make_index_sequence<State::size()>{});
+        }
     };
+    static constexpr auto start{start_impl{}};
 };
 } // namespace beman::execution::detail
 
diff --git a/include/beman/execution/detail/let.hpp b/include/beman/execution/detail/let.hpp
index 60448fb7..ace849b1 100644
--- a/include/beman/execution/detail/let.hpp
+++ b/include/beman/execution/detail/let.hpp
@@ -179,8 +179,9 @@ struct impls_for<::beman::execution::detail::let_t<Completion>> : ::beman::execu
         ::beman::execution::start(
             state.ops2.template emplace<decltype(mkop())>(beman::execution::detail::emplace_from{mkop}));
     }
-    static constexpr auto complete{
-        []<class Tag, class... Args>(auto, auto& state, auto& receiver, Tag, Args&&... args) {
+    struct complete_impl {
+        template <class Tag, class... Args>
+        auto operator()(auto, auto& state, auto& receiver, Tag, Args&&... args) const {
             if constexpr (::std::same_as<Tag, Completion>) {
                 try {
                     let_bind(state, receiver, ::std::forward<Args>(args)...);
@@ -191,7 +192,9 @@ struct impls_for<::beman::execution::detail::let_t<Completion>> : ::beman::execu
             } else {
                 Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
             }
-        }};
+        }
+    };
+    static constexpr auto complete{complete_impl{}};
 };
 
 template <typename Completion, typename Fun, typename Sender, typename Env>
diff --git a/include/beman/execution/detail/read_env.hpp b/include/beman/execution/detail/read_env.hpp
index 020319f6..aec3b0df 100644
--- a/include/beman/execution/detail/read_env.hpp
+++ b/include/beman/execution/detail/read_env.hpp
@@ -30,14 +30,17 @@ struct read_env_t {
 
 template <>
 struct impls_for<::beman::execution::detail::read_env_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto start = [](auto query, auto& receiver) noexcept -> void {
-        try {
-            auto env{::beman::execution::get_env(receiver)};
-            ::beman::execution::set_value(::std::move(receiver), query(env));
-        } catch (...) {
-            ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+    struct start_impl {
+        auto operator()(auto query, auto& receiver) const noexcept -> void {
+            try {
+                auto env{::beman::execution::get_env(receiver)};
+                ::beman::execution::set_value(::std::move(receiver), query(env));
+            } catch (...) {
+                ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+            }
         }
     };
+    static constexpr auto start{start_impl{}};
 };
 
 template <typename Query, typename Env>
diff --git a/include/beman/execution/detail/schedule_from.hpp b/include/beman/execution/detail/schedule_from.hpp
index 195b1aab..f2b7cdcb 100644
--- a/include/beman/execution/detail/schedule_from.hpp
+++ b/include/beman/execution/detail/schedule_from.hpp
@@ -114,15 +114,20 @@ struct impls_for<::beman::execution::detail::schedule_from_t> : ::beman::executi
               op_state(::beman::execution::connect(::beman::execution::schedule(sch), receiver_t{this})) {}
     };
 
-    static constexpr auto get_attrs{[](const auto& data, const auto& child) noexcept -> decltype(auto) {
-        return ::beman::execution::detail::join_env(
-            ::beman::execution::detail::sched_attrs(data),
-            ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
-    }};
-    static constexpr auto get_state{
-        []<typename Sender, typename Receiver>(Sender&& sender, Receiver& receiver) //-dk:TODO noexcept(see below)
+    struct get_attrs_impl {
+
+        auto operator()(const auto& data, const auto& child) const noexcept -> decltype(auto) {
+            return ::beman::execution::detail::join_env(
+                ::beman::execution::detail::sched_attrs(data),
+                ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
+        }
+    };
+    static constexpr auto get_attrs{get_attrs_impl{}};
+    struct get_state_impl {
+        template <typename Sender, typename Receiver>
             requires ::beman::execution::sender_in<::beman::execution::detail::child_type<Sender>,
                                                    ::beman::execution::env_of_t<Receiver>>
+        auto operator()(Sender&& sender, Receiver& receiver) const //-dk:TODO noexcept(see below)
         {
             auto sch{sender.template get<1>()};
 
@@ -142,9 +147,12 @@ struct impls_for<::beman::execution::detail::schedule_from_t> : ::beman::executi
                                                                  ::beman::execution::set_stopped_t()>>>>>>;
 
             return state_type<Receiver, sched_t, variant_t>(sch, receiver);
-        }};
-    static constexpr auto complete{
-        []<typename Tag, typename... Args>(auto, auto& state, auto& receiver, Tag, Args&&... args) noexcept -> void {
+        };
+    };
+    static constexpr auto get_state{get_state_impl{}};
+    struct complete_impl {
+        template <typename Tag, typename... Args>
+        auto operator()(auto, auto& state, auto& receiver, Tag, Args&&... args) const noexcept -> void {
             using result_t         = ::beman::execution::detail::decayed_tuple<Tag, Args...>;
             constexpr bool nothrow = ::std::is_nothrow_constructible_v<result_t, Tag, Args...>;
 
@@ -161,7 +169,9 @@ struct impls_for<::beman::execution::detail::schedule_from_t> : ::beman::executi
                 return;
 
             ::beman::execution::start(state.op_state);
-        }};
+        }
+    };
+    static constexpr auto complete{complete_impl{}};
 };
 
 template <typename Scheduler, typename Sender, typename Env>
diff --git a/include/beman/execution/detail/then.hpp b/include/beman/execution/detail/then.hpp
index c393b0fc..af24f68a 100644
--- a/include/beman/execution/detail/then.hpp
+++ b/include/beman/execution/detail/then.hpp
@@ -58,31 +58,34 @@ struct then_t : ::beman::execution::sender_adaptor_closure<then_t<Completion>> {
 template <typename Completion>
 struct impls_for<then_t<Completion>> : ::beman::execution::detail::default_impls {
     // NOLINTBEGIN(bugprone-exception-escape)
-    static constexpr auto complete =
-        []<typename Tag, typename... Args>(auto, auto& fun, auto& receiver, Tag, Args&&... args) noexcept -> void {
-        if constexpr (::std::same_as<Completion, Tag>) {
-            try {
-                auto invoke = [&] { return ::std::invoke(::std::move(fun), ::std::forward<Args>(args)...); };
-                if constexpr (::std::same_as<void, decltype(invoke())>) {
-                    invoke();
-                    ::beman::execution::set_value(::std::move(receiver));
-                } else {
-                    ::beman::execution::set_value(::std::move(receiver), invoke());
-                }
-            } catch (...) {
-                if constexpr (not noexcept(::std::invoke(::std::move(fun), ::std::forward<Args>(args)...)
+    struct complete_impl {
+        template <typename Tag, typename... Args>
+        auto operator()(auto, auto& fun, auto& receiver, Tag, Args&&... args) const noexcept -> void {
+            if constexpr (::std::same_as<Completion, Tag>) {
+                try {
+                    auto invoke = [&] { return ::std::invoke(::std::move(fun), ::std::forward<Args>(args)...); };
+                    if constexpr (::std::same_as<void, decltype(invoke())>) {
+                        invoke();
+                        ::beman::execution::set_value(::std::move(receiver));
+                    } else {
+                        ::beman::execution::set_value(::std::move(receiver), invoke());
+                    }
+                } catch (...) {
+                    if constexpr (not noexcept(::std::invoke(::std::move(fun), ::std::forward<Args>(args)...)
 
-                                               )) {
-                    static_assert(
-                        noexcept(::beman::execution::set_error(::std::move(receiver), ::std::current_exception())));
-                    ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+                                                   )) {
+                        static_assert(noexcept(
+                            ::beman::execution::set_error(::std::move(receiver), ::std::current_exception())));
+                        ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+                    }
                 }
+            } else {
+                static_assert(noexcept(Tag()(::std::move(receiver), ::std::forward<Args>(args)...)));
+                Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
             }
-        } else {
-            static_assert(noexcept(Tag()(::std::move(receiver), ::std::forward<Args>(args)...)));
-            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
         }
     };
+    static constexpr auto complete{complete_impl{}};
     // NOLINTEND(bugprone-exception-escape)
 };
 
diff --git a/include/beman/execution/detail/when_all.hpp b/include/beman/execution/detail/when_all.hpp
index 031bd7d0..47f1474b 100644
--- a/include/beman/execution/detail/when_all.hpp
+++ b/include/beman/execution/detail/when_all.hpp
@@ -78,20 +78,26 @@ struct when_all_value_types<::beman::execution::detail::type_list<T...>> {
 
 template <>
 struct impls_for<::beman::execution::detail::when_all_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_attrs{[](auto&&, auto&&... sender) {
-        using common_t =
-            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
-        if constexpr (::std::same_as<common_t, ::beman::execution::default_domain>)
-            return ::beman::execution::env<>{};
-        else
-            return ::beman::execution::detail::make_env(::beman::execution::get_domain, common_t{});
-    }};
-    static constexpr auto get_env{
-        []<typename State, typename Receiver>(auto&&, State& state, const Receiver& receiver) noexcept {
+    struct get_attrs_impl {
+        auto operator()(auto&&, auto&&... sender) const {
+            using common_t =
+                typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
+            if constexpr (::std::same_as<common_t, ::beman::execution::default_domain>)
+                return ::beman::execution::env<>{};
+            else
+                return ::beman::execution::detail::make_env(::beman::execution::get_domain, common_t{});
+        }
+    };
+    static constexpr auto get_attrs{get_attrs_impl{}};
+    struct get_env_impl {
+        template <typename State, typename Receiver>
+        auto operator()(auto&&, State& state, const Receiver& receiver) const noexcept {
             return ::beman::execution::detail::join_env(
                 ::beman::execution::detail::make_env(::beman::execution::get_stop_token, state.stop_src.get_token()),
                 ::beman::execution::get_env(receiver));
-        }};
+        }
+    };
+    static constexpr auto get_env{get_env_impl{}};
 
     enum class disposition : unsigned char { started, error, stopped };
 
@@ -183,25 +189,32 @@ struct impls_for<::beman::execution::detail::when_all_t> : ::beman::execution::d
             return state_type<Receiver, Sender...>{};
         }
     };
-    static constexpr auto get_state{[]<typename Sender, typename Receiver>(Sender&& sender, Receiver&) noexcept(
-                                        noexcept(std::forward<Sender>(sender).apply(make_state<Receiver>{}))) {
-        return std::forward<Sender>(sender).apply(make_state<Receiver>{});
-    }};
-    static constexpr auto start{[]<typename State, typename Receiver, typename... Ops>(
-                                    State& state, Receiver& receiver, Ops&... ops) noexcept -> void {
-        state.receiver = &receiver;
-        state.on_stop.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(receiver)),
-                              ::beman::execution::detail::on_stop_request{state});
-        if (state.stop_src.stop_requested()) {
-            state.on_stop.reset();
-            ::beman::execution::set_stopped(std::move(receiver));
-        } else {
-            (::beman::execution::start(ops), ...);
+    struct get_state_impl {
+        template <typename Sender, typename Receiver>
+        auto operator()(Sender&& sender, Receiver&) const
+            noexcept(noexcept(std::forward<Sender>(sender).apply(make_state<Receiver>{}))) {
+            return std::forward<Sender>(sender).apply(make_state<Receiver>{});
         }
-    }};
-    static constexpr auto complete{
-        []<typename Index, typename State, typename Receiver, typename Set, typename... Args>(
-            Index, State& state, Receiver& receiver, Set, Args&&... args) noexcept -> void {
+    };
+    static constexpr auto get_state{get_state_impl{}};
+    struct start_impl {
+        template <typename State, typename Receiver, typename... Ops>
+        auto operator()(State& state, Receiver& receiver, Ops&... ops) const noexcept -> void {
+            state.receiver = &receiver;
+            state.on_stop.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(receiver)),
+                                  ::beman::execution::detail::on_stop_request{state});
+            if (state.stop_src.stop_requested()) {
+                state.on_stop.reset();
+                ::beman::execution::set_stopped(std::move(receiver));
+            } else {
+                (::beman::execution::start(ops), ...);
+            }
+        }
+    };
+    static constexpr auto start{start_impl{}};
+    struct complete_impl {
+        template <typename Index, typename State, typename Receiver, typename Set, typename... Args>
+        auto operator()(Index, State& state, Receiver& receiver, Set, Args&&... args) const noexcept -> void {
             if constexpr (::std::same_as<Set, ::beman::execution::set_error_t>) {
                 if (disposition::error != state.disp.exchange(disposition::error)) {
                     state.stop_src.request_stop();
@@ -231,7 +244,9 @@ struct impls_for<::beman::execution::detail::when_all_t> : ::beman::execution::d
                 }
             }
             state.arrive(receiver);
-        }};
+        }
+    };
+    static constexpr auto complete{complete_impl{}};
 };
 
 template <typename Data, typename Env, typename... Sender>
diff --git a/include/beman/execution/detail/write_env.hpp b/include/beman/execution/detail/write_env.hpp
index 1cfc3e60..3b5c2d67 100644
--- a/include/beman/execution/detail/write_env.hpp
+++ b/include/beman/execution/detail/write_env.hpp
@@ -44,9 +44,12 @@ struct completion_signatures_for_impl<
 
 template <>
 struct impls_for<write_env_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_env = [](auto, const auto& state, const auto& receiver) noexcept {
-        return ::beman::execution::detail::join_env(state, ::beman::execution::get_env(receiver));
+    struct get_env_impl {
+        auto operator()(auto, const auto& state, const auto& receiver) const noexcept {
+            return ::beman::execution::detail::join_env(state, ::beman::execution::get_env(receiver));
+        }
     };
+    static constexpr auto get_env = get_env_impl{};
 };
 
 inline constexpr write_env_t write_env{};
diff --git a/src/beman/execution/CMakeLists.txt b/src/beman/execution/CMakeLists.txt
index 10774bac..ebd7bdf6 100644
--- a/src/beman/execution/CMakeLists.txt
+++ b/src/beman/execution/CMakeLists.txt
@@ -201,7 +201,7 @@ if(BEMAN_USE_MODULES)
         PUBLIC
             FILE_SET CXX_MODULES
                 BASE_DIRS ${PROJECT_SOURCE_DIR}/src/beman/execution
-                FILES ${PROJECT_SOURCE_DIR}/src/beman/execution/execution.cppm
+                FILES ${PROJECT_SOURCE_DIR}/src/beman/execution/execution-using.cppm
     )
     target_link_libraries(${TARGET_PREFIX} PUBLIC ${TARGET_NAME})
 endif()
diff --git a/src/beman/execution/execution-using.cppm b/src/beman/execution/execution-using.cppm
new file mode 100644
index 00000000..5ff6ed6a
--- /dev/null
+++ b/src/beman/execution/execution-using.cppm
@@ -0,0 +1,258 @@
+module;
+// src/beman/execution/execution-using.cppm
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <beman/execution/execution.hpp>
+#include <beman/execution/stop_token.hpp>
+
+export module beman.execution;
+
+namespace beman::execution {
+export using beman::execution::detail::pipeable::operator|;
+
+// [stoptoken.concepts], stop token concepts
+export using ::beman::execution::stoppable_token;
+export using ::beman::execution::unstoppable_token;
+
+// [stoptoken], class stop_token
+export using ::beman::execution::stop_token;
+
+// [stopsource], class stop_source
+export using ::beman::execution::stop_source;
+
+export using ::beman::execution::nostopstate_t;
+export using ::beman::execution::nostopstate;
+
+// [stopcallback], class template stop_callback
+export using ::beman::execution::stop_callback;
+
+// [stoptoken.never], class never_stop_token
+export using ::beman::execution::never_stop_token;
+
+// [stoptoken.inplace], class inplace_stop_token
+export using ::beman::execution::inplace_stop_token;
+
+// [stopsource.inplace], class inplace_stop_source
+export using ::beman::execution::inplace_stop_source;
+
+// [stopcallback.inplace], class template inplace_stop_callback
+export using ::beman::execution::inplace_stop_callback;
+export using ::beman::execution::stop_callback_for_t;
+
+#if 0
+    //-dk:TODO enable the execution policies
+    export using ::std::is_execution_policy;
+    export using ::std::is_execution_policy_v;
+
+    export using ::std::execution::sequenced_policy;
+    export using ::std::execution::parallel_policy;
+    export using ::std::execution::parallel_unsequenced_policy;
+    export using ::std::execution::unsequenced_policy;
+
+    export using ::std::execution::seq;
+    export using ::std::execution::par;
+    export using ::std::execution::par_unseq;
+    export using ::std::execution::unseq;
+#endif
+
+// [exec.queries], queries
+export using ::beman::execution::forwarding_query_t;
+export using ::beman::execution::get_allocator_t;
+export using ::beman::execution::get_stop_token_t;
+
+export using ::beman::execution::forwarding_query;
+export using ::beman::execution::get_allocator;
+export using ::beman::execution::get_stop_token;
+
+export using ::beman::execution::stop_token_of_t;
+
+export using ::beman::execution::get_domain_t;
+export using ::beman::execution::get_scheduler_t;
+export using ::beman::execution::get_delegation_scheduler_t;
+//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee_t;
+export using ::beman::execution::get_completion_scheduler_t;
+
+export using ::beman::execution::get_domain;
+export using ::beman::execution::get_scheduler;
+export using ::beman::execution::get_delegation_scheduler;
+//-dk:TODO export using ::beman::execution::forward_progress_guarantee;
+//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee;
+export using ::beman::execution::get_completion_scheduler;
+
+export using ::beman::execution::env;
+export using ::beman::execution::get_env_t;
+export using ::beman::execution::get_env;
+
+export using ::beman::execution::env_of_t;
+
+// [exec.domain.default], execution_domains
+export using ::beman::execution::default_domain;
+
+// [exec.sched], schedulers
+export using ::beman::execution::scheduler_t;
+export using ::beman::execution::scheduler;
+
+// [exec.recv], receivers
+export using ::beman::execution::receiver_t;
+export using ::beman::execution::receiver;
+export using ::beman::execution::receiver_of;
+
+export using ::beman::execution::set_value_t;
+export using ::beman::execution::set_error_t;
+export using ::beman::execution::set_stopped_t;
+
+export using ::beman::execution::set_value;
+export using ::beman::execution::set_error;
+export using ::beman::execution::set_stopped;
+
+// [exec.opstate], operation states
+export using ::beman::execution::operation_state_t;
+export using ::beman::execution::operation_state;
+export using ::beman::execution::start_t;
+export using ::beman::execution::start;
+
+// [exec.snd], senders
+export using ::beman::execution::sender_t;
+export using ::beman::execution::sender;
+export using ::beman::execution::sender_in;
+//-dk:TODO export using ::beman::execution::sender_to;
+
+// [exec.getcomplsigs], completion signatures
+export using ::beman::execution::get_completion_signatures_t;
+export using ::beman::execution::get_completion_signatures;
+export using ::beman::execution::completion_signatures_of_t;
+export using ::beman::execution::value_types_of_t;
+export using ::beman::execution::error_types_of_t;
+export using ::beman::execution::sends_stopped;
+export using ::beman::execution::tag_of_t;
+
+// [exec.snd.transform], sender transformations
+export using ::beman::execution::transform_sender;
+
+// [exec.snd.transform.env], environment transformations
+//-dk:TODO export using ::beman::execution::transform_env;
+
+// [exec.snd.apply], sender algorithm application
+export using ::beman::execution::apply_sender;
+
+// [exec.connect], the connect sender algorithm
+export using ::beman::execution::connect_t;
+export using ::beman::execution::connect;
+export using ::beman::execution::connect_result_t;
+
+// [exec.factories], sender factories
+export using ::beman::execution::just_t;
+export using ::beman::execution::just_error_t;
+export using ::beman::execution::just_stopped_t;
+export using ::beman::execution::schedule_t;
+
+export using ::beman::execution::just;
+export using ::beman::execution::just_error;
+export using ::beman::execution::just_stopped;
+export using ::beman::execution::schedule;
+export using ::beman::execution::read_env;
+
+export using ::beman::execution::schedule_result_t;
+
+// [exec.adapt], sender adaptors
+export using ::beman::execution::sender_adaptor_closure;
+
+export using ::beman::execution::starts_on_t;
+export using ::beman::execution::continues_on_t;
+export using ::beman::execution::on_t;
+export using ::beman::execution::schedule_from_t;
+export using ::beman::execution::then_t;
+export using ::beman::execution::upon_error_t;
+export using ::beman::execution::upon_stopped_t;
+export using ::beman::execution::let_value_t;
+export using ::beman::execution::let_error_t;
+export using ::beman::execution::let_stopped_t;
+export using ::beman::execution::bulk_t;
+export using ::beman::execution::split_t;
+export using ::beman::execution::when_all_t;
+export using ::beman::execution::when_all_with_variant_t;
+export using ::beman::execution::into_variant_t;
+//-dk:TODO export using ::beman::execution::stopped_as_optional_t;
+//-dk:TODO export using ::beman::execution::stopped_as_error_t;
+
+export using ::beman::execution::starts_on;
+export using ::beman::execution::continues_on;
+export using ::beman::execution::on;
+export using ::beman::execution::schedule_from;
+export using ::beman::execution::then;
+export using ::beman::execution::upon_error;
+export using ::beman::execution::upon_stopped;
+export using ::beman::execution::let_value;
+export using ::beman::execution::let_error;
+export using ::beman::execution::let_stopped;
+export using ::beman::execution::bulk;
+export using ::beman::execution::split;
+export using ::beman::execution::when_all;
+export using ::beman::execution::when_all_with_variant;
+export using ::beman::execution::into_variant;
+//-dk:TODO export using ::beman::execution::stopped_as_optional;
+//-dk:TODO export using ::beman::execution::stopped_as_error;
+
+// [exec.util.cmplsig]
+export using ::beman::execution::completion_signatures;
+
+// [exec.util.cmplsig.trans]
+//-dk:TODO export using ::beman::execution::transform_completion_signatures;
+//-dk:TODO export using ::beman::execution::transform_completion_signatures_of;
+
+// [exec.run.loop], run_loop
+export using ::beman::execution::run_loop;
+
+// [exec.consumers], consumers
+export using ::beman::execution::sync_wait_t;
+//-dk:TODO export using ::beman::execution::sync_wait_with_variant_t;
+
+export using ::beman::execution::sync_wait;
+//-dk:TODO export using ::beman::execution::sync_wait_with_variant;
+
+// [exec.as.awaitable]
+export using ::beman::execution::as_awaitable_t;
+export using ::beman::execution::as_awaitable;
+
+// [exec.with.awaitable.senders]
+export using ::beman::execution::with_awaitable_senders;
+
+//-dk:TODO add section
+export using ::beman::execution::prop;
+export using ::beman::execution::write_env_t;
+export using ::beman::execution::write_env;
+export using ::beman::execution::affine_on_t;
+export using ::beman::execution::affine_on;
+export using ::beman::execution::read_env_t;
+export using ::beman::execution::read_env;
+export using ::beman::execution::simple_counting_scope;
+export using ::beman::execution::counting_scope;
+export using ::beman::execution::scope_token;
+
+namespace detail {
+export using ::beman::execution::detail::basic_sender;
+export using ::beman::execution::detail::product_type;
+export using ::beman::execution::detail::product_type_base;
+export using ::beman::execution::detail::is_product_type_c;
+export using ::beman::execution::detail::env_promise;
+export using ::beman::execution::detail::await_result_type;
+export using ::beman::execution::detail::simple_allocator;
+export using ::beman::execution::detail::sync_wait_env;
+export using ::beman::execution::detail::sync_wait_result_type;
+export using ::beman::execution::detail::sync_wait_state;
+export using ::beman::execution::detail::sync_wait_receiver;
+export using ::beman::execution::detail::connect_all_t;
+export using ::beman::execution::detail::connect_all;
+} // namespace detail
+
+} // namespace beman::execution
+
+namespace std {
+export template <typename T>
+    requires ::beman::execution::detail::is_product_type_c<T>
+struct tuple_size<T>;
+
+export template <::std::size_t I, typename T>
+    requires ::beman::execution::detail::is_product_type_c<T>
+struct tuple_element<I, T>;
+} // namespace std
diff --git a/src/beman/execution/execution.cppm b/src/beman/execution/execution.cppm
index 0a8d1b17..e54eb38a 100644
--- a/src/beman/execution/execution.cppm
+++ b/src/beman/execution/execution.cppm
@@ -5,242 +5,6468 @@ module;
 // *****************************************************;
 // generated by ./bin/mk-module.py src/beman/execution/execution.cppm
 
-#include <beman/execution/execution.hpp>
-#include <beman/execution/stop_token.hpp>
+#include <beman/execution/modules_export.hpp>
+#include <cassert>
+
+#ifdef BEMAN_HAS_IMPORT_STD
+import std;
+#else
+#line 239 "./bin/mk-module.py"
+#include <algorithm>
+#line 239 "./bin/mk-module.py"
+#include <atomic>
+#line 239 "./bin/mk-module.py"
+#include <cassert>
+#line 239 "./bin/mk-module.py"
+#include <concepts>
+#line 239 "./bin/mk-module.py"
+#include <condition_variable>
+#line 239 "./bin/mk-module.py"
+#include <coroutine>
+#line 239 "./bin/mk-module.py"
+#include <cstddef>
+#line 239 "./bin/mk-module.py"
+#include <cstdlib>
+#line 239 "./bin/mk-module.py"
+#include <exception>
+#line 239 "./bin/mk-module.py"
+#include <functional>
+#line 239 "./bin/mk-module.py"
+#include <memory>
+#line 239 "./bin/mk-module.py"
+#include <mutex>
+#line 239 "./bin/mk-module.py"
+#include <optional>
+#line 239 "./bin/mk-module.py"
+#include <system_error>
+#line 239 "./bin/mk-module.py"
+#include <thread>
+#line 239 "./bin/mk-module.py"
+#include <tuple>
+#line 239 "./bin/mk-module.py"
+#include <type_traits>
+#line 239 "./bin/mk-module.py"
+#include <utility>
+#line 239 "./bin/mk-module.py"
+#include <variant>
+#endif
 
 export module beman.execution;
 
-namespace beman::execution
-{
-export using beman::execution::detail::pipeable::operator|;
+#line 5 "include/beman/execution/execution.hpp"
+
+#line 9 "include/beman/execution/detail/common.hpp"
+#ifndef BEMAN_EXECUTION_EXPORT
+#define BEMAN_EXECUTION_EXPORT
+#endif
+
+#if defined(disabled__cpp_deleted_function)
+#define BEMAN_EXECUTION_DELETE(msg) delete (msg)
+#else
+#define BEMAN_EXECUTION_DELETE(msg) delete
+#endif
+
+#line 43 "include/beman/execution/detail/common.hpp"
+namespace beman {
+
+#line 54 "include/beman/execution/detail/common.hpp"
+namespace execution {
+
+#line 61 "include/beman/execution/detail/common.hpp"
+namespace detail {}
+} // namespace execution
+} // namespace beman
+
+#line 6 "include/beman/execution/detail/suppress_push.hpp"
+#if defined(__GNUC__)
+#define BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-braces"
+#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
+#endif
+
+#if defined(__clang__)
+#define BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunknown-warning-option"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+#pragma clang diagnostic ignored "-Wc++26-extensions"
+#endif
+#line 3 "include/beman/execution/detail/suppress_pop.hpp"
+
+#line 6 "include/beman/execution/detail/suppress_pop.hpp"
+#ifdef BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
+#if defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+#undef BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
+#endif
+#line 3 "include/beman/execution/detail/queryable.hpp"
+
+#line 12 "include/beman/execution/detail/queryable.hpp"
+namespace beman::execution::detail {
+template <typename T>
+concept queryable = ::std::destructible<T>;
+}
+#line 14 "include/beman/execution/detail/forwarding_query.hpp"
+namespace beman::execution::detail {
+
+#line 20 "include/beman/execution/detail/forwarding_query.hpp"
+struct forwarding_query_t {
+    template <typename Object>
+        requires requires(Object&& object, const forwarding_query_t& query) {
+            { ::std::forward<Object>(object).query(query) } noexcept -> ::std::same_as<bool>;
+        }
+    constexpr auto operator()(Object&& object) const noexcept -> bool {
+        return ::std::forward<Object>(object).query(*this);
+    }
+    template <typename Object>
+    constexpr auto operator()(Object&&) const noexcept -> bool {
+        return ::std::derived_from<::std::remove_cvref_t<Object>, ::beman::execution::detail::forwarding_query_t>;
+    }
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+
+#line 40 "include/beman/execution/detail/forwarding_query.hpp"
+export /* --------- */ using forwarding_query_t = beman::execution::detail::forwarding_query_t;
+
+#line 53 "include/beman/execution/detail/forwarding_query.hpp"
+export /* --------- */ inline constexpr forwarding_query_t forwarding_query{};
+} // namespace beman::execution
+
+#line 13 "include/beman/execution/detail/movable_value.hpp"
+namespace beman::execution::detail {
+template <typename T>
+concept movable_value =
+    ::std::move_constructible<::std::decay_t<T>> && ::std::constructible_from<::std::decay_t<T>, T> &&
+    (!::std::is_array_v<::std::remove_reference_t<T>>);
+}
+#line 12 "include/beman/execution/detail/matching_sig.hpp"
+namespace beman::execution::detail {
+template <typename Fun>
+struct matching_sig_transform {
+    using type = Fun;
+};
+template <typename Return, typename... Args>
+struct matching_sig_transform<Return(Args...)> {
+    using type = Return(Args&&...);
+};
+
+template <typename Fun1, typename Fun2>
+inline constexpr bool matching_sig =
+    ::std::same_as<typename ::beman::execution::detail::matching_sig_transform<Fun1>::type,
+                   typename ::beman::execution::detail::matching_sig_transform<Fun2>::type>;
+} // namespace beman::execution::detail
+
+#line 17 "include/beman/execution/detail/as_except_ptr.hpp"
+namespace beman::execution::detail {
+
+#line 23 "include/beman/execution/detail/as_except_ptr.hpp"
+template <typename Error>
+decltype(auto) as_except_ptr(Error&& error) {
+    if constexpr (::std::same_as<::std::exception_ptr, ::std::decay_t<Error>>) {
+        return ::std::forward<Error>(error);
+    } else if constexpr (::std::same_as<::std::error_code, ::std::decay_t<Error>>) {
+        return ::std::make_exception_ptr(::std::system_error(error));
+    } else {
+        return ::std::make_exception_ptr(::std::forward<Error>(error));
+    }
+}
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/set_value.hpp"
+namespace beman::execution {
+
+#line 19 "include/beman/execution/detail/set_value.hpp"
+export /* --------- */ struct set_value_t {
+    template <typename Receiver, typename... Args>
+    auto operator()(Receiver&, Args&&...) const
+        -> void = BEMAN_EXECUTION_DELETE("set_value requires the receiver to be passed as non-const rvalue");
+    template <typename Receiver, typename... Args>
+    auto operator()(const Receiver&&, Args&&...) const
+        -> void = BEMAN_EXECUTION_DELETE("set_value requires the receiver to be passed as non-const rvalue");
+    template <typename Receiver, typename... Args>
+    auto operator()(Receiver&&, Args&&...) const -> void
+        requires(not requires(Receiver&& receiver, Args&&... args) {
+                    ::std::forward<Receiver>(receiver).set_value(::std::forward<Args>(args)...);
+                })
+    = BEMAN_EXECUTION_DELETE("set_value requires a suitable member overload on the receiver");
+    template <typename Receiver, typename... Args>
+        requires(not noexcept(::std::declval<Receiver>().set_value(::std::declval<Args>()...)))
+    auto operator()(Receiver&&, Args&&...) const
+        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_value(args...) has to be noexcept");
+
+    template <typename Receiver, typename... Args>
+    auto operator()(Receiver&& receiver, Args&&... args) const noexcept -> void {
+        ::std::forward<Receiver>(receiver).set_value(::std::forward<Args>(args)...);
+    }
+};
+
+#line 47 "include/beman/execution/detail/set_value.hpp"
+export /* --------- */ inline constexpr set_value_t set_value{};
+} // namespace beman::execution
+
+#line 14 "include/beman/execution/detail/set_error.hpp"
+namespace beman::execution {
+
+#line 19 "include/beman/execution/detail/set_error.hpp"
+export /* --------- */ struct set_error_t {
+    template <typename Receiver, typename Error>
+    auto operator()(Receiver&, Error&&) const
+        -> void = BEMAN_EXECUTION_DELETE("set_error requires the receiver to be passed as non-const rvalue");
+    template <typename Receiver, typename Error>
+    auto operator()(const Receiver&&, Error&&) const
+        -> void = BEMAN_EXECUTION_DELETE("set_error requires the receiver to be passed as non-const rvalue");
+    template <typename Receiver, typename Error>
+    auto operator()(Receiver&&, Error&&) const -> void
+        requires(not requires(Receiver&& receiver, Error&& error) {
+                    ::std::forward<Receiver>(receiver).set_error(::std::forward<Error>(error));
+                })
+    = BEMAN_EXECUTION_DELETE("set_error requires a suitable member overload on the receiver");
+    template <typename Receiver, typename Error>
+        requires(not noexcept(::std::declval<Receiver>().set_error(::std::declval<Error>())))
+    auto operator()(Receiver&&, Error&&) const
+        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_error(error) has to be noexcept");
+
+    // NOLINTBEGIN(misc-no-recursion)
+    template <typename Receiver, typename Error>
+    auto operator()(Receiver&& receiver, Error&& error) const noexcept -> void {
+        ::std::forward<Receiver>(receiver).set_error(::std::forward<Error>(error));
+    }
+    // NOLINTEND(misc-no-recursion)
+};
+
+#line 49 "include/beman/execution/detail/set_error.hpp"
+export /* --------- */ inline constexpr set_error_t set_error{};
+} // namespace beman::execution
+
+#line 14 "include/beman/execution/detail/set_stopped.hpp"
+namespace beman::execution {
+
+#line 19 "include/beman/execution/detail/set_stopped.hpp"
+export /* --------- */ struct set_stopped_t {
+    template <typename Receiver>
+    auto operator()(Receiver&) const
+        -> void = BEMAN_EXECUTION_DELETE("set_stopped requires the receiver to be passed as non-const rvalue");
+    template <typename Receiver>
+    auto operator()(const Receiver&&) const
+        -> void = BEMAN_EXECUTION_DELETE("set_stopped requires the receiver to be passed as non-const rvalue");
+    template <typename Receiver>
+    auto operator()(Receiver&&) const -> void
+        requires(not requires(Receiver&& receiver) { ::std::forward<Receiver>(receiver).set_stopped(); })
+    = BEMAN_EXECUTION_DELETE("set_stopped requires a suitable member overload on the receiver");
+    template <typename Receiver>
+        requires(not noexcept(::std::declval<Receiver>().set_stopped()))
+    auto operator()(Receiver&&) const
+        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_stopped() has to be noexcept");
+
+    template <typename Receiver>
+    auto operator()(Receiver&& receiver) const noexcept -> void {
+        ::std::forward<Receiver>(receiver).set_stopped();
+    }
+};
+
+#line 45 "include/beman/execution/detail/set_stopped.hpp"
+export /* --------- */ inline constexpr set_stopped_t set_stopped{};
+} // namespace beman::execution
+
+#line 13 "include/beman/execution/detail/start.hpp"
+namespace beman::execution {
+export /* --------- */ struct start_t {
+    template <typename State>
+    auto operator()(State&&) const -> void = BEMAN_EXECUTION_DELETE("start(obj) requires an lvalue argument");
+    template <typename State>
+        requires(not requires(State& state) { state.start(); })
+    auto operator()(State&) const -> void = BEMAN_EXECUTION_DELETE("state needs to have a start() member");
+    template <typename State>
+        requires(not requires(const State& state) { state.start(); })
+    auto operator()(const State&) const -> void = BEMAN_EXECUTION_DELETE("state needs to have a start() member");
+
+    template <typename State>
+        requires(not requires(State& state) {
+                    { state.start() } noexcept;
+                })
+    auto operator()(State&) const -> void = BEMAN_EXECUTION_DELETE("state start() member has to be noexcept");
+    template <typename State>
+        requires(not requires(const State& state) {
+                    { state.start() } noexcept;
+                })
+    auto operator()(const State&) const -> void = BEMAN_EXECUTION_DELETE("state start() member has to be noexcept");
+
+    template <typename State>
+    auto operator()(const State& state) const noexcept -> void {
+        state.start();
+    }
+    // NOLINTBEGIN(misc-no-recursion)
+    template <typename State>
+    auto operator()(State& state) const noexcept -> void {
+        state.start();
+    }
+    // NOLINTEND(misc-no-recursion)
+};
+
+export /* --------- */ inline constexpr start_t start{};
+} // namespace beman::execution
+
+#line 11 "include/beman/execution/detail/non_assignable.hpp"
+namespace beman::execution::detail {
+struct non_assignable;
+}
+#line 17 "include/beman/execution/detail/non_assignable.hpp"
+struct beman::execution::detail::non_assignable {
+    non_assignable()                                         = default;
+    non_assignable(non_assignable&&)                         = default;
+    non_assignable(const non_assignable&)                    = default;
+    auto operator=(non_assignable&&) -> non_assignable&      = delete;
+    auto operator=(const non_assignable&) -> non_assignable& = delete;
+};
+
+#line 13 "include/beman/execution/detail/simple_allocator.hpp"
+namespace beman::execution::detail {
+export /* --------- */ template <typename Alloc>
+concept simple_allocator =
+    requires(::std::remove_cvref_t<Alloc> alloc, ::std::size_t n) {
+        { *alloc.allocate(n) } -> ::std::same_as<typename ::std::remove_cvref_t<Alloc>::value_type&>;
+        alloc.deallocate(alloc.allocate(n), n);
+    } && ::std::copy_constructible<::std::remove_cvref_t<Alloc>> &&
+    ::std::equality_comparable<::std::remove_cvref_t<Alloc>>;
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/never_stop_token.hpp"
+namespace beman::execution {
+export /* --------- */ class never_stop_token;
+}
+#line 17 "include/beman/execution/detail/never_stop_token.hpp"
+class beman::execution::never_stop_token {
+    struct private_callback_type {
+        explicit private_callback_type(never_stop_token, auto&&) noexcept {}
+    };
+
+  public:
+    template <typename>
+    using callback_type = private_callback_type;
+
+    static constexpr auto stop_requested() noexcept -> bool { return {}; }
+    static constexpr auto stop_possible() noexcept -> bool { return {}; }
+    auto                  operator==(const never_stop_token&) const -> bool = default;
+};
+
+#line 12 "include/beman/execution/detail/decayed_same_as.hpp"
+namespace beman::execution::detail {
+
+#line 19 "include/beman/execution/detail/decayed_same_as.hpp"
+template <typename T0, typename T1>
+concept decayed_same_as = ::std::same_as<::std::remove_cvref_t<T0>, ::std::remove_cvref_t<T1>>;
+} // namespace beman::execution::detail
+
+#line 12 "include/beman/execution/detail/callable.hpp"
+namespace beman::execution::detail {
+
+#line 19 "include/beman/execution/detail/callable.hpp"
+template <typename Fun, typename... Args>
+concept callable = requires(Fun&& fun, Args&&... args) { ::std::forward<Fun>(fun)(::std::forward<Args>(args)...); };
+} // namespace beman::execution::detail
+
+#line 15 "include/beman/execution/detail/forward_like.hpp"
+namespace beman::execution::detail {
+template <typename>
+struct forward_like_helper;
+
+template <typename T>
+struct forward_like_helper {
+    template <typename U>
+    static auto forward(U&& u) -> ::std::remove_reference_t<U>&& {
+        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
+    }
+};
+template <typename T>
+struct forward_like_helper<T&&> {
+    template <typename U>
+    static auto forward(U&& u) -> ::std::remove_cvref_t<U>&& {
+        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
+    }
+};
+template <typename T>
+struct forward_like_helper<T&> {
+    template <typename U>
+    static auto forward(U&& u) -> ::std::remove_cvref_t<U>& {
+        return ::std::forward<U&&>(u);
+    }
+};
+template <typename T>
+struct forward_like_helper<const T&&> {
+    template <typename U>
+    static auto forward(U&& u) -> const ::std::remove_cvref_t<U>&& {
+        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
+    }
+};
+template <typename T>
+struct forward_like_helper<const T&> {
+    template <typename U>
+    static auto forward(U&& u) -> const ::std::remove_cvref_t<U>& {
+        return ::std::forward<U&&>(u);
+    }
+};
+
+#line 57 "include/beman/execution/detail/forward_like.hpp"
+template <typename T, typename U>
+auto own_forward_like(U&& u) noexcept -> decltype(auto) {
+    return ::beman::execution::detail::forward_like_helper<T>::forward(::std::forward<U>(u));
+}
+#line 67 "include/beman/execution/detail/forward_like.hpp"
+template <typename T, typename U>
+auto forward_like(U&& u) noexcept -> decltype(auto) {
+#if 202207 <= disabled__cpp_lib_forward_like
+    return ::std::forward_like<T>(::std::forward<U>(u));
+#else
+    return ::beman::execution::detail::forward_like_helper<T>::forward(::std::forward<U>(u));
+#endif
+}
+#line 76 "include/beman/execution/detail/forward_like.hpp"
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/join_env.hpp"
+namespace beman::execution::detail {
+template <typename Env1, typename Env2>
+class join_env {
+  private:
+    Env1 env1;
+    Env2 env2;
+
+  public:
+    template <typename E1, typename E2>
+    join_env(E1&& e1, E2&& e2) : env1(::std::forward<E1>(e1)), env2(::std::forward<E2>(e2)) {}
+
+    template <typename Query, typename... Args>
+        requires requires(Env1&, const Query& query, Args&&... args) {
+            env1.query(query, ::std::forward<Args>(args)...);
+        }
+    auto query(const Query& query, Args&&... args) noexcept -> decltype(auto) {
+        return this->env1.query(query, ::std::forward<Args>(args)...);
+    }
+    template <typename Query, typename... Args>
+        requires(
+            not requires(Env1&, const Query& query, Args&&... args) {
+                env1.query(query, ::std::forward<Args>(args)...);
+            } &&
+            requires(Env2& e2, const Query& query, Args&&... args) { e2.query(query, ::std::forward<Args>(args)...); })
+    auto query(const Query& query, Args&&... args) noexcept -> decltype(auto) {
+        return this->env2.query(query, ::std::forward<Args>(args)...);
+    }
+    template <typename Query, typename... Args>
+        requires requires(const Env1& e1, const Query& query, Args&&... args) {
+            { e1.query(query, ::std::forward<Args>(args)...) } noexcept;
+        }
+    auto query(const Query& query, Args&&... args) const noexcept -> decltype(auto) {
+        return this->env1.query(query, ::std::forward<Args>(args)...);
+    }
+    template <typename Query, typename... Args>
+        requires(
+            not requires(const Env1& e1, const Query& query, Args&&... args) {
+                { e1.query(query, ::std::forward<Args>(args)...) } noexcept;
+            } &&
+            requires(const Env2& e2, const Query& query, Args&&... args) {
+                { e2.query(query, ::std::forward<Args>(args)...) } noexcept;
+            })
+    auto query(const Query& query, Args&&... args) const noexcept -> decltype(auto) {
+        return this->env2.query(query, ::std::forward<Args>(args)...);
+    }
+};
 
-// [stoptoken.concepts], stop token concepts
-export using ::beman::execution::stoppable_token;
-export using ::beman::execution::unstoppable_token;
+template <typename Env1, typename Env2>
+join_env(Env1&&, Env2&&) -> join_env<::std::remove_cvref_t<Env1>, ::std::remove_cvref_t<Env2>>;
+} // namespace beman::execution::detail
 
-// [stoptoken], class stop_token
-export using ::beman::execution::stop_token;
+#line 15 "include/beman/execution/detail/product_type.hpp"
+namespace beman::execution::detail {
 
-// [stopsource], class stop_source
-export using ::beman::execution::stop_source;
+template <::std::size_t I, typename T>
+struct product_type_element {
+    T    value;
+    auto operator==(const product_type_element&) const -> bool = default;
+};
 
-export using ::beman::execution::nostopstate_t;
-export using ::beman::execution::nostopstate;
+template <typename, typename...>
+struct product_type_base;
 
-// [stopcallback], class template stop_callback
-export using ::beman::execution::stop_callback;
+template <::std::size_t... I, typename... T>
+struct product_type_base<::std::index_sequence<I...>, T...>
+    : ::beman::execution::detail::product_type_element<I, T>... {
+    static constexpr ::std::size_t size() { return sizeof...(T); }
+    static constexpr bool          is_product_type{true};
 
-// [stoptoken.never], class never_stop_token
-export using ::beman::execution::never_stop_token;
+    template <::std::size_t J, typename S>
+    static auto element_get(::beman::execution::detail::product_type_element<J, S>& self) noexcept -> S& {
+        return self.value;
+    }
+    template <::std::size_t J, typename S>
+    static auto element_get(::beman::execution::detail::product_type_element<J, S>&& self) noexcept -> S&& {
+        return ::std::move(self.value);
+    }
+    template <::std::size_t J, typename S>
+    static auto element_get(const ::beman::execution::detail::product_type_element<J, S>& self) noexcept -> const S& {
+        return self.value;
+    }
+#line 45 "include/beman/execution/detail/product_type.hpp"
+    template <::std::size_t J>
+    auto get() & -> decltype(auto) {
+        return this->element_get<J>(*this);
+    }
+    template <::std::size_t J>
+    auto get() && -> decltype(auto) {
+        return this->element_get<J>(::std::move(*this));
+    }
+    template <::std::size_t J>
+    auto get() const& -> decltype(auto) {
+        return this->element_get<J>(*this);
+    }
+#line 58 "include/beman/execution/detail/product_type.hpp"
+    template <::std::size_t J, typename Allocator, typename Self>
+    static auto make_element(Allocator&& alloc, Self&& self) -> decltype(auto) {
+        using type = ::std::remove_cvref_t<decltype(product_type_base::element_get<J>(std::forward<Self>(self)))>;
+        if constexpr (::std::uses_allocator_v<type, Allocator>)
+            return ::std::make_obj_using_allocator<type>(alloc,
+                                                         product_type_base::element_get<J>(std::forward<Self>(self)));
+        else
+            return product_type_base::element_get<J>(std::forward<Self>(self));
+    }
+#line 68 "include/beman/execution/detail/product_type.hpp"
+    auto operator==(const product_type_base&) const -> bool = default;
+};
 
-// [stoptoken.inplace], class inplace_stop_token
-export using ::beman::execution::inplace_stop_token;
+template <typename T>
+concept is_product_type_c = requires(const T& t) { T::is_product_type; };
 
-// [stopsource.inplace], class inplace_stop_source
-export using ::beman::execution::inplace_stop_source;
+template <typename... T>
+struct product_type : ::beman::execution::detail::product_type_base<::std::index_sequence_for<T...>, T...> {
+    template <typename Allocator, typename Product, std::size_t... I>
+    static auto make_from(Allocator&& allocator, Product&& product, std::index_sequence<I...>) -> product_type {
+        return {product_type::template make_element<I>(allocator, ::std::forward<Product>(product))...};
+    }
+#line 81 "include/beman/execution/detail/product_type.hpp"
+    template <typename Allocator, typename Product>
+    static auto make_from(Allocator&& allocator, Product&& product) -> product_type {
+        return product_type::make_from(
+            ::std::forward<Allocator>(allocator), ::std::forward<Product>(product), ::std::index_sequence_for<T...>{});
+    }
+#line 87 "include/beman/execution/detail/product_type.hpp"
+    template <typename Fun, ::std::size_t... I>
+    constexpr auto apply_elements(::std::index_sequence<I...>, Fun&& fun) const -> decltype(auto) {
+        return ::std::forward<Fun>(fun)(this->template get<I>()...);
+    }
+    template <typename Fun>
+    constexpr auto apply(Fun&& fun) const -> decltype(auto) {
+        return apply_elements(::std::index_sequence_for<T...>{}, ::std::forward<Fun>(fun));
+    }
+    template <typename Fun, ::std::size_t... I>
+    constexpr auto apply_elements(::std::index_sequence<I...>, Fun&& fun) -> decltype(auto) {
 
-// [stopcallback.inplace], class template inplace_stop_callback
-export using ::beman::execution::inplace_stop_callback;
-export using ::beman::execution::stop_callback_for_t;
+        return ::std::forward<Fun>(fun)(std::move(this->template get<I>())...);
+    }
+    template <typename Fun>
+    constexpr auto apply(Fun&& fun) -> decltype(auto) {
+        return apply_elements(::std::index_sequence_for<T...>{}, ::std::forward<Fun>(fun));
+    }
+};
+template <typename... T>
+product_type(T&&...) -> product_type<::std::decay_t<T>...>;
 
+template <typename T>
+constexpr auto is_product_type(const T&) -> ::std::false_type {
+    return {};
+}
+template <typename... T>
+constexpr auto is_product_type(const ::beman::execution::detail::product_type<T...>&) -> ::std::true_type {
+    return {};
+}
+#line 117 "include/beman/execution/detail/product_type.hpp"
+template <::std::size_t Start, typename Fun, typename Tuple, ::std::size_t... I>
+constexpr auto sub_apply_helper(Fun&& fun, Tuple&& tuple, ::std::index_sequence<I...>) -> decltype(auto) {
+    // NOLINTNEXTLINE(bugprone-use-after-move,hicpp-invalid-access-moved)
+    return ::std::forward<Fun>(fun)(::std::forward<Tuple>(tuple).template get<I + Start>()...);
+}
+#line 123 "include/beman/execution/detail/product_type.hpp"
+template <::std::size_t Start, typename Fun, typename Tuple>
+constexpr auto sub_apply(Fun&& fun, Tuple&& tuple) -> decltype(auto) {
+    constexpr ::std::size_t TSize{::std::tuple_size_v<::std::remove_cvref_t<Tuple>>};
+    static_assert(Start <= TSize);
+    return sub_apply_helper<Start>(
+        ::std::forward<Fun>(fun), ::std::forward<Tuple>(tuple), ::std::make_index_sequence<TSize - Start>());
+}
+#line 131 "include/beman/execution/detail/product_type.hpp"
+} // namespace beman::execution::detail
+
+namespace std {
+template <typename T>
+    requires ::beman::execution::detail::is_product_type_c<T>
+struct tuple_size<T> : ::std::integral_constant<std::size_t, T::size()> {};
+
+template <::std::size_t I, typename T>
+    requires ::beman::execution::detail::is_product_type_c<T>
+struct tuple_element<I, T> {
+    using type = ::std::decay_t<decltype(::std::declval<T>().template get<I>())>;
+};
+} // namespace std
+
+#line 12 "include/beman/execution/detail/query_with_default.hpp"
+namespace beman::execution::detail {
+template <typename Tag, typename Env, typename Value>
+    requires requires(const Tag& tag, const Env& env) { tag(env); }
+constexpr auto query_with_default(Tag, const Env& env, Value&&) noexcept(noexcept(Tag()(env))) -> decltype(auto) {
+    return Tag()(env);
+}
+#line 19 "include/beman/execution/detail/query_with_default.hpp"
+template <typename Tag, typename Env, typename Value>
+constexpr auto
+query_with_default(Tag, const Env&, Value&& value) noexcept(noexcept(static_cast<Value>(std::forward<Value>(value))))
+    -> decltype(auto) {
+    return static_cast<Value>(std::forward<Value>(value));
+}
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/child_type.hpp"
+namespace beman::execution::detail {
+
+#line 19 "include/beman/execution/detail/child_type.hpp"
+template <typename Sender, ::std::size_t I = 0u>
+using child_type = decltype(::std::declval<Sender>().template get<I + 2>());
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/decayed_tuple.hpp"
+namespace beman::execution::detail {
+
+#line 19 "include/beman/execution/detail/decayed_tuple.hpp"
+template <typename... T>
+using decayed_tuple = ::std::tuple<::std::decay_t<T>...>;
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/make_env.hpp"
+namespace beman::execution::detail {
+export /* --------- */ template <typename Query, typename Value>
+class make_env {
+  private:
+    Value value;
+
+  public:
+    template <typename V>
+    make_env(const Query&, V&& v) : value(::std::forward<V>(v)) {}
+    constexpr auto query(const Query&) const noexcept -> const Value& { return this->value; }
+    constexpr auto query(const Query&) noexcept -> Value& { return this->value; }
+};
+template <typename Query, typename Value>
+make_env(Query&&, Value&& value) -> make_env<::std::remove_cvref_t<Query>, ::std::remove_cvref_t<Value>>;
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/meta_prepend.hpp"
+namespace beman::execution::detail::meta::detail {
+template <typename, typename>
+struct prepend;
+
+template <template <typename...> class List, typename H, typename... T>
+struct prepend<H, List<T...>> {
+    using type = List<H, T...>;
+};
+} // namespace beman::execution::detail::meta::detail
+
+namespace beman::execution::detail::meta {
+template <typename H, typename Tail>
+using prepend = typename ::beman::execution::detail::meta::detail::prepend<H, Tail>::type;
+}
+#line 11 "include/beman/execution/detail/meta_to.hpp"
+namespace beman::execution::detail::meta {
+template <template <typename...> class To, typename>
+struct to_type_list;
+template <template <typename...> class To, template <typename...> class List, typename... T>
+struct to_type_list<To, List<T...>> {
+    using type = To<T...>;
+};
+template <template <typename...> class To, typename T>
+using to = typename ::beman::execution::detail::meta::to_type_list<To, T>::type;
+} // namespace beman::execution::detail::meta
+
+#line 11 "include/beman/execution/detail/type_list.hpp"
+namespace beman::execution::detail {
+template <typename...>
+struct type_list {};
+} // namespace beman::execution::detail
+
+#line 12 "include/beman/execution/detail/stop_callback_for_t.hpp"
+namespace beman::execution {
+export /* --------- */ template <class Token, class CallbackFun>
+using stop_callback_for_t = typename Token::template callback_type<CallbackFun>;
+}
+#line 17 "include/beman/execution/detail/stop_callback_for_t.hpp"
+namespace beman::execution::detail {
+template <typename CallbackFun, typename Token, typename Initializer = CallbackFun>
+concept stoppable_callback_for =
+    ::std::invocable<CallbackFun> && ::std::constructible_from<CallbackFun, Initializer> &&
+    requires { typename ::beman::execution::stop_callback_for_t<Token, CallbackFun>; } &&
+    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, Token, Initializer> &&
+    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, Token&, Initializer> &&
+    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, const Token&, Initializer>;
+} // namespace beman::execution::detail
+
+#line 12 "include/beman/execution/detail/call_result_t.hpp"
+namespace beman::execution::detail {
+template <typename Fun, typename... Args>
+
+#line 19 "include/beman/execution/detail/call_result_t.hpp"
+using call_result_t = decltype(::std::declval<Fun>()(std::declval<Args>()...));
+} // namespace beman::execution::detail
+#line 12 "include/beman/execution/detail/meta_size.hpp"
+namespace beman::execution::detail::meta {
+template <typename>
+struct size;
+template <template <typename...> class L, typename... T>
+struct size<L<T...>> {
+    static constexpr ::std::size_t value{sizeof...(T)};
+};
+template <typename T>
+inline constexpr ::std::size_t size_v{::beman::execution::detail::meta::size<T>::value};
+} // namespace beman::execution::detail::meta
+
+#line 11 "include/beman/execution/detail/on_stop_request.hpp"
+namespace beman::execution::detail {
+template <typename St>
+struct on_stop_request {
+    St&  st;
+    auto operator()() const -> void { this->st.request_stop(); }
+};
+template <typename T>
+on_stop_request(T&) -> on_stop_request<T>;
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/check_type_alias_exist.hpp"
+namespace beman::execution::detail {
+
+#line 17 "include/beman/execution/detail/check_type_alias_exist.hpp"
+template <template <typename> class>
+struct check_type_alias_exist;
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/scheduler_t.hpp"
+namespace beman::execution {
+
+#line 16 "include/beman/execution/detail/scheduler_t.hpp"
+export /* --------- */ struct scheduler_t {};
+} // namespace beman::execution
+
+#line 12 "include/beman/execution/detail/get_awaiter.hpp"
+namespace beman::execution::detail {
+template <typename Expr, typename Promise>
+auto get_awaiter(Expr&& expr, Promise& promise) -> decltype(auto) {
+    auto transform{[&]() -> decltype(auto) {
+        if constexpr (requires { promise.await_transform(::std::forward<Expr>(expr)); })
+            return promise.await_transform(::std::forward<Expr>(expr));
+        else
+            return ::std::forward<Expr>(expr);
+    }};
+    if constexpr (requires { operator co_await(transform()); }) {
+
+        static_assert(not requires { transform().operator co_await(); }, "only one operator co_await is allowed");
+        return operator co_await(transform());
+    } else if constexpr (requires { transform().operator co_await(); })
+        return transform().operator co_await();
+    else
+        return transform();
+}
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/sender_decompose.hpp"
+namespace beman::execution::detail {
+struct sender_convert_to_any_t {
+    template <typename T>
+    constexpr operator T() const; // NOLINT(hicpp-explicit-conversions)
+};
+
+template <typename Tag, typename Data, typename Children>
+struct sender_meta {
+    using tag_type      = ::std::remove_cvref_t<Tag>;
+    using data_type     = ::std::remove_cvref_t<Data>;
+    using children_type = ::std::remove_cvref_t<Children>;
+};
+
+template <typename Tag, typename Data, typename Children>
+struct sender_data {
+    using tag_type      = ::std::remove_cvref_t<Tag>;
+    using data_type     = ::std::remove_cvref_t<Data>;
+    using children_type = ::std::remove_cvref_t<Children>;
+
+    tag_type tag;
+    Data&    data;
+    Children children;
+};
+template <typename Tag, typename Data, typename Children>
+sender_data(Tag&&, Data&, Children&&) -> sender_data<Tag, Data, Children>;
+
+template <typename Sender>
+auto get_sender_data(Sender&& sender) {
 #if 0
-    //-dk:TODO enable the execution policies
-    export using ::std::is_execution_policy;
-    export using ::std::is_execution_policy_v;
-
-    export using ::std::execution::sequenced_policy;
-    export using ::std::execution::parallel_policy;
-    export using ::std::execution::parallel_unsequenced_policy;
-    export using ::std::execution::unsequenced_policy;
-
-    export using ::std::execution::seq;
-    export using ::std::execution::par;
-    export using ::std::execution::par_unseq;
-    export using ::std::execution::unseq;
+
+        auto&& [tag, data, ... children] = sender;
+        return sender_meta<decltype(tag), decltype(data), ::std::tuple<decltype(children)...>>;
+#else
+    using sender_type = ::std::remove_cvref_t<Sender>;
+    static constexpr ::beman::execution::detail::sender_convert_to_any_t at{};
+
+    if constexpr (requires {
+                      sender.template get<0>();
+                      sender.size();
+                  })
+        return [&sender]<::std::size_t... I>(::std::index_sequence<I...>) {
+            return ::beman::execution::detail::sender_data{
+                sender.template get<0>(), sender.template get<1>(), ::std::tie(sender.template get<2 + I>()...)};
+        }(::std::make_index_sequence<::std::decay_t<decltype(sender)>::size() - 2u>{});
+    else if constexpr (requires { sender_type{at, at, at, at, at, at}; }) {
+        auto&& [tag, data, c0, c1, c2, c3] = sender;
+        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1, c2, c3)};
+    } else if constexpr (requires { sender_type{at, at, at, at, at}; }) {
+        auto&& [tag, data, c0, c1, c2] = sender;
+        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1, c2)};
+    } else if constexpr (requires { sender_type{at, at, at, at}; }) {
+        auto&& [tag, data, c0, c1] = sender;
+        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1)};
+    } else if constexpr (requires { sender_type{at, at, at}; }) {
+        auto&& [tag, data, c0] = sender;
+        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0)};
+    } else if constexpr (requires { sender_type{at, at}; }) {
+        auto&& [tag, data] = sender;
+        return ::beman::execution::detail::sender_data{tag, data, ::std::tuple<>{}};
+    } else {
+        return ::beman::execution::detail::sender_meta<void, void, void>{};
+    }
+#endif
+}
+#line 79 "include/beman/execution/detail/sender_decompose.hpp"
+template <typename Sender>
+auto get_sender_meta(Sender&& sender) {
+    using type = decltype(get_sender_data(sender));
+    return sender_meta<typename type::tag_type, typename type::data_type, typename type::children_type>{};
+}
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/suspend_complete.hpp"
+namespace beman::execution::detail {
+template <typename Fun, typename... Args>
+auto suspend_complete(Fun fun, Args&&... args) noexcept {
+    auto f{[&, fun]() noexcept { fun(::std::forward<Args>(args)...); }};
+    struct awaiter {
+        decltype(f) fun;
+
+        static constexpr auto await_ready() noexcept -> bool { return false; }
+        auto                  await_suspend(::std::coroutine_handle<>) noexcept { this->fun(); }
+#if __cpp_lib_unreachable < 202202L
+        [[noreturn]] auto await_resume() noexcept -> void { ::std::terminate(); }
+#else
+        [[noreturn]] auto await_resume() noexcept -> void { ::std::unreachable(); }
+#endif
+    };
+    return awaiter{f};
+}
+} // namespace beman::execution::detail
+
+#line 12 "include/beman/execution/detail/meta_contains.hpp"
+namespace beman::execution::detail::meta {
+template <typename T, typename... S>
+inline constexpr bool contains{(::std::same_as<T, S> || ...)};
+}
+#line 13 "include/beman/execution/detail/decays_to.hpp"
+namespace beman::execution::detail {
+
+#line 19 "include/beman/execution/detail/decays_to.hpp"
+template <typename From, typename To>
+concept decays_to = ::std::same_as<::std::decay_t<From>, To>;
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/intrusive_stack.hpp"
+namespace beman::execution::detail {
+
+template <auto Next>
+class atomic_intrusive_stack;
+
+template <auto Next>
+class intrusive_stack;
+
+#line 20 "include/beman/execution/detail/intrusive_stack.hpp"
+template <class Item, Item* Item::* Next>
+class intrusive_stack<Next> {
+  public:
+#line 24 "include/beman/execution/detail/intrusive_stack.hpp"
+    auto push(Item* item) noexcept -> void { item->*Next = std::exchange(head_, item); }
+
+#line 29 "include/beman/execution/detail/intrusive_stack.hpp"
+    auto pop() noexcept -> Item* {
+        if (head_) {
+            auto item = head_;
+            head_     = std::exchange(item->*Next, nullptr);
+            return item;
+        }
+        return nullptr;
+    }
+#line 39 "include/beman/execution/detail/intrusive_stack.hpp"
+    auto empty() const noexcept -> bool { return !head_; }
+
+  private:
+    friend class atomic_intrusive_stack<Next>;
+    Item* head_{nullptr};
+};
+
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/immovable.hpp"
+namespace beman::execution::detail {
+struct immovable;
+struct virtual_immovable;
+} // namespace beman::execution::detail
+
+struct beman::execution::detail::immovable {
+    constexpr immovable()                          = default;
+    immovable(immovable&&)                         = delete;
+    immovable(const immovable&)                    = delete;
+    ~immovable()                                   = default;
+    auto operator=(immovable&&) -> immovable&      = delete;
+    auto operator=(const immovable&) -> immovable& = delete;
+};
+
+struct beman::execution::detail::virtual_immovable {
+    constexpr virtual_immovable()                                  = default;
+    virtual_immovable(virtual_immovable&&)                         = delete;
+    virtual_immovable(const virtual_immovable&)                    = delete;
+    virtual ~virtual_immovable()                                   = default;
+    auto operator=(virtual_immovable&&) -> virtual_immovable&      = delete;
+    auto operator=(const virtual_immovable&) -> virtual_immovable& = delete;
+};
+
+#line 10 "include/beman/execution/detail/unspecified_promise.hpp"
+namespace beman::execution::detail {
+struct unspecified_promise {
+    auto get_return_object() noexcept -> unspecified_promise;
+    auto initial_suspend() noexcept -> ::std::suspend_never;
+    auto final_suspend() noexcept -> ::std::suspend_never;
+    void unhandled_exception() noexcept;
+    void return_void() noexcept;
+    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<>;
+};
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/await_suspend_result.hpp"
+namespace beman::execution::detail {
+
+#line 20 "include/beman/execution/detail/await_suspend_result.hpp"
+template <typename>
+struct is_coroutine_handle : ::std::false_type {};
+
+#line 27 "include/beman/execution/detail/await_suspend_result.hpp"
+template <typename T>
+struct is_coroutine_handle<::std::coroutine_handle<T>> : ::std::true_type {};
+
+#line 35 "include/beman/execution/detail/await_suspend_result.hpp"
+template <typename T>
+concept await_suspend_result =
+    ::std::same_as<T, void> || ::std::same_as<T, bool> || ::beman::execution::detail::is_coroutine_handle<T>::value;
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/valid_specialization.hpp"
+namespace beman::execution::detail {
+template <template <typename...> class T, typename... Args>
+concept valid_specialization = requires { typename T<Args...>; };
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/indirect_meta_apply.hpp"
+namespace beman::execution::detail {
+template <bool>
+struct indirect_meta_apply {
+    template <template <typename...> class T, class... A>
+    using meta_apply = T<A...>;
+};
+} // namespace beman::execution::detail
+
+#line 12 "include/beman/execution/detail/indices_for.hpp"
+namespace beman::execution::detail {
+
+export /* --------- */ template <typename Sender>
+using indices_for = typename ::std::remove_reference_t<Sender>::indices_for;
+} // namespace beman::execution::detail
+
+#line 12 "include/beman/execution/detail/decayed_typeof.hpp"
+namespace beman::execution::detail {
+
+#line 18 "include/beman/execution/detail/decayed_typeof.hpp"
+template <auto&& Tag>
+using decayed_typeof = ::std::decay_t<decltype(Tag)>;
+} // namespace beman::execution::detail
+
+#line 11 "include/beman/execution/detail/nostopstate.hpp"
+namespace beman::execution {
+export /* --------- */ struct nostopstate_t {
+    explicit nostopstate_t() = default;
+};
+
+export /* --------- */ inline constexpr nostopstate_t nostopstate{};
+} // namespace beman::execution
+
+#line 14 "include/beman/execution/detail/env.hpp"
+namespace beman::execution::detail {
+template <::beman::execution::detail::queryable Env>
+struct env_base {
+    Env env_;
+};
+
+template <typename E, typename Q>
+concept has_query = requires(const E& e) { e.query(::std::declval<Q>()); };
+
+template <typename Q, typename... E>
+struct find_env;
+template <typename Q, typename E0, typename... E>
+    requires has_query<E0, Q>
+struct find_env<Q, E0, E...> {
+    using type = E0;
+};
+template <typename Q, typename E0, typename... E>
+    requires(not has_query<E0, Q>)
+struct find_env<Q, E0, E...> {
+    using type = typename find_env<Q, E...>::type;
+};
+} // namespace beman::execution::detail
+
+#line 39 "include/beman/execution/detail/env.hpp"
+namespace beman::execution {
+export /* --------- */ template <::beman::execution::detail::queryable... Envs>
+struct env : ::beman::execution::detail::env_base<Envs>... {
+    [[no_unique_address]] ::beman::execution::detail::non_assignable na_{};
+
+    template <typename Q>
+        requires(::beman::execution::detail::has_query<Envs, Q> || ...)
+    constexpr auto query(Q q) const noexcept -> decltype(auto) {
+        using E = typename ::beman::execution::detail::find_env<Q, Envs...>::type;
+        return q(static_cast<const ::beman::execution::detail::env_base<E>&>(*this).env_);
+    }
+};
+
+template <::beman::execution::detail::queryable... Envs>
+env(Envs...) -> env<::std::unwrap_reference_t<Envs>...>;
+} // namespace beman::execution
+
+#line 17 "include/beman/execution/detail/get_allocator.hpp"
+namespace beman::execution {
+export /* --------- */ struct get_allocator_t {
+    template <typename Object>
+        requires(not requires(Object&& object, const get_allocator_t& tag) { ::std::as_const(object).query(tag); })
+    auto
+    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the object requires a const query(get_allocator_t) overload");
+    template <typename Object>
+        requires(
+                    not requires(const Object& object, const get_allocator_t& tag) { object.query(tag); } &&
+                    not requires(Object&& object, const get_allocator_t& tag) { ::std::as_const(object).query(tag); })
+    auto operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the object requires a query(get_allocator_t) overload");
+    template <typename Object>
+        requires(not requires(const Object& object, const get_allocator_t& tag) {
+                    { object.query(tag) } noexcept;
+                })
+    auto
+    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the query(get_allocator_t) overload needs to be noexcept");
+
+    template <typename Object>
+        requires(not requires(const Object& object, const get_allocator_t& tag) {
+                    { object.query(tag) } noexcept -> ::beman::execution::detail::simple_allocator<>;
+                })
+    auto
+    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the query(get_allocator_t) overload needs to be noexcept");
+
+    template <typename Object>
+        requires(requires(const Object& object, const get_allocator_t& tag) {
+            { object.query(tag) } noexcept -> ::beman::execution::detail::simple_allocator<>;
+        })
+    auto operator()(Object&& object) const noexcept {
+        return ::std::as_const(object).query(*this);
+    }
+#line 50 "include/beman/execution/detail/get_allocator.hpp"
+    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
+};
+
+export /* --------- */ inline constexpr get_allocator_t get_allocator{};
+} // namespace beman::execution
+
+#line 15 "include/beman/execution/detail/get_domain.hpp"
+namespace beman::execution {
+export /* --------- */ struct get_domain_t {
+    template <typename Object>
+        requires(not requires(Object&& object, const get_domain_t& tag) {
+                    ::std::forward<Object>(object).query(tag);
+                }) && (not requires(Object&& object, const get_domain_t& tag) { ::std::as_const(object).query(tag); })
+    auto operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("object needs a query(get_domain_t) overload");
+    template <typename Object>
+        requires(not requires(Object&& object, const get_domain_t& tag) { ::std::as_const(object).query(tag); })
+    auto
+    operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("query(get_domain_t) overload needs to be const");
+    template <typename Object>
+        requires(not requires(Object&& object, const get_domain_t& tag) {
+                    { ::std::as_const(object).query(tag) } noexcept;
+                })
+    auto
+    operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("query(get_domain_t) overload needs to be noexcept");
+
+    template <typename Object>
+    constexpr auto operator()(Object&& object) const noexcept {
+        return ::std::as_const(object).query(*this);
+    }
+    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
+};
+
+export /* --------- */ inline constexpr get_domain_t get_domain{};
+} // namespace beman::execution
+
+#line 13 "include/beman/execution/detail/get_scheduler.hpp"
+namespace beman::execution {
+export /* --------- */ struct get_scheduler_t : ::beman::execution::forwarding_query_t {
+    template <typename Env>
+        requires requires(const get_scheduler_t& self, Env&& env) { ::std::as_const(env).query(self); }
+    auto operator()(Env&& env) const noexcept {
+        static_assert(noexcept(::std::as_const(env).query(*this)));
+
+#line 23 "include/beman/execution/detail/get_scheduler.hpp"
+        return ::std::as_const(env).query(*this);
+    }
+};
+
+export /* --------- */ inline constexpr get_scheduler_t get_scheduler{};
+} // namespace beman::execution
+
+#line 14 "include/beman/execution/detail/operation_state.hpp"
+namespace beman::execution {
+export /* --------- */ struct operation_state_t {};
+
+export /* --------- */ template <typename State>
+concept operation_state =
+    ::std::derived_from<typename State::operation_state_concept, ::beman::execution::operation_state_t> &&
+    ::std::is_object_v<State> && requires(State& state) {
+        { ::beman::execution::start(state) } noexcept;
+    };
+} // namespace beman::execution
+
+#line 16 "include/beman/execution/detail/valid_completion_for.hpp"
+namespace beman::execution::detail {
+template <typename, typename>
+struct valid_completion_for_aux;
+
+template <typename Rcvr, typename Tag, typename... Args>
+struct valid_completion_for_aux<Rcvr, Tag (*)(Args...)> {
+    static auto test(Tag (*)(Args...)) -> void
+        requires ::beman::execution::detail::callable<Tag, ::std::remove_cvref_t<Rcvr>, Args...>
+    {}
+};
+
+export /* --------- */ template <typename Signature, typename Rcvr>
+concept valid_completion_for = requires(Signature* signature) {
+#if 1
+    valid_completion_for_aux<Rcvr, Signature*>::test(signature);
+#else
+#line 33 "include/beman/execution/detail/valid_completion_for.hpp"
+    []<typename Tag, typename... Args>(Tag (*)(Args...))
+        requires ::beman::execution::detail::callable<Tag, ::std::remove_cvref_t<Rcvr>, Args...>
+    {}(signature);
 #endif
+};
+} // namespace beman::execution::detail
+
+#line 15 "include/beman/execution/detail/completion_signature.hpp"
+namespace beman::execution::detail {
+template <typename>
+struct is_set_error : ::std::false_type {};
+template <typename Error>
+struct is_set_error<::beman::execution::set_error_t(Error)> : ::std::true_type {};
+
+template <typename Fun>
+using is_set_stopped = ::std::is_same<Fun, ::beman::execution::set_stopped_t()>;
+
+template <typename>
+struct is_set_value : ::std::false_type {};
+template <typename... Args>
+struct is_set_value<::beman::execution::set_value_t(Args...)> : ::std::true_type {};
+
+#line 42 "include/beman/execution/detail/completion_signature.hpp"
+template <typename Fun>
+concept completion_signature =
+    ::beman::execution::detail::is_set_error<Fun>::value || ::beman::execution::detail::is_set_stopped<Fun>::value ||
+    ::beman::execution::detail::is_set_value<Fun>::value;
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/prop.hpp"
+namespace beman::execution::detail {
+template <typename>
+struct prop_like;
+}
+#line 19 "include/beman/execution/detail/prop.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Query, typename Value>
+struct prop;
+
+template <typename Query, typename Value>
+prop(Query, Value, ::beman::execution::detail::non_assignable = {}) -> prop<Query, ::std::unwrap_reference_t<Value>>;
+} // namespace beman::execution
+
+template <typename V>
+struct beman::execution::detail::prop_like {
+    V    value;
+    auto query(auto) const noexcept -> const V& { return this->value; }
+};
+
+template <typename Query, typename Value>
+struct beman::execution::prop {
+    static_assert(::beman::execution::detail::callable<Query, ::beman::execution::detail::prop_like<Value>>);
+
+    [[no_unique_address]] Query                                      query_{};
+    [[no_unique_address]] Value                                      value_{};
+    [[no_unique_address]] ::beman::execution::detail::non_assignable non_assignable_{};
+
+#line 46 "include/beman/execution/detail/prop.hpp"
+    constexpr auto query(Query) const noexcept -> const Value& { return this->value_; }
+};
+
+#line 13 "include/beman/execution/detail/stoppable_token.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Token>
+concept stoppable_token = requires(const Token& token) {
+    typename ::beman::execution::detail::check_type_alias_exist<Token::template callback_type>;
+    { token.stop_requested() } noexcept -> ::std::same_as<bool>;
+    { token.stop_possible() } noexcept -> ::std::same_as<bool>;
+    { Token(token) } noexcept;
+} && ::std::copyable<Token> && ::std::equality_comparable<Token> && ::std::swappable<Token>;
+} // namespace beman::execution
+
+#line 15 "include/beman/execution/detail/completion_tag.hpp"
+namespace beman::execution::detail {
+
+#line 21 "include/beman/execution/detail/completion_tag.hpp"
+template <typename Tag>
+concept completion_tag =
+    ::std::same_as<Tag, ::beman::execution::set_error_t> || ::std::same_as<Tag, ::beman::execution::set_stopped_t> ||
+    ::std::same_as<Tag, ::beman::execution::set_value_t>;
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/await_result_type.hpp"
+namespace beman::execution::detail {
+
+#line 19 "include/beman/execution/detail/await_result_type.hpp"
+export /* --------- */ template <typename T, typename Promise>
+using await_result_type =
+    decltype(::beman::execution::detail::get_awaiter(::std::declval<T>(), ::std::declval<Promise&>()).await_resume());
+} // namespace beman::execution::detail
+
+#line 16 "include/beman/execution/detail/fwd_env.hpp"
+namespace beman::execution::detail {
+
+#line 22 "include/beman/execution/detail/fwd_env.hpp"
+export /* --------- */ template <typename Env>
+class fwd_env {
+  private:
+    Env env;
+
+  public:
+    explicit fwd_env(Env&& e) : env(::std::forward<Env>(e)) {}
+
+    template <typename Query, typename... Args>
+        requires(!::beman::execution::forwarding_query(::std::remove_cvref_t<Query>()))
+    constexpr auto query(Query&& q,
+                         Args&&... args) const = BEMAN_EXECUTION_DELETE("the used query is not forwardable");
+
+    template <typename Query, typename... Args>
+        requires(::beman::execution::forwarding_query(::std::remove_cvref_t<Query>())) &&
+                requires(const Env& e, Query&& q, Args&&... args) { e.query(q, ::std::forward<Args>(args)...); }
+    constexpr auto query(Query&& q, Args&&... args) const
+        noexcept(noexcept(env.query(q, ::std::forward<Args>(args)...))) {
+        return env.query(q, ::std::forward<Args>(args)...);
+    }
+};
+template <typename Env>
+fwd_env(Env&&) -> fwd_env<Env>;
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/tag_of_t.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Sender>
+using tag_of_t = typename decltype(::beman::execution::detail::get_sender_meta(::std::declval<Sender&&>()))::tag_type;
+}
+#line 13 "include/beman/execution/detail/meta_combine.hpp"
+namespace beman::execution::detail::meta::detail {
+template <typename...>
+struct combine;
+
+template <template <typename...> class L0, typename... T0>
+struct combine<L0<T0...>> {
+    using type = L0<T0...>;
+};
+template <template <typename...> class L0,
+          typename... T0,
+          template <typename...> class L1,
+          typename... T1,
+          typename... L>
+struct combine<L0<T0...>, L1<T1...>, L...> {
+    using type = typename combine<L0<T0..., T1...>, L...>::type;
+};
+} // namespace beman::execution::detail::meta::detail
+
+namespace beman::execution::detail::meta {
+template <typename... L>
+using combine = typename ::beman::execution::detail::meta::detail::combine<L...>::type;
+}
+#line 15 "include/beman/execution/detail/meta_unique.hpp"
+namespace beman::execution::detail::meta::detail {
+template <typename, typename>
+struct make_unique;
+template <typename>
+struct unique;
+
+template <template <typename...> class List, typename... R>
+struct make_unique<List<R...>, List<>> {
+    using type = List<R...>;
+};
+
+template <template <typename...> class List, typename... R, typename H, typename... T>
+struct make_unique<List<R...>, List<H, T...>> {
+    using type = typename ::beman::execution::detail::meta::detail::make_unique<
+        ::std::conditional_t<::beman::execution::detail::meta::contains<H, R...>, List<R...>, List<R..., H>>,
+        List<T...>>::type;
+};
+
+template <template <typename...> class List, typename... T>
+struct unique<List<T...>> {
+    using type = typename ::beman::execution::detail::meta::detail::make_unique<List<>, List<T...>>::type;
+};
+} // namespace beman::execution::detail::meta::detail
+
+namespace beman::execution::detail::meta {
+template <typename T>
+using unique = typename ::beman::execution::detail::meta::detail::unique<T>::type;
+}
+#line 13 "include/beman/execution/detail/meta_filter.hpp"
+namespace beman::execution::detail::meta::detail {
+template <template <typename> class, typename>
+struct filter;
+
+template <template <typename, typename> class, typename, typename>
+struct filter_tag;
+
+template <template <typename> class Predicate, template <typename...> class List>
+struct filter<Predicate, List<>> {
+    using type = List<>;
+};
+
+template <template <typename, typename> class Predicate, typename Tag, template <typename...> class List>
+struct filter_tag<Predicate, Tag, List<>> {
+    using type = List<>;
+};
+
+template <template <typename> class Predicate, template <typename...> class List, typename H, typename... T>
+struct filter<Predicate, List<H, T...>> {
+    using tail = typename beman::execution::detail::meta::detail::filter<Predicate, List<T...>>::type;
+    using type = ::std::conditional_t<Predicate<H>::value, ::beman::execution::detail::meta::prepend<H, tail>, tail>;
+};
+
+template <template <typename, typename> class Predicate,
+          typename Tag,
+          template <typename...> class List,
+          typename H,
+          typename... T>
+struct filter_tag<Predicate, Tag, List<H, T...>> {
+    using tail = typename beman::execution::detail::meta::detail::filter_tag<Predicate, Tag, List<T...>>::type;
+    using type =
+        ::std::conditional_t<Predicate<Tag, H>::value, ::beman::execution::detail::meta::prepend<H, tail>, tail>;
+};
+} // namespace beman::execution::detail::meta::detail
+
+namespace beman::execution::detail::meta {
+template <template <typename> class Predicate, typename List>
+using filter = typename ::beman::execution::detail::meta::detail::filter<Predicate, List>::type;
+
+template <template <typename, typename> class Predicate, typename Tag, typename List>
+using filter_tag = typename ::beman::execution::detail::meta::detail::filter_tag<Predicate, Tag, List>::type;
+} // namespace beman::execution::detail::meta
+
+#line 12 "include/beman/execution/detail/meta_transform.hpp"
+namespace beman::execution::detail::meta::detail {
+template <template <typename> class Transform, typename List>
+struct transform;
+
+template <template <typename> class Transform, template <typename... T> class List, typename... T>
+struct transform<Transform, List<T...>> {
+    using type = List<Transform<T>...>;
+};
+} // namespace beman::execution::detail::meta::detail
+
+namespace beman::execution::detail::meta {
+template <template <typename> class Transform, typename List>
+using transform = typename ::beman::execution::detail::meta::detail::transform<Transform, List>::type;
+}
+#line 12 "include/beman/execution/detail/as_tuple.hpp"
+namespace beman::execution::detail {
+
+#line 17 "include/beman/execution/detail/as_tuple.hpp"
+template <typename T>
+struct as_tuple;
+
+#line 23 "include/beman/execution/detail/as_tuple.hpp"
+template <typename Rc, typename... A>
+struct as_tuple<Rc(A...)> {
+    using type = ::beman::execution::detail::decayed_tuple<Rc, A...>;
+};
+
+template <typename T>
+using as_tuple_t = typename ::beman::execution::detail::as_tuple<T>::type;
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
+namespace beman::execution::detail {
+
+template <auto Next>
+class atomic_intrusive_stack;
+
+#line 35 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
+template <class Item, Item* Item::* Next>
+class atomic_intrusive_stack<Next> {
+  public:
+    atomic_intrusive_stack() = default;
+    ~atomic_intrusive_stack() { assert(!head_ || head_ == this); }
+    atomic_intrusive_stack(const atomic_intrusive_stack&)                        = delete;
+    auto operator=(const atomic_intrusive_stack&) -> atomic_intrusive_stack&     = delete;
+    atomic_intrusive_stack(atomic_intrusive_stack&&) noexcept                    = delete;
+    auto operator=(atomic_intrusive_stack&&) noexcept -> atomic_intrusive_stack& = delete;
+
+#line 51 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
+    auto try_push(Item* item) noexcept -> std::optional<Item*> {
+        void* ptr = head_.load();
+        if (ptr == this) {
+            return std::nullopt;
+        }
+        item->*Next = static_cast<Item*>(ptr);
+        while (!head_.compare_exchange_weak(ptr, item)) {
+            if (ptr == this) {
+                return std::nullopt;
+            }
+            item->*Next = static_cast<Item*>(ptr);
+        }
+        return static_cast<Item*>(ptr);
+    }
+#line 67 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
+    auto empty_and_not_shutdown() const noexcept -> bool { return head_.load() == nullptr; }
+
+#line 72 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
+    auto pop_all_and_shutdown() noexcept -> ::beman::execution::detail::intrusive_stack<Next> {
+        auto  stack = ::beman::execution::detail::intrusive_stack<Next>{};
+        void* ptr   = head_.exchange(this);
+        if (ptr == this) {
+            return stack;
+        }
+        auto item   = static_cast<Item*>(ptr);
+        stack.head_ = item;
+        return stack;
+    }
+#line 83 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
+  private:
+    ::std::atomic<void*> head_{nullptr};
+};
+
+} // namespace beman::execution::detail
+
+#line 17 "include/beman/execution/detail/inplace_stop_source.hpp"
+namespace beman::execution {
+export /* --------- */ class inplace_stop_token;
+export /* --------- */ class inplace_stop_source;
+export /* --------- */ template <typename CallbackFun>
+class inplace_stop_callback;
+export /* --------- */ template <typename CallbackFun>
+inplace_stop_callback(::beman::execution::inplace_stop_token, CallbackFun) -> inplace_stop_callback<CallbackFun>;
+} // namespace beman::execution
+
+#line 28 "include/beman/execution/detail/inplace_stop_source.hpp"
+class beman::execution::inplace_stop_token {
+  public:
+    template <typename CallbackFun>
+    using callback_type = ::beman::execution::inplace_stop_callback<CallbackFun>;
+
+    inplace_stop_token() = default;
+
+    constexpr auto stop_requested() const noexcept -> bool;
+    constexpr auto stop_possible() const noexcept -> bool;
+    auto           operator==(const inplace_stop_token&) const -> bool = default;
+
+    auto swap(inplace_stop_token&) noexcept -> void;
+
+  private:
+    friend class ::beman::execution::inplace_stop_source;
+    template <typename CallbackFun>
+    friend class ::beman::execution::inplace_stop_callback;
+    explicit inplace_stop_token(::beman::execution::inplace_stop_source* src) : source(src) {}
+
+    ::beman::execution::inplace_stop_source* source{};
+};
+
+#line 52 "include/beman/execution/detail/inplace_stop_source.hpp"
+class beman::execution::inplace_stop_source {
+    struct callback_base : public ::beman::execution::detail::virtual_immovable {
+        callback_base* next{};
+        virtual auto   call() -> void = 0;
+    };
+
+  public:
+    auto                  stop_requested() const noexcept -> bool;
+    static constexpr auto stop_possible() noexcept -> bool;
+    auto                  get_token() const -> ::beman::execution::inplace_stop_token;
+
+    auto request_stop() -> bool;
+
+  private:
+    template <typename CallbackFun>
+    friend class ::beman::execution::inplace_stop_callback;
+    ::std::atomic<bool>           stopped{};
+    ::std::atomic<callback_base*> running{};
+    ::std::thread::id             id{};
+    ::std::mutex                  lock;
+    callback_base*                callbacks{};
+
+    auto add(callback_base* cb) -> void;
+    auto deregister(callback_base* cb) -> void;
+};
+
+#line 80 "include/beman/execution/detail/inplace_stop_source.hpp"
+template <typename CallbackFun>
+class beman::execution::inplace_stop_callback final : public ::beman::execution::inplace_stop_source::callback_base {
+  public:
+    using callback_type = CallbackFun;
+
+    template <typename Init>
+    inplace_stop_callback(::beman::execution::inplace_stop_token, Init&&);
+    inplace_stop_callback(const inplace_stop_callback&) = delete;
+    inplace_stop_callback(inplace_stop_callback&&)      = delete;
+    ~inplace_stop_callback() override {
+        if (this->source) {
+            this->source->deregister(this);
+        }
+    }
+    auto operator=(const inplace_stop_callback&) -> inplace_stop_callback& = delete;
+    auto operator=(inplace_stop_callback&&) -> inplace_stop_callback&      = delete;
+
+  private:
+    auto call() -> void override;
+
+    CallbackFun                              fun;
+    ::beman::execution::inplace_stop_source* source;
+};
+
+#line 106 "include/beman/execution/detail/inplace_stop_source.hpp"
+inline constexpr auto beman::execution::inplace_stop_token::stop_requested() const noexcept -> bool {
+    return this->source && this->source->stop_requested();
+}
+#line 110 "include/beman/execution/detail/inplace_stop_source.hpp"
+inline constexpr auto beman::execution::inplace_stop_token::stop_possible() const noexcept -> bool {
+    return this->source;
+}
+#line 114 "include/beman/execution/detail/inplace_stop_source.hpp"
+inline auto beman::execution::inplace_stop_token::swap(inplace_stop_token& other) noexcept -> void {
+    ::std::swap(this->source, other.source);
+}
+#line 118 "include/beman/execution/detail/inplace_stop_source.hpp"
+inline auto beman::execution::inplace_stop_source::stop_requested() const noexcept -> bool { return this->stopped; }
+
+inline constexpr auto beman::execution::inplace_stop_source::stop_possible() noexcept -> bool { return true; }
+
+inline auto beman::execution::inplace_stop_source::get_token() const -> ::beman::execution::inplace_stop_token {
+    return ::beman::execution::inplace_stop_token(const_cast<::beman::execution::inplace_stop_source*>(this));
+}
+#line 126 "include/beman/execution/detail/inplace_stop_source.hpp"
+inline auto beman::execution::inplace_stop_source::request_stop() -> bool {
+    using relock = ::std::unique_ptr<::std::unique_lock<::std::mutex>, decltype([](auto p) { p->lock(); })>;
+    if (false == this->stopped.exchange(true)) {
+        ::std::unique_lock guard(this->lock);
+        for (auto it = this->callbacks; it != nullptr; it = this->callbacks) {
+            this->running   = it;
+            this->id        = ::std::this_thread::get_id();
+            this->callbacks = it->next;
+            {
+                relock r(&guard);
+                guard.unlock();
+                it->call();
+            }
+            this->running = nullptr;
+        }
+        return true;
+    }
+    return false;
+}
+#line 146 "include/beman/execution/detail/inplace_stop_source.hpp"
+inline auto beman::execution::inplace_stop_source::add(callback_base* cb) -> void {
+    if (this->stopped) {
+        cb->call();
+    } else {
+        ::std::lock_guard guard(this->lock);
+        cb->next = ::std::exchange(this->callbacks, cb);
+    }
+}
+#line 155 "include/beman/execution/detail/inplace_stop_source.hpp"
+inline auto beman::execution::inplace_stop_source::deregister(callback_base* cb) -> void {
+    ::std::unique_lock guard(this->lock);
+    if (this->running == cb) {
+        if (this->id == ::std::this_thread::get_id()) {
+            return;
+        }
+        guard.unlock();
+        while (this->running == cb) {
+        }
+        return;
+    }
+#line 167 "include/beman/execution/detail/inplace_stop_source.hpp"
+    for (callback_base** it{&this->callbacks}; *it; it = &(*it)->next) {
+        if (*it == cb) {
+            *it = cb->next;
+            break;
+        }
+    }
+}
+#line 175 "include/beman/execution/detail/inplace_stop_source.hpp"
+template <typename CallbackFun>
+template <typename Init>
+inline beman::execution::inplace_stop_callback<CallbackFun>::inplace_stop_callback(
+    ::beman::execution::inplace_stop_token token, Init&& init)
+    : fun(::std::forward<Init>(init)), source(token.source) {
+    if (this->source) {
+        this->source->add(this);
+    }
+}
+#line 185 "include/beman/execution/detail/inplace_stop_source.hpp"
+template <typename CallbackFun>
+inline auto beman::execution::inplace_stop_callback<CallbackFun>::call() -> void {
+    this->fun();
+}
+#line 13 "include/beman/execution/detail/decayed_type_list.hpp"
+namespace beman::execution::detail {
+template <class... Args>
+using decayed_type_list = ::beman::execution::detail::type_list<::std::decay_t<Args>...>;
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/class_type.hpp"
+namespace beman::execution::detail {
+
+#line 19 "include/beman/execution/detail/class_type.hpp"
+template <typename Tp>
+concept class_type = ::beman::execution::detail::decays_to<Tp, Tp> && ::std::is_class_v<Tp>;
+} // namespace beman::execution::detail
+
+#line 12 "include/beman/execution/detail/nothrow_callable.hpp"
+namespace beman::execution::detail {
+template <typename Fun, typename... Args>
+concept nothrow_callable = ::beman::execution::detail::callable<Fun, Args...> && requires(Fun&& fun, Args&&... args) {
+    { ::std::forward<Fun>(fun)(::std::forward<Args>(args)...) } noexcept;
+};
+} // namespace beman::execution::detail
+
+#line 16 "include/beman/execution/detail/counting_scope_base.hpp"
+namespace beman::execution::detail {
+class counting_scope_base;
+}
+#line 22 "include/beman/execution/detail/counting_scope_base.hpp"
+class beman::execution::detail::counting_scope_base : ::beman::execution::detail::immovable {
+  public:
+    counting_scope_base()                      = default;
+    counting_scope_base(counting_scope_base&&) = delete;
+    ~counting_scope_base();
+
+    static constexpr ::std::size_t max_associations{8194u};
+
+    auto close() noexcept -> void;
+
+    struct node {
+        virtual auto complete() noexcept -> void        = 0;
+        virtual auto complete_inline() noexcept -> void = 0;
+        node*        next{};
+    };
+    auto start_node(node*) -> void;
+
+  protected:
+    class token {
+      public:
+        auto try_associate() const noexcept -> bool { return this->scope->try_associate(); }
+        auto disassociate() const noexcept -> void { this->scope->disassociate(); }
+
+      protected:
+        explicit token(::beman::execution::detail::counting_scope_base* s) : scope(s) {}
+        ::beman::execution::detail::counting_scope_base* scope;
+    };
+
+  private:
+    enum class state_t : unsigned char {
+        unused,
+        open,
+        open_and_joining,
+        closed,
+        closed_and_joining,
+        unused_and_closed,
+        joined
+    };
+
+    auto try_associate() noexcept -> bool;
+    auto disassociate() noexcept -> void;
+    auto complete() noexcept -> void;
+    auto add_node(node* n, ::std::lock_guard<::std::mutex>&) noexcept -> void;
+
+    ::std::mutex mutex;
+
+    ::std::size_t count{};
+    state_t       state{state_t::unused};
+    node*         head{};
+};
+
+#line 75 "include/beman/execution/detail/counting_scope_base.hpp"
+inline beman::execution::detail::counting_scope_base::~counting_scope_base() {
+    ::std::lock_guard kerberos(this->mutex);
+    switch (this->state) {
+    default:
+        ::std::terminate();
+    case state_t::unused:
+    case state_t::unused_and_closed:
+    case state_t::joined:
+        break;
+    }
+}
+#line 87 "include/beman/execution/detail/counting_scope_base.hpp"
+inline auto beman::execution::detail::counting_scope_base::close() noexcept -> void {
+    switch (this->state) {
+    default:
+        break;
+    case state_t::unused:
+        this->state = state_t::unused_and_closed;
+        break;
+    case state_t::open:
+        this->state = state_t::closed;
+        break;
+    case state_t::open_and_joining:
+        this->state = state_t::closed_and_joining;
+        break;
+    }
+}
+#line 103 "include/beman/execution/detail/counting_scope_base.hpp"
+inline auto beman::execution::detail::counting_scope_base::add_node(node* n, ::std::lock_guard<::std::mutex>&) noexcept
+    -> void {
+    n->next = std::exchange(this->head, n);
+}
+#line 108 "include/beman/execution/detail/counting_scope_base.hpp"
+inline auto beman::execution::detail::counting_scope_base::try_associate() noexcept -> bool {
+    ::std::lock_guard lock(this->mutex);
+    switch (this->state) {
+    default:
+        return false;
+    case state_t::unused:
+        this->state = state_t::open;
+        [[fallthrough]];
+    case state_t::open:
+    case state_t::open_and_joining:
+        ++this->count;
+        return true;
+    }
+}
+#line 123 "include/beman/execution/detail/counting_scope_base.hpp"
+inline auto beman::execution::detail::counting_scope_base::disassociate() noexcept -> void {
+    {
+        ::std::lock_guard lock(this->mutex);
+        if (0u < --this->count)
+            return;
+        this->state = state_t::joined;
+    }
+    this->complete();
+}
+#line 133 "include/beman/execution/detail/counting_scope_base.hpp"
+inline auto beman::execution::detail::counting_scope_base::complete() noexcept -> void {
+    node* current{[this] {
+        ::std::lock_guard lock(this->mutex);
+        return ::std::exchange(this->head, nullptr);
+    }()};
+    while (current) {
+        ::std::exchange(current, current->next)->complete();
+    }
+}
+#line 143 "include/beman/execution/detail/counting_scope_base.hpp"
+inline auto beman::execution::detail::counting_scope_base::start_node(node* n) -> void {
+    ::std::lock_guard kerberos(this->mutex);
+    switch (this->state) {
+    case ::beman::execution::detail::counting_scope_base::state_t::unused:
+    case ::beman::execution::detail::counting_scope_base::state_t::unused_and_closed:
+    case ::beman::execution::detail::counting_scope_base::state_t::joined:
+        this->state = ::beman::execution::detail::counting_scope_base::state_t::joined;
+        n->complete_inline();
+        return;
+    case ::beman::execution::detail::counting_scope_base::state_t::open:
+        this->state = ::beman::execution::detail::counting_scope_base::state_t::open_and_joining;
+        break;
+    case ::beman::execution::detail::counting_scope_base::state_t::open_and_joining:
+        break;
+    case ::beman::execution::detail::counting_scope_base::state_t::closed:
+        this->state = ::beman::execution::detail::counting_scope_base::state_t::closed_and_joining;
+        break;
+    case ::beman::execution::detail::counting_scope_base::state_t::closed_and_joining:
+        break;
+    }
+    this->add_node(n, kerberos);
+}
+#line 13 "include/beman/execution/detail/is_awaiter.hpp"
+namespace beman::execution::detail {
+template <typename Awaiter, typename Promise>
+concept is_awaiter = requires(Awaiter& awaiter, ::std::coroutine_handle<Promise> handle) {
+    awaiter.await_ready() ? 1 : 0;
+    { awaiter.await_suspend(handle) } -> ::beman::execution::detail::await_suspend_result;
+    awaiter.await_resume();
+};
+} // namespace beman::execution::detail
+
+#line 18 "include/beman/execution/detail/stop_source.hpp"
+namespace beman::execution {
+export /* --------- */ class stop_token;
+export /* --------- */ class stop_source;
+export /* --------- */ template <typename CallbackFun>
+class stop_callback;
+export /* --------- */ template <typename CallbackFun>
+stop_callback(::beman::execution::stop_token, CallbackFun) -> stop_callback<CallbackFun>;
+} // namespace beman::execution
+
+namespace beman::execution::detail {
+struct stop_state;
+struct stop_callback_base;
+} // namespace beman::execution::detail
+
+#line 33 "include/beman/execution/detail/stop_source.hpp"
+struct beman::execution::detail::stop_state {
+    ::std::atomic<bool>                           stop_requested{};
+    ::std::atomic<::std::size_t>                  sources{};
+    ::std::mutex                                  lock{};
+    beman::execution::detail::stop_callback_base* callbacks{};
+    ::std::atomic<bool>                           executing{};
+
+    auto stop_possible() const -> bool { return this->sources != 0 || this->stop_requested; }
+};
+
+#line 45 "include/beman/execution/detail/stop_source.hpp"
+struct beman::execution::detail::stop_callback_base {
+  private:
+    using stop_state = ::beman::execution::detail::stop_state;
+    ::std::shared_ptr<stop_state> state;
+
+    virtual auto do_call() -> void = 0;
+
+  protected:
+    explicit stop_callback_base(const ::beman::execution::stop_token&);
+    ~stop_callback_base();
+
+  public:
+    stop_callback_base(stop_callback_base&&)                         = delete;
+    stop_callback_base(const stop_callback_base&)                    = delete;
+    auto operator=(stop_callback_base&&) -> stop_callback_base&      = delete;
+    auto operator=(const stop_callback_base&) -> stop_callback_base& = delete;
+    auto call() -> void;
+    auto setup() -> void;
+    auto deregister() -> void;
+
+    stop_callback_base* next{};
+    ::std::thread::id   id{};
+};
+
+#line 71 "include/beman/execution/detail/stop_source.hpp"
+class beman::execution::stop_source {
+  private:
+    using stop_state = ::beman::execution::detail::stop_state;
+
+    ::std::shared_ptr<stop_state> state{::std::make_shared<stop_state>()};
+
+  public:
+    using stop_token = ::beman::execution::stop_token;
+
+    stop_source();
+    explicit stop_source(::beman::execution::nostopstate_t) noexcept;
+    stop_source(const stop_source&);
+    stop_source(stop_source&&) = default;
+    auto operator=(const stop_source&) -> stop_source&;
+    auto operator=(stop_source&&) -> stop_source& = default;
+    ~stop_source();
+
+    auto swap(stop_source&) noexcept -> void;
+    auto get_token() const -> stop_token;
+    auto stop_requested() const noexcept -> bool;
+    auto stop_possible() const noexcept -> bool;
+    auto request_stop() noexcept -> bool;
+};
+
+#line 97 "include/beman/execution/detail/stop_source.hpp"
+class beman::execution::stop_token {
+  private:
+    friend ::beman::execution::stop_source;
+    friend ::beman::execution::detail::stop_callback_base;
+    ::std::shared_ptr<::beman::execution::detail::stop_state> state;
+
+    explicit stop_token(::std::shared_ptr<::beman::execution::detail::stop_state>);
+
+  public:
+    template <typename Fun>
+    using callback_type = ::beman::execution::stop_callback<Fun>;
+
+    stop_token() = default;
+
+    auto               swap(stop_token& other) noexcept -> void;
+    [[nodiscard]] auto stop_requested() const noexcept -> bool;
+    [[nodiscard]] auto stop_possible() const noexcept -> bool;
+
+    [[nodiscard]] auto operator==(const stop_token&) const noexcept -> bool = default;
+};
+
+#line 120 "include/beman/execution/detail/stop_source.hpp"
+template <typename CallbackFun>
+class beman::execution::stop_callback final : private CallbackFun, beman::execution::detail::stop_callback_base {
+  private:
+    static_assert(::std::invocable<CallbackFun>);
+    static_assert(::std::destructible<CallbackFun>);
+
+    using stop_token = ::beman::execution::stop_token;
+
+    auto do_call() -> void override { (*this)(); }
+
+  public:
+    using callback_type = CallbackFun;
+
+    template <typename Initializer>
+    stop_callback(const stop_token& token,
+                  Initializer&&     init) noexcept(::std::is_nothrow_constructible_v<CallbackFun, Initializer>)
+        requires(::std::constructible_from<CallbackFun, Initializer>)
+        : CallbackFun(::std::forward<Initializer>(init)), stop_callback_base(token) {
+        this->setup();
+    }
+    template <typename Initializer>
+    stop_callback(stop_token&&  token,
+                  Initializer&& init) noexcept(::std::is_nothrow_constructible_v<CallbackFun, Initializer>)
+        requires(::std::is_constructible_v<CallbackFun, Initializer>)
+        : CallbackFun(::std::forward<Initializer>(init)), stop_callback_base(::std::move(token)) {
+        this->setup();
+    }
+    stop_callback(const stop_callback&) = delete;
+    stop_callback(stop_callback&&)      = delete;
+    ~stop_callback() { this->deregister(); }
+    auto operator=(stop_callback&&) -> stop_callback&      = delete;
+    auto operator=(const stop_callback&) -> stop_callback& = delete;
+};
+
+#line 156 "include/beman/execution/detail/stop_source.hpp"
+inline beman::execution::detail::stop_callback_base::stop_callback_base(const ::beman::execution::stop_token& token)
+    : state(token.state) {}
+
+inline beman::execution::detail::stop_callback_base::~stop_callback_base() {}
+
+inline auto beman::execution::detail::stop_callback_base::setup() -> void {
+    if (this->state) {
+        {
+            ::std::lock_guard guard(this->state->lock);
+            if (!this->state->stop_requested) {
+                this->next = ::std::exchange(this->state->callbacks, this);
+                return;
+            }
+        }
+        this->call();
+    }
+}
+#line 174 "include/beman/execution/detail/stop_source.hpp"
+inline auto beman::execution::detail::stop_callback_base::deregister() -> void {
+    if (this->state) {
+        ::std::unique_lock guard(this->state->lock);
+        if (this->state->executing && this->id != ::std::this_thread::get_id()) {
+            using lock_again = decltype([](auto p) { p->lock(); });
+            ::std::unique_ptr<decltype(guard), lock_again> relock(&guard);
+            relock->unlock();
+            while (this->state->executing)
+                ;
+        }
+        for (auto n = &this->state->callbacks; *n; n = &this->next) {
+            if (*n == this) {
+                *n = this->next;
+                break;
+            }
+        }
+    }
+}
+#line 193 "include/beman/execution/detail/stop_source.hpp"
+inline auto beman::execution::detail::stop_callback_base::call() -> void { this->do_call(); }
+
+inline beman::execution::stop_token::stop_token(::std::shared_ptr<::beman::execution::detail::stop_state> st)
+    : state(::std::move(st)) {}
+
+inline auto beman::execution::stop_token::swap(stop_token& other) noexcept -> void { this->state.swap(other.state); }
+
+inline auto beman::execution::stop_token::stop_requested() const noexcept -> bool {
+    return this->state && this->state->stop_requested;
+}
+#line 204 "include/beman/execution/detail/stop_source.hpp"
+inline auto beman::execution::stop_token::stop_possible() const noexcept -> bool {
+    return this->state && this->state->stop_possible();
+}
+#line 210 "include/beman/execution/detail/stop_source.hpp"
+inline beman::execution::stop_source::stop_source() { ++this->state->sources; }
+
+inline beman::execution::stop_source::stop_source(::beman::execution::nostopstate_t) noexcept : state() {}
+
+inline beman::execution::stop_source::stop_source(const stop_source& other) : state(other.state) {
+    ++this->state->sources;
+}
+#line 218 "include/beman/execution/detail/stop_source.hpp"
+inline auto beman::execution::stop_source::operator=(const stop_source& other) -> stop_source& {
+    stop_source(other).swap(*this);
+    return *this;
+}
+#line 223 "include/beman/execution/detail/stop_source.hpp"
+inline beman::execution::stop_source::~stop_source() { this->state && --this->state->sources; }
+
+inline auto beman::execution::stop_source::swap(::beman::execution::stop_source& other) noexcept -> void {
+    this->state.swap(other.state);
+}
+#line 229 "include/beman/execution/detail/stop_source.hpp"
+inline auto beman::execution::stop_source::get_token() const -> stop_token { return stop_token{this->state}; }
+
+inline auto beman::execution::stop_source::stop_requested() const noexcept -> bool {
+    return this->state && this->state->stop_requested;
+}
+#line 235 "include/beman/execution/detail/stop_source.hpp"
+inline auto beman::execution::stop_source::stop_possible() const noexcept -> bool { return true && this->state; }
+
+inline auto beman::execution::stop_source::request_stop() noexcept -> bool {
+    using release    = decltype([](auto p) { *p = false; });
+    using lock_again = decltype([](auto p) { p->lock(); });
+
+    if (this->state && not this->state->stop_requested.exchange(true)) {
+        ::std::unique_lock guard(this->state->lock);
+        while (this->state->callbacks) {
+            auto front = ::std::exchange(this->state->callbacks, this->state->callbacks->next);
+            ::std::unique_ptr<::std::atomic<bool>, release> reset(&state->executing);
+            *reset    = true;
+            front->id = ::std::this_thread::get_id();
+            ::std::unique_ptr<decltype(guard), lock_again> relock(&guard);
+            relock->unlock();
+            front->call();
+        }
+        return true;
+    }
+    return false;
+}
+#line 16 "include/beman/execution/detail/get_stop_token.hpp"
+namespace beman::execution::detail {
+template <typename Token>
+concept decayed_stoppable_token = ::beman::execution::stoppable_token<::std::decay_t<Token>>;
+}
+namespace beman::execution {
+export /* --------- */ struct get_stop_token_t {
+    template <typename Object>
+        requires requires(Object&& object, const get_stop_token_t& tag) {
+            { ::std::as_const(object).query(tag) } noexcept -> ::beman::execution::detail::decayed_stoppable_token;
+        }
+    auto operator()(Object&& object) const noexcept {
+        return ::std::as_const(object).query(*this);
+    }
+#line 30 "include/beman/execution/detail/get_stop_token.hpp"
+    template <typename Object>
+    auto operator()(Object&&) const noexcept -> ::beman::execution::never_stop_token {
+        return {};
+    }
+#line 35 "include/beman/execution/detail/get_stop_token.hpp"
+    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
+};
+
+export /* --------- */ inline constexpr get_stop_token_t get_stop_token{};
+} // namespace beman::execution
+
+#line 15 "include/beman/execution/detail/get_env.hpp"
+namespace beman::execution {
+export /* --------- */ struct get_env_t {
+    template <typename Object>
+        requires(not requires(::std::add_const_t<::std::remove_cvref_t<Object>>& object) { object.get_env(); } ||
+                 ::beman::execution::detail::queryable<
+                     std::remove_cvref_t<decltype(::std::declval<const ::std::remove_cvref_t<Object>&>().get_env())>>)
+    auto operator()(Object&& object) const noexcept -> decltype(auto) {
+        ::std::add_const_t<::std::remove_cvref_t<Object>>& obj{object};
+        if constexpr (requires { obj.get_env(); }) {
+            static_assert(noexcept(obj.get_env()), "get_env requires the expression to be noexcept");
+            static_assert(::beman::execution::detail::queryable<std::remove_cvref_t<decltype(obj.get_env())>>,
+                          "get_env requires the result type to be destructible");
+            return obj.get_env();
+        } else {
+            return ::beman::execution::env<>{};
+        }
+    }
+};
+
+export /* --------- */ inline constexpr get_env_t get_env{};
+} // namespace beman::execution
+
+#line 14 "include/beman/execution/detail/completion_signatures.hpp"
+namespace beman::execution {
+
+#line 24 "include/beman/execution/detail/completion_signatures.hpp"
+export /* --------- */ template <::beman::execution::detail::completion_signature...>
+struct completion_signatures {};
+} // namespace beman::execution
+
+#line 14 "include/beman/execution/detail/is_awaitable.hpp"
+namespace beman::execution::detail {
+template <typename T, typename Promise>
+concept is_awaitable = requires(Promise& promise) {
+    {
+        ::beman::execution::detail::get_awaiter(::std::declval<T>(), promise)
+    } -> ::beman::execution::detail::is_awaiter<Promise>;
+};
+} // namespace beman::execution::detail
+
+#line 15 "include/beman/execution/detail/emplace_from.hpp"
+namespace beman::execution::detail {
+
+#line 21 "include/beman/execution/detail/emplace_from.hpp"
+template <typename Fun>
+struct emplace_from {
+    using type = ::beman::execution::detail::call_result_t<Fun>;
+    Fun fun;
+
+    explicit constexpr operator type() && noexcept(::beman::execution::detail::nothrow_callable<Fun>) {
+        return ::std::move(fun)();
+    }
+};
+template <typename Fun>
+emplace_from(Fun&&) -> emplace_from<::std::remove_cvref_t<Fun>>;
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/variant_or_empty.hpp"
+namespace beman::execution::detail {
+struct empty_variant {
+    empty_variant() = delete;
+};
+
+template <typename... T>
+struct variant_or_empty_helper;
+
+template <>
+struct variant_or_empty_helper<> {
+    using type = ::beman::execution::detail::empty_variant;
+};
+
+template <typename... T>
+struct variant_or_empty_helper {
+    using type = ::beman::execution::detail::meta::unique<::std::variant<::std::decay_t<T>...>>;
+};
+
+template <typename... T>
+using variant_or_empty = typename ::beman::execution::detail::variant_or_empty_helper<T...>::type;
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/stoppable_source.hpp"
+namespace beman::execution::detail {
+export /* --------- */ template <typename Source>
+concept stoppable_source = requires(Source& source, const Source& csource) {
+    { csource.get_token() } -> ::beman::execution::stoppable_token;
+    { csource.stop_possible() } noexcept -> ::std::same_as<bool>;
+    { csource.stop_requested() } noexcept -> ::std::same_as<bool>;
+    { source.request_stop() } -> ::std::same_as<bool>;
+};
+} // namespace beman::execution::detail
+
+#line 15 "include/beman/execution/detail/receiver.hpp"
+namespace beman::execution {
+export /* --------- */ struct receiver_t {};
+
+export /* --------- */ template <typename Rcvr>
+concept receiver =
+    ::std::derived_from<typename ::std::remove_cvref_t<Rcvr>::receiver_concept, ::beman::execution::receiver_t> &&
+    requires(const ::std::remove_cvref_t<Rcvr>& rcvr) {
+        { ::beman::execution::get_env(rcvr) } -> ::beman::execution::detail::queryable;
+    } && ::std::move_constructible<::std::remove_cvref_t<Rcvr>> &&
+    ::std::constructible_from<::std::remove_cvref_t<Rcvr>, Rcvr> && (!::std::is_final_v<::std::remove_cvref_t<Rcvr>>);
+} // namespace beman::execution
+
+#line 13 "include/beman/execution/detail/valid_completion_signatures.hpp"
+namespace beman::execution::detail {
+template <typename>
+struct valid_completion_signatures_helper : ::std::false_type {};
+template <typename... Sigs>
+struct valid_completion_signatures_helper<::beman::execution::completion_signatures<Sigs...>> : ::std::true_type {};
+
+template <typename Signatures>
+concept valid_completion_signatures = valid_completion_signatures_helper<Signatures>::value;
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/env_of_t.hpp"
+namespace beman::execution {
+
+#line 18 "include/beman/execution/detail/env_of_t.hpp"
+export /* --------- */ template <typename T>
+using env_of_t = decltype(::beman::execution::get_env(::std::declval<T>()));
+} // namespace beman::execution
+
+#line 17 "include/beman/execution/detail/allocator_aware_move.hpp"
+namespace beman::execution::detail {
+template <typename T, typename Context>
+
+#line 24 "include/beman/execution/detail/allocator_aware_move.hpp"
+auto allocator_aware_move(T&& obj, Context&& context) noexcept -> decltype(auto) {
+    try {
+        if constexpr (requires { ::beman::execution::get_allocator(::beman::execution::get_env(context)); }) {
+            if constexpr (decltype(::beman::execution::detail::is_product_type(obj))()) {
+                return obj.make_from(::beman::execution::get_allocator(::beman::execution::get_env(context)),
+                                     ::std::forward<T>(obj));
+            } else {
+                return ::std::make_obj_using_allocator<T>(
+                    ::beman::execution::get_allocator(::beman::execution::get_env(context)), ::std::forward<T>(obj));
+            }
+        } else {
+            return ::std::forward<T>(obj);
+        }
+    } catch (...) {
+        ::std::terminate();
+    }
+}
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/stop_token_of_t.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename T>
+using stop_token_of_t = ::std::remove_cvref_t<decltype(::beman::execution::get_stop_token(::std::declval<T>()))>;
+}
+#line 13 "include/beman/execution/detail/unstoppable_token.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Token>
+concept unstoppable_token = ::beman::execution::stoppable_token<Token> &&
+                            requires() { requires ::std::bool_constant<not Token::stop_possible()>::value; };
+} // namespace beman::execution
+
+#line 13 "include/beman/execution/detail/has_as_awaitable.hpp"
+namespace beman::execution::detail {
+template <typename T, typename Promise>
+concept has_as_awaitable = requires(T&& obj, Promise& promise) {
+    { ::std::forward<T>(obj).as_awaitable(promise) } -> ::beman::execution::detail::is_awaitable<Promise&>;
+};
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/has_completions.hpp"
+namespace beman::execution::detail {
+template <typename Receiver, typename Completions>
+concept has_completions = requires(Completions* completions) {
+    []<::beman::execution::detail::valid_completion_for<Receiver>... Signatures>(
+        ::beman::execution::completion_signatures<Signatures...>*) {}(completions);
+};
+} // namespace beman::execution::detail
+
+#line 23 "include/beman/execution/detail/default_impls.hpp"
+namespace beman::execution::detail {
+
+#line 29 "include/beman/execution/detail/default_impls.hpp"
+struct default_impls {
+    struct get_attrs_impl {
+        auto operator()(const auto&, const auto&... child) const noexcept -> decltype(auto) {
+            if constexpr (1 == sizeof...(child))
+                return (::beman::execution::detail::fwd_env(::beman::execution::get_env(child)), ...);
+            else
+                return ::beman::execution::env<>{};
+        }
+    };
+    static constexpr auto get_attrs = get_attrs_impl{};
+    struct get_env_impl {
+        auto operator()(auto, auto&, const auto& receiver) const noexcept -> decltype(auto) {
+            return ::beman::execution::detail::fwd_env(::beman::execution::get_env(receiver));
+        }
+    };
+    static constexpr auto get_env = get_env_impl{};
+    struct get_state_impl {
+        template <typename Sender, typename Receiver>
+        auto operator()(Sender&& sender, Receiver& receiver) const noexcept -> decltype(auto) {
+            auto&& data{[&sender]() -> decltype(auto) {
+                if constexpr (requires {
+                                  sender.size();
+                                  sender.template get<1>();
+                              })
+                    return sender.template get<1>();
+                else
+                    return ::beman::execution::detail::get_sender_data(::std::forward<Sender>(sender)).data;
+            }()};
+
+            return ::beman::execution::detail::allocator_aware_move(
+                ::beman::execution::detail::forward_like<Sender>(data), receiver);
+        }
+    };
+    static constexpr auto get_state = get_state_impl{};
+    struct start_impl {
+        auto operator()(auto&, auto&, auto&... ops) const noexcept -> void { (::beman::execution::start(ops), ...); }
+    };
+    static constexpr auto start = start_impl{};
+    struct complete_impl {
+        template <typename Index, typename Receiver, typename Tag, typename... Args>
+            requires ::beman::execution::detail::callable<Tag, Receiver, Args...>
+        auto operator()(Index, auto&, Receiver& receiver, Tag, Args&&... args) const noexcept -> void {
+            static_assert(Index::value == 0);
+            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
+        }
+    };
+    static constexpr auto complete = complete_impl{};
+};
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/with_await_transform.hpp"
+namespace beman::execution::detail {
+// NOLINTBEGIN(bugprone-crtp-constructor-accessibility)
+template <typename Derived>
+struct with_await_transform {
+    template <typename T>
+    auto await_transform(T&& obj) noexcept -> T&& {
+        return ::std::forward<T>(obj);
+    }
+#line 23 "include/beman/execution/detail/with_await_transform.hpp"
+    template <::beman::execution::detail::has_as_awaitable<Derived> T>
+    auto await_transform(T&& obj) noexcept(noexcept(::std::forward<T>(obj).as_awaitable(::std::declval<Derived&>())))
+        -> decltype(auto) {
+        return ::std::forward<T>(obj).as_awaitable(static_cast<Derived&>(*this));
+    }
+};
+// NOLINTEND(bugprone-crtp-constructor-accessibility)
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/receiver_of.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Receiver, typename Completions>
+concept receiver_of =
+    beman::execution::receiver<Receiver> && beman::execution::detail::has_completions<Receiver, Completions>;
+}
+#line 15 "include/beman/execution/detail/gather_signatures.hpp"
+namespace beman::execution::detail {
+template <typename...>
+concept always_true = true;
+
+template <typename, typename>
+struct same_tag;
+template <typename Tag, typename R, typename... A>
+struct same_tag<Tag, R(A...)> {
+    static constexpr bool value = ::std::same_as<Tag, R>;
+};
+template <typename Tag>
+struct bound_tag {
+    using type = Tag;
+    template <typename T>
+    using predicate = ::beman::execution::detail::same_tag<Tag, T>;
+};
+
+template <typename, template <typename...> class>
+struct gather_signatures_apply;
+template <typename R, typename... A, template <typename...> class Transform>
+    requires requires {
+        typename ::beman::execution::detail::indirect_meta_apply<
+            ::beman::execution::detail::always_true<R>>::template meta_apply<Transform, A...>;
+    }
+struct gather_signatures_apply<R(A...), Transform> {
+    using type = typename ::beman::execution::detail::indirect_meta_apply<
+        ::beman::execution::detail::always_true<R>>::template meta_apply<Transform, A...>;
+};
+
+template <::beman::execution::detail::valid_completion_signatures,
+          template <typename...> class,
+          template <typename...> class>
+struct gather_signatures_helper;
+
+template <typename... Signatures, template <typename...> class Tuple, template <typename...> class Variant>
+    requires requires {
+        requires always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
+    } && requires {
+        typename ::beman::execution::detail::indirect_meta_apply<
+            always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>>::
+            template meta_apply<
+                Variant,
+                typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
+    }
+struct gather_signatures_helper<::beman::execution::completion_signatures<Signatures...>, Tuple, Variant> {
+    using type = typename ::beman::execution::detail::indirect_meta_apply<
+        always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>>::
+        template meta_apply<Variant,
+                            typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
+};
+
+template <typename Tag,
+          ::beman::execution::detail::valid_completion_signatures signatures,
+          template <typename...> class Tuple,
+          template <typename...> class Variant>
+    requires requires {
+        typename ::beman::execution::detail::gather_signatures_helper<
+            ::beman::execution::detail::meta::filter_tag<::beman::execution::detail::same_tag, Tag, signatures>,
+            Tuple,
+            Variant>::type;
+    }
+using gather_signatures = typename ::beman::execution::detail::gather_signatures_helper<
+    ::beman::execution::detail::meta::filter_tag<::beman::execution::detail::same_tag, Tag, signatures>,
+    Tuple,
+    Variant>::type;
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/env_promise.hpp"
+namespace beman::execution::detail {
+
+#line 19 "include/beman/execution/detail/env_promise.hpp"
+export /* --------- */ template <typename Env>
+struct env_promise : ::beman::execution::detail::with_await_transform<Env> {
+    auto get_return_object() noexcept -> void;
+    auto initial_suspend() noexcept -> ::std::suspend_always;
+    auto final_suspend() noexcept -> ::std::suspend_always;
+    auto unhandled_exception() noexcept -> void;
+    auto return_void() noexcept -> void;
+    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<>;
+    auto get_env() const noexcept -> const Env&;
+};
+} // namespace beman::execution::detail
+
+#line 12 "include/beman/execution/detail/impls_for.hpp"
+namespace beman::execution::detail {
+template <typename Tag>
+struct impls_for : ::beman::execution::detail::default_impls {};
+} // namespace beman::execution::detail
+
+#line 19 "include/beman/execution/detail/operation_state_task.hpp"
+namespace beman::execution::detail {
+template <typename Receiver>
+struct operation_state_task;
+
+template <typename Receiver>
+struct connect_awaitable_promise;
+} // namespace beman::execution::detail
+
+#line 29 "include/beman/execution/detail/operation_state_task.hpp"
+template <typename Receiver>
+struct beman::execution::detail::connect_awaitable_promise
+    : ::beman::execution::detail::with_await_transform<connect_awaitable_promise<Receiver>> {
+    connect_awaitable_promise(auto&&, Receiver& rcvr) noexcept : receiver(rcvr) {}
+    auto              initial_suspend() noexcept -> ::std::suspend_always { return {}; }
+    [[noreturn]] auto final_suspend() noexcept -> ::std::suspend_always { ::std::terminate(); }
+    [[noreturn]] auto unhandled_exception() noexcept -> void { ::std::terminate(); }
+    [[noreturn]] auto return_void() noexcept -> void { ::std::terminate(); }
+
+    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<> {
+        ::beman::execution::set_stopped(::std::move(this->receiver));
+        return ::std::noop_coroutine();
+    }
+#line 43 "include/beman/execution/detail/operation_state_task.hpp"
+    auto get_env() const noexcept -> ::beman::execution::env_of_t<Receiver> {
+        return ::beman::execution::get_env(this->receiver);
+    }
+#line 47 "include/beman/execution/detail/operation_state_task.hpp"
+    auto get_return_object() noexcept -> ::beman::execution::detail::operation_state_task<Receiver>;
+
+  private:
+    Receiver& receiver;
+};
+
+#line 55 "include/beman/execution/detail/operation_state_task.hpp"
+template <typename Receiver>
+struct beman::execution::detail::operation_state_task {
+    using operation_state_concept = ::beman::execution::operation_state_t;
+    using promise_type            = ::beman::execution::detail::connect_awaitable_promise<Receiver>;
+
+    explicit operation_state_task(::std::coroutine_handle<> hndl) noexcept : handle(hndl) {}
+    operation_state_task(const operation_state_task&) = delete;
+    operation_state_task(operation_state_task&& other) noexcept : handle(::std::exchange(other.handle, {})) {}
+    ~operation_state_task() {
+        if (this->handle)
+            this->handle.destroy();
+    }
+    auto operator=(operation_state_task&&) -> operation_state_task&      = delete;
+    auto operator=(const operation_state_task&) -> operation_state_task& = delete;
+
+    auto start() & noexcept -> void { this->handle.resume(); }
+
+    ::std::coroutine_handle<> handle;
+};
+
+#line 77 "include/beman/execution/detail/operation_state_task.hpp"
+template <typename Receiver>
+auto beman::execution::detail::connect_awaitable_promise<Receiver>::get_return_object() noexcept
+    -> ::beman::execution::detail::operation_state_task<Receiver> {
+    return ::beman::execution::detail::operation_state_task<Receiver>(
+        std::coroutine_handle<connect_awaitable_promise>::from_promise(*this));
+}
+#line 18 "include/beman/execution/detail/sender.hpp"
+namespace beman::execution {
+export /* --------- */ struct sender_t {};
+} // namespace beman::execution
+namespace beman::execution::detail {
+template <typename Sender>
+concept is_sender = ::std::derived_from<typename Sender::sender_concept, ::beman::execution::sender_t>;
+
+template <typename Sender>
+concept enable_sender =
+    ::beman::execution::detail::is_sender<Sender> ||
+    ::beman::execution::detail::is_awaitable<Sender,
+                                             ::beman::execution::detail::env_promise<::beman::execution::env<>>>;
+} // namespace beman::execution::detail
+namespace beman::execution {
+export /* --------- */ template <typename Sender>
+concept sender = ::beman::execution::detail::enable_sender<::std::remove_cvref_t<Sender>> &&
+                 requires(const ::std::remove_cvref_t<Sender>& sndr) {
+                     { ::beman::execution::get_env(sndr) } -> ::beman::execution::detail::queryable;
+                 } && ::std::move_constructible<::std::remove_cvref_t<Sender>> &&
+                 ::std::constructible_from<::std::remove_cvref_t<Sender>, Sender>;
+} // namespace beman::execution
+
+#line 24 "include/beman/execution/detail/connect_awaitable.hpp"
+namespace beman::execution::detail {
+
+#line 30 "include/beman/execution/detail/connect_awaitable.hpp"
+template <typename T>
+struct awaiter_set_value {
+    using type = ::beman::execution::set_value_t(T);
+};
+
+#line 39 "include/beman/execution/detail/connect_awaitable.hpp"
+template <>
+struct awaiter_set_value<void> {
+    using type = ::beman::execution::set_value_t();
+};
+
+#line 49 "include/beman/execution/detail/connect_awaitable.hpp"
+template <typename Awaiter, typename Receiver>
+using awaiter_completion_signatures = ::beman::execution::completion_signatures<
+    typename ::beman::execution::detail::awaiter_set_value<::beman::execution::detail::await_result_type<
+        Awaiter,
+        ::beman::execution::detail::connect_awaitable_promise<Receiver>>>::type,
+    ::beman::execution::set_error_t(::std::exception_ptr),
+    ::beman::execution::set_stopped_t()>;
+
+#line 62 "include/beman/execution/detail/connect_awaitable.hpp"
+template <typename Awaiter, ::beman::execution::receiver Receiver>
+auto connect_awaitable(Awaiter awaiter, Receiver receiver)
+    -> ::beman::execution::detail::operation_state_task<Receiver>
+    requires ::beman::execution::
+        receiver_of<Receiver, ::beman::execution::detail::awaiter_completion_signatures<Awaiter, Receiver>>
+{
+
+#line 70 "include/beman/execution/detail/connect_awaitable.hpp"
+    using result_type =
+        ::beman::execution::detail::await_result_type<Awaiter,
+                                                      ::beman::execution::detail::connect_awaitable_promise<Receiver>>;
+
+    ::std::exception_ptr ep;
+    try {
+        if constexpr (std::same_as<void, result_type>) {
+            co_await ::std::move(awaiter);
+            co_await ::beman::execution::detail::suspend_complete(::beman::execution::set_value,
+                                                                  ::std::move(receiver));
+        } else {
+            co_await ::beman::execution::detail::suspend_complete(
+                ::beman::execution::set_value, ::std::move(receiver), co_await ::std::move(awaiter));
+        }
+    } catch (...) {
+        ep = ::std::current_exception();
+    }
+    co_await ::beman::execution::detail::suspend_complete(::beman::execution::set_error, ::std::move(receiver), ep);
+}
+} // namespace beman::execution::detail
+
+#line 16 "include/beman/execution/detail/state_type.hpp"
+namespace beman::execution::detail {
+template <typename Sender, typename Receiver>
+using state_type = ::std::decay_t<::beman::execution::detail::call_result_t<
+    decltype(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_state),
+    Sender,
+    Receiver&>>;
+}
+#line 15 "include/beman/execution/detail/schedule.hpp"
+namespace beman::execution {
+export /* --------- */ struct schedule_t {
+    template <typename Scheduler>
+        requires(not requires(Scheduler&& sched) {
+                    { ::std::forward<Scheduler>(sched).schedule() } -> ::beman::execution::sender;
+                })
+    auto operator()(Scheduler&& sched) const =
+        BEMAN_EXECUTION_DELETE("the scheduler needs a schedule() member returning a sender");
+
+    template <typename Scheduler>
+        requires requires(Scheduler&& sched) {
+            { ::std::forward<Scheduler>(sched).schedule() } -> ::beman::execution::sender;
+        }
+    auto operator()(Scheduler&& sched) const noexcept(noexcept(std::forward<Scheduler>(sched).schedule())) {
+        return std::forward<Scheduler>(sched).schedule();
+    }
+};
+
+export /* --------- */ inline constexpr ::beman::execution::schedule_t schedule{};
+} // namespace beman::execution
+
+#line 15 "include/beman/execution/detail/sender_adaptor_closure.hpp"
+namespace beman::execution::detail::pipeable {
+struct sender_adaptor_closure_base {};
+} // namespace beman::execution::detail::pipeable
+
+namespace beman::execution {
+// NOLINTBEGIN(bugprone-crtp-constructor-accessibility)
+export /* --------- */ template <typename>
+struct sender_adaptor_closure : ::beman::execution::detail::pipeable::sender_adaptor_closure_base {};
+// NOLINTEND(bugprone-crtp-constructor-accessibility)
+
+} // namespace beman::execution
+
+namespace beman::execution::detail {
+template <typename Closure>
+concept is_sender_adaptor_closure =
+    ::std::derived_from<::std::decay_t<Closure>, ::beman::execution::sender_adaptor_closure<::std::decay_t<Closure>>>;
+}
+#line 33 "include/beman/execution/detail/sender_adaptor_closure.hpp"
+namespace beman::execution::detail::pipeable {
+export /* --------- */ template <::beman::execution::sender Sender, typename Adaptor>
+    requires(!::beman::execution::sender<Adaptor>) &&
+            ::std::derived_from<::std::decay_t<Adaptor>,
+                                ::beman::execution::sender_adaptor_closure<::std::decay_t<Adaptor>>> &&
+            requires(Sender&& sender, Adaptor&& adaptor) {
+                { adaptor(::std::forward<Sender>(sender)) } -> ::beman::execution::sender;
+            }
+auto operator|(Sender&& sender, Adaptor&& adaptor) {
+    return adaptor(::std::forward<Sender>(sender));
+}
+} // namespace beman::execution::detail::pipeable
+
+#line 15 "include/beman/execution/detail/sender_for.hpp"
+namespace beman::execution::detail {
+template <typename Sender, typename Tag>
+concept sender_for = ::beman::execution::sender<Sender> && ::std::same_as<::beman::execution::tag_of_t<Sender>, Tag>;
+}
+#line 14 "include/beman/execution/detail/sender_has_affine_on.hpp"
+namespace beman::execution::detail {
+template <typename Sender, typename Env>
+concept sender_has_affine_on =
+    beman::execution::sender<::std::remove_cvref_t<Sender>> && requires(Sender&& sndr, const Env& env) {
+        sndr.template get<0>();
+        { sndr.template get<0>().affine_on(std::forward<Sender>(sndr), env) } -> ::beman::execution::sender;
+    };
+} // namespace beman::execution::detail
+
+#line 17 "include/beman/execution/detail/default_domain.hpp"
+namespace beman::execution {
+
+#line 28 "include/beman/execution/detail/default_domain.hpp"
+export /* --------- */ struct default_domain {
+    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable... Env>
+        requires(sizeof...(Env) <= 1) && requires(Sender&& sender, Env&&... env) {
+            ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
+                                                                    ::std::forward<Env>(env)...);
+        }
+    static constexpr auto transform_sender(Sender&& sender, Env&&... env) noexcept(
+        noexcept(::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
+                                                                         ::std::forward<Env>(env)...)))
+        -> ::beman::execution::sender decltype(auto) {
+        return ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
+                                                                       ::std::forward<Env>(env)...);
+    }
+#line 42 "include/beman/execution/detail/default_domain.hpp"
+    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable... Env>
+        requires(sizeof...(Env) <= 1) && (not requires(Sender&& sender, Env&&... env) {
+                    ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
+                                                                            ::std::forward<Env>(env)...);
+                })
+    static constexpr auto transform_sender(Sender&& sender,
+                                           Env&&...) noexcept(noexcept(::std::forward<Sender>(sender)))
+        -> ::beman::execution::sender decltype(auto) {
+        return ::std::forward<Sender>(sender);
+    }
+#line 53 "include/beman/execution/detail/default_domain.hpp"
+    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
+        requires requires(Sender&& sender, Env&& env) {
+            ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
+                                                                 ::std::forward<Env>(env));
+        }
+    static constexpr auto transform_env(Sender&& sender, Env&& env) noexcept -> ::beman::execution::detail::queryable
+        decltype(auto) {
+        return ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
+                                                                    ::std::forward<Env>(env));
+    }
+#line 64 "include/beman/execution/detail/default_domain.hpp"
+    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
+        requires(not requires(Sender&& sender, Env&& env) {
+            ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
+                                                                 ::std::forward<Env>(env));
+        })
+    static constexpr auto transform_env(Sender&&, Env&& env) noexcept -> ::beman::execution::detail::queryable
+        decltype(auto) {
+        return static_cast<Env>(::std::forward<Env>(env));
+    }
+#line 74 "include/beman/execution/detail/default_domain.hpp"
+    template <typename Tag, ::beman::execution::sender Sender, typename... Args>
+        requires requires(Sender&& sender, Args&&... args) {
+            Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
+        }
+    static constexpr auto apply_sender(Tag, Sender&& sender, Args&&... args) noexcept(noexcept(
+        Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...))) -> decltype(auto) {
+        return Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
+    }
+};
+} // namespace beman::execution
+
+#line 18 "include/beman/execution/detail/spawn_get_allocator.hpp"
+namespace beman::execution::detail {
+template <::beman::execution::sender Sndr, typename Ev>
+auto spawn_get_allocator(const Sndr& sndr, const Ev& ev) {
+    if constexpr (requires { ::beman::execution::get_allocator(ev); }) {
+        return ::std::pair(::beman::execution::get_allocator(ev), ev);
+    } else if constexpr (requires { ::beman::execution::get_allocator(::beman::execution::get_env(sndr)); }) {
+        auto alloc{::beman::execution::get_allocator(::beman::execution::get_env(sndr))};
+        return ::std::pair(alloc,
+                           ::beman::execution::detail::join_env(
+                               ::beman::execution::prop(::beman::execution::get_allocator, alloc), ev));
+    } else {
+        return ::std::pair(::std::allocator<void>{}, ev);
+    }
+}
+#line 33 "include/beman/execution/detail/spawn_get_allocator.hpp"
+} // namespace beman::execution::detail
+
+#line 17 "include/beman/execution/detail/basic_state.hpp"
+namespace beman::execution::detail {
+
+#line 24 "include/beman/execution/detail/basic_state.hpp"
+export /* --------- */ template <typename Sender, typename Receiver>
+struct basic_state {
+    basic_state(Sender&& sender, Receiver&& rcvr) noexcept(true)
+        : receiver(::std::move(rcvr)),
+          state(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_state(
+              ::std::forward<Sender>(sender), this->receiver)) {}
+
+    Receiver                                                 receiver;
+    ::beman::execution::detail::state_type<Sender, Receiver> state;
+};
+template <typename Sender, typename Receiver>
+basic_state(Sender&&, Receiver&&) -> basic_state<Sender&&, Receiver>;
+} // namespace beman::execution::detail
+
+#line 16 "include/beman/execution/detail/env_type.hpp"
+namespace beman::execution::detail {
+
+#line 22 "include/beman/execution/detail/env_type.hpp"
+template <typename Index, typename Sender, typename Receiver>
+using env_type = ::beman::execution::detail::call_result_t<
+    decltype(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_env),
+    Index,
+    ::beman::execution::detail::state_type<Sender, Receiver>&,
+    const Receiver&>;
+} // namespace beman::execution::detail
+
+#line 17 "include/beman/execution/detail/almost_scheduler.hpp"
+namespace beman::execution::detail {
+
+#line 24 "include/beman/execution/detail/almost_scheduler.hpp"
+template <typename Scheduler>
+concept almost_scheduler = ::std::derived_from<typename ::std::remove_cvref_t<Scheduler>::scheduler_concept,
+                                               ::beman::execution::scheduler_t> &&
+                           ::beman::execution::detail::queryable<Scheduler> &&
+                           requires(Scheduler&& sched) {
+                               {
+                                   ::beman::execution::schedule(::std::forward<Scheduler>(sched))
+                               } -> ::beman::execution::sender;
+                           } && ::std::equality_comparable<::std::remove_cvref_t<Scheduler>> &&
+                           ::std::copy_constructible<::std::remove_cvref_t<Scheduler>>;
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/transform_sender.hpp"
+namespace beman::execution::detail {
+template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+    requires(sizeof...(Env) < 2) &&
+            requires(Domain dom, Sender&& sender, const Env&... env) {
+                dom.transform_sender(::std::forward<Sender>(sender), env...);
+            } &&
+            (::std::same_as<::std::remove_cvref_t<Sender>,
+                            std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
+                                ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
+constexpr auto transform_sender(Domain, Sender&& sender, const Env&...) noexcept -> ::beman::execution::sender auto {
+    return ::std::forward<Sender>(sender);
+}
+#line 27 "include/beman/execution/detail/transform_sender.hpp"
+template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+    requires(sizeof...(Env) < 2) &&
+            requires(Domain dom, Sender&& sender, const Env&... env) {
+                dom.transform_sender(::std::forward<Sender>(sender), env...);
+            } &&
+            (!::std::same_as<::std::remove_cvref_t<Sender>,
+                             std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
+                                 ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
+constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept -> ::beman::execution::sender
+    decltype(auto) {
+    return ::beman::execution::detail::transform_sender(
+        dom, dom.transform_sender(::std::forward<Sender>(sender), env...), env...);
+}
+#line 41 "include/beman/execution/detail/transform_sender.hpp"
+template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+    requires(not requires(Domain dom, Sender&& sender, const Env&... env) {
+                dom.transform_sender(::std::forward<Sender>(sender), env...);
+            }) && ::std::same_as<::std::remove_cvref_t<Sender>,
+                                 ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
+                                     ::std::declval<Sender>(), ::std::declval<Env>()...))>>
+constexpr auto
+    transform_sender(Domain, Sender&& sender, const Env&...) noexcept(noexcept(::std::forward<Sender>(sender)))
+        -> ::beman::execution::sender auto {
+    return sender;
+}
+#line 53 "include/beman/execution/detail/transform_sender.hpp"
+template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+    requires(not requires(Domain dom, Sender&& sender, const Env&... env) {
+                dom.transform_sender(::std::forward<Sender>(sender), env...);
+            }) &&
+            (!::std::same_as<::std::remove_cvref_t<Sender>,
+                             ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
+                                 ::std::declval<Sender>(), ::std::declval<Env>()...))>>)
+constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept(noexcept(
+    ::beman::execution::default_domain{}.transform_sender(::std::declval<Sender>(), ::std::declval<Env>()...)))
+    -> ::beman::execution::sender decltype(auto) {
+    return ::beman::execution::detail::transform_sender(
+        dom, ::beman::execution::default_domain{}.transform_sender(::std::forward<Sender>(sender), env...), env...);
+}
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+    requires(sizeof...(Env) < 2) &&
+            requires(Domain dom, Sender&& sender, const Env&... env) {
+                dom.transform_sender(::std::forward<Sender>(sender), env...);
+            } &&
+            (::std::same_as<::std::remove_cvref_t<Sender>,
+                            std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
+                                ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
+constexpr auto transform_sender(Domain, Sender&& sender, const Env&...) noexcept -> ::beman::execution::sender
+    decltype(auto) {
+    return ::std::forward<Sender>(sender);
+}
+#line 82 "include/beman/execution/detail/transform_sender.hpp"
+export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+    requires(sizeof...(Env) < 2) &&
+            requires(Domain dom, Sender&& sender, const Env&... env) {
+                dom.transform_sender(::std::forward<Sender>(sender), env...);
+            } &&
+            (!::std::same_as<::std::remove_cvref_t<Sender>,
+                             std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
+                                 ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
+constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept -> ::beman::execution::sender
+    auto {
+    return ::beman::execution::detail::transform_sender(
+        dom, dom.transform_sender(::std::forward<Sender>(sender), env...), env...);
+}
+#line 96 "include/beman/execution/detail/transform_sender.hpp"
+export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+    requires(sizeof...(Env) < 2) && (not requires(Domain dom, Sender&& sender, const Env&... env) {
+                dom.transform_sender(::std::forward<Sender>(sender), env...);
+            }) &&
+            ::std::same_as<::std::remove_cvref_t<Sender>,
+                           ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
+                               ::std::declval<Sender>(), ::std::declval<Env>()...))>>
+constexpr auto
+    transform_sender(Domain, Sender&& sender, const Env&...) noexcept(noexcept(::std::forward<Sender>(sender)))
+        -> ::beman::execution::sender decltype(auto) {
+    return ::std::forward<Sender>(sender);
+}
+#line 109 "include/beman/execution/detail/transform_sender.hpp"
+export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+    requires(sizeof...(Env) < 2) && (not requires(Domain dom, Sender&& sender, const Env&... env) {
+                dom.transform_sender(::std::forward<Sender>(sender), env...);
+            }) &&
+            (!::std::same_as<::std::remove_cvref_t<Sender>,
+                             ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
+                                 ::std::declval<Sender>(), ::std::declval<Env>()...))>>)
+constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept(
+    noexcept(::beman::execution::detail::transform_sender(
+        dom,
+        ::beman::execution::default_domain{}.transform_sender(::std::declval<Sender>(), ::std::declval<Env>()...),
+        env...))) -> ::beman::execution::sender decltype(auto) {
+    return ::beman::execution::detail::transform_sender(
+        dom, ::beman::execution::default_domain{}.transform_sender(::std::forward<Sender>(sender), env...), env...);
+}
+} // namespace beman::execution
+
+#line 18 "include/beman/execution/detail/sender_adaptor.hpp"
+namespace beman::execution::detail {
+export /* --------- */ template <typename Adaptor, typename... T>
+struct sender_adaptor : ::beman::execution::detail::product_type<::std::decay_t<Adaptor>, ::std::decay_t<T>...>,
+                        ::beman::execution::sender_adaptor_closure<sender_adaptor<Adaptor, T...>> {
+    template <::beman::execution::sender Sender, typename Self>
+    static auto apply(Sender&& sender, Self&& self) {
+        return [&self, &sender]<::std::size_t... I>(::std::index_sequence<I...>) {
+            auto&& fun(self.template get<0>());
+            return fun(::std::forward<Sender>(sender),
+                       ::beman::execution::detail::forward_like<Self>(self.template get<I + 1>())...);
+        }(::std::make_index_sequence<sender_adaptor::size() - 1u>{});
+    }
+    template <::beman::execution::sender Sender>
+    auto operator()(Sender&& sender) {
+        return apply(::std::forward<Sender>(sender), ::std::move(*this));
+    }
+    template <::beman::execution::sender Sender>
+    auto operator()(Sender&& sender) const {
+        return apply(::std::forward<Sender>(sender), *this);
+    }
+};
+template <typename... T>
+sender_adaptor(T&&...) -> sender_adaptor<T...>;
+} // namespace beman::execution::detail
+
+#line 16 "include/beman/execution/detail/sched_env.hpp"
+namespace beman::execution::detail {
+template <typename Scheduler>
+class sched_env {
+  private:
+    Scheduler sched;
+
+  public:
+    template <typename S>
+    explicit sched_env(S sch) : sched(::std::move(sch)) {}
+
+    auto query(const ::beman::execution::get_scheduler_t&) const noexcept { return this->sched; }
+    auto query(const ::beman::execution::get_domain_t& q) const noexcept {
+        if constexpr (requires { this->sched.query(q); })
+            return this->sched.query(q);
+        else
+            return ::beman::execution::default_domain{};
+    }
+};
+
+template <typename Scheduler>
+sched_env(Scheduler&&) -> sched_env<::std::remove_cvref_t<Scheduler>>;
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/apply_sender.hpp"
+namespace beman::execution {
+
+#line 19 "include/beman/execution/detail/apply_sender.hpp"
+export /* --------- */ template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
+    requires requires(Domain domain, Tag tag, Sender&& sender, Args&&... args) {
+        domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
+    }
+constexpr auto apply_sender(Domain domain, Tag, Sender&& sender, Args&&... args) noexcept(noexcept(
+    domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...))) -> decltype(auto) {
+    return domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
+}
+#line 32 "include/beman/execution/detail/apply_sender.hpp"
+export /* --------- */ template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
+    requires(not requires(Domain domain, Tag tag, Sender&& sender, Args&&... args) {
+                domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
+            }) && requires(Tag tag, Sender&& sender, Args&&... args) {
+        beman::execution::default_domain().apply_sender(
+            Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
+    }
+constexpr auto apply_sender(Domain, Tag, Sender&& sender, Args&&... args) noexcept(
+    noexcept(beman::execution::default_domain().apply_sender(Tag(),
+                                                             ::std::forward<Sender>(sender),
+                                                             ::std::forward<Args>(args)...))) -> decltype(auto) {
+    return beman::execution::default_domain().apply_sender(
+        Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
+}
+#line 47 "include/beman/execution/detail/apply_sender.hpp"
+} // namespace beman::execution
+
+#line 12 "include/beman/execution/detail/nested_sender_has_affine_on.hpp"
+namespace beman::execution::detail {
+template <typename Sender, typename Env>
+concept nested_sender_has_affine_on = requires(Sender&& sndr, const Env& env) {
+    { sndr.template get<2>() } -> ::beman::execution::detail::sender_has_affine_on<Env>;
+};
+} // namespace beman::execution::detail
+
+#line 25 "include/beman/execution/detail/basic_receiver.hpp"
+namespace beman::execution::detail {
+
+#line 31 "include/beman/execution/detail/basic_receiver.hpp"
+template <typename Sender, typename Receiver, typename Index>
+    requires ::beman::execution::detail::
+        valid_specialization<::beman::execution::detail::env_type, Index, Sender, Receiver>
+    struct basic_receiver {
+    friend struct ::beman::execution::get_env_t;
+    friend struct ::beman::execution::set_error_t;
+    friend struct ::beman::execution::set_stopped_t;
+    friend struct ::beman::execution::set_value_t;
+
+    using receiver_concept                = ::beman::execution::receiver_t;
+    using tag_t                           = ::beman::execution::tag_of_t<Sender>;
+    using state_t                         = ::beman::execution::detail::state_type<Sender, Receiver>;
+    static constexpr const auto& complete = ::beman::execution::detail::impls_for<tag_t>::complete;
+    ::beman::execution::detail::basic_state<Sender, Receiver>* op{};
+
+  private:
+    template <typename... Args>
+    auto set_value(Args&&... args) && noexcept -> void
+        requires ::beman::execution::detail::
+            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_value_t, Args...>
+    {
+        this->complete(Index(),
+                       this->op->state,
+                       this->op->receiver,
+                       ::beman::execution::set_value_t(),
+                       ::std::forward<Args>(args)...);
+    }
+#line 59 "include/beman/execution/detail/basic_receiver.hpp"
+    template <typename Error>
+    auto set_error(Error&& error) && noexcept -> void
+        requires ::beman::execution::detail::
+            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_error_t, Error>
+    {
+        this->complete(Index(),
+                       this->op->state,
+                       this->op->receiver,
+                       ::beman::execution::set_error_t(),
+                       ::std::forward<Error>(error));
+    }
+#line 71 "include/beman/execution/detail/basic_receiver.hpp"
+    auto set_stopped() && noexcept -> void
+        requires ::beman::execution::detail::
+            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_stopped_t>
+    {
+        this->complete(Index(), this->op->state, this->op->receiver, ::beman::execution::set_stopped_t());
+    }
+#line 78 "include/beman/execution/detail/basic_receiver.hpp"
+    auto get_env() const noexcept -> ::beman::execution::detail::env_type<Index, Sender, Receiver> {
+        return ::beman::execution::detail::impls_for<tag_t>::get_env(Index(), this->op->state, this->op->receiver);
+    }
+};
+} // namespace beman::execution::detail
+
+#line 25 "include/beman/execution/detail/get_completion_scheduler.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Tag>
+struct get_completion_scheduler_t;
+
+template <typename Tag>
+struct get_completion_scheduler_t : ::beman::execution::forwarding_query_t {
+    template <typename Env>
+        requires(not requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
+                    env.query(self);
+                })
+    auto operator()(Env&&) const noexcept =
+        BEMAN_EXECUTION_DELETE("The environment needs a query(get_completion_scheduler_t) member");
+
+    template <typename Env>
+        requires(requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
+                    env.query(self);
+                } && (not requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
+                     { env.query(self) } noexcept;
+                 }))
+    auto operator()(Env&&) const noexcept =
+        BEMAN_EXECUTION_DELETE("The environment's query(get_completion_scheduler_t) has to be noexcept");
+
+    template <typename Env>
+        requires(
+                    requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
+                        env.query(self);
+                    } &&
+                    requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
+                        { env.query(self) } noexcept;
+                    } &&
+                    (not requires(const get_completion_scheduler_t&                                  self,
+                                  const get_completion_scheduler_t<::beman::execution::set_value_t>& value_self,
+                                  const ::std::remove_cvref_t<Env>&                                  env) {
+                        { env.query(self) } noexcept -> ::beman::execution::detail::almost_scheduler;
+                        {
+                            ::beman::execution::get_env(::beman::execution::schedule(env.query(self)))
+                                .query(value_self)
+                        } -> ::beman::execution::detail::decayed_same_as<decltype(env.query(self))>;
+                    }))
+    auto operator()(Env&&) const noexcept =
+        BEMAN_EXECUTION_DELETE("The environment's query(get_completion_scheduler_t) has to return a scheduler");
+
+    template <typename Env>
+        requires requires(const get_completion_scheduler_t&                                  self,
+                          const get_completion_scheduler_t<::beman::execution::set_value_t>& value_self,
+                          const ::std::remove_cvref_t<Env>&                                  env) {
+            { env.query(self) } noexcept -> ::beman::execution::detail::almost_scheduler;
+            {
+                ::beman::execution::get_env(::beman::execution::schedule(env.query(self))).query(value_self)
+            } -> ::beman::execution::detail::decayed_same_as<decltype(env.query(self))>;
+        }
+    auto operator()(Env&& env) const noexcept {
+        return ::std::as_const(env).query(*this);
+    }
+};
+
+export /* --------- */ template <::beman::execution::detail::completion_tag Tag>
+inline constexpr get_completion_scheduler_t<Tag> get_completion_scheduler{};
+} // namespace beman::execution
+
+#line 19 "include/beman/execution/detail/scheduler.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Scheduler>
+concept scheduler = ::beman::execution::detail::almost_scheduler<Scheduler> && requires(Scheduler&& sched) {
+    {
+        ::beman::execution::get_completion_scheduler<::beman::execution::set_value_t>(
+            ::beman::execution::get_env(::beman::execution::schedule(::std::forward<Scheduler>(sched))))
+    } -> ::beman::execution::detail::decayed_same_as<Scheduler>;
+};
+} // namespace beman::execution
+
+#line 19 "include/beman/execution/detail/sched_attrs.hpp"
+namespace beman::execution::detail {
+
+template <typename Scheduler>
+class sched_attrs {
+  private:
+    Scheduler sched;
+
+  public:
+    template <typename S>
+        requires(!::std::same_as<sched_attrs, ::std::remove_cvref_t<S>>)
+    explicit sched_attrs(S&& s) : sched(::std::forward<S>(s)) {}
+
+    template <typename Tag>
+    auto query(const ::beman::execution::get_completion_scheduler_t<Tag>&) const noexcept {
+        return this->sched;
+    }
+#line 36 "include/beman/execution/detail/sched_attrs.hpp"
+    template <typename T = bool>
+        requires requires(Scheduler&& s) { s.query(::beman::execution::get_domain); }
+    auto query(const ::beman::execution::get_domain_t& q, T = true) const noexcept {
+        return this->sched.query(q);
+    }
+};
+
+template <typename Scheduler>
+sched_attrs(Scheduler&&) -> sched_attrs<::std::remove_cvref_t<Scheduler>>;
+} // namespace beman::execution::detail
+
+#line 17 "include/beman/execution/detail/completion_domain.hpp"
+namespace beman::execution::detail {
+struct completion_domain_undefined {};
+template <typename, typename>
+struct completion_domain_merge {};
+template <typename T>
+struct completion_domain_merge<T, T> {
+    using type = T;
+};
+template <typename T>
+struct completion_domain_merge<completion_domain_undefined, T> {
+    using type = T;
+};
+template <typename T>
+struct completion_domain_merge<T, completion_domain_undefined> {
+    using type = T;
+};
+template <>
+struct completion_domain_merge<completion_domain_undefined, completion_domain_undefined> {
+    using type = completion_domain_undefined;
+};
+
+#line 43 "include/beman/execution/detail/completion_domain.hpp"
+template <typename Default = ::beman::execution::default_domain, typename Sender>
+constexpr auto completion_domain(const Sender& sender) noexcept {
+
+    static_assert(::beman::execution::sender<Sender>);
+    constexpr auto get = []<typename Tag>(Tag, const Sender& sender) {
+        if constexpr (requires {
+                          ::beman::execution::get_domain(
+                              ::beman::execution::get_completion_scheduler<Tag>(::beman::execution::get_env(sender)));
+                      }) {
+            return ::beman::execution::get_domain(
+                ::beman::execution::get_completion_scheduler<Tag>(::beman::execution::get_env(sender)));
+        } else {
+            return completion_domain_undefined{};
+        }
+    };
+
+    using type = typename completion_domain_merge<
+        typename completion_domain_merge<decltype(get(::beman::execution::set_error, sender)),
+                                         decltype(get(::beman::execution::set_stopped, sender))>::type,
+        decltype(get(::beman::execution::set_value, sender))>::type;
+    return ::std::conditional_t<::std::same_as<type, completion_domain_undefined>, Default, type>();
+}
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/get_delegation_scheduler.hpp"
+namespace beman::execution {
+export /* --------- */ struct get_delegation_scheduler_t {
+    template <typename Env>
+        requires requires(Env&& env, const get_delegation_scheduler_t& g) {
+            { ::std::as_const(env).query(g) } noexcept -> ::beman::execution::scheduler;
+        }
+    auto operator()(Env&& env) const noexcept {
+        return ::std::as_const(env).query(*this);
+    }
+    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
+};
+
+export /* --------- */ inline constexpr get_delegation_scheduler_t get_delegation_scheduler{};
+} // namespace beman::execution
+
+#line 19 "include/beman/execution/detail/get_domain_late.hpp"
+namespace beman::execution::detail {
+template <typename T>
+concept not_void = !::std::same_as<T, void>;
+
+template <typename Tag>
+struct get_domain_late_helper {
+    template <typename Sender, typename Env>
+    static constexpr auto get(const Sender& sender, const Env& env) noexcept {
+        if constexpr (requires {
+                          {
+                              ::beman::execution::get_domain(::beman::execution::get_env(sender))
+                          } -> ::beman::execution::detail::not_void;
+                      })
+            return ::beman::execution::get_domain(::beman::execution::get_env(sender));
+        else if constexpr (requires {
+                               {
+                                   ::beman::execution::detail::completion_domain<void>(sender)
+                               } -> ::beman::execution::detail::not_void;
+                           })
+            return ::beman::execution::detail::completion_domain<void>(sender);
+        else if constexpr (requires {
+                               { ::beman::execution::get_domain(env) } -> ::beman::execution::detail::not_void;
+                           })
+            return ::beman::execution::get_domain(env);
+        else if constexpr (requires {
+                               {
+                                   ::beman::execution::get_domain(::beman::execution::get_scheduler(env))
+                               } -> ::beman::execution::detail::not_void;
+                           })
+            return ::beman::execution::get_domain(::beman::execution::get_scheduler(env));
+        else
+            return ::beman::execution::default_domain();
+    }
+};
+template <typename Sender, typename Env>
+constexpr auto get_domain_late(const Sender& sender, const Env& env) noexcept {
+    using tag_t = ::beman::execution::tag_of_t<Sender>;
+    return ::beman::execution::detail::get_domain_late_helper<tag_t>::get(sender, env);
+}
+} // namespace beman::execution::detail
+
+#line 15 "include/beman/execution/detail/get_domain_early.hpp"
+namespace beman::execution::detail {
+template <typename Sender>
+constexpr auto get_domain_early(const Sender& sender) noexcept {
+    if constexpr (requires { ::beman::execution::get_domain(::beman::execution::get_env(sender)); })
+        return decltype(::beman::execution::get_domain(::beman::execution::get_env(sender))){};
+    else if constexpr (requires { ::beman::execution::detail::completion_domain(sender); })
+        return decltype(::beman::execution::detail::completion_domain(sender)){};
+    else
+        return ::beman::execution::default_domain{};
+}
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/schedule_result_t.hpp"
+namespace beman::execution {
+export /* --------- */ template <::beman::execution::scheduler Scheduler>
+using schedule_result_t = decltype(::beman::execution::schedule(::std::declval<Scheduler>()));
+}
+#line 28 "include/beman/execution/detail/run_loop.hpp"
+namespace beman::execution {
+export /* --------- */ class run_loop {
+  private:
+    struct scheduler;
+
+    struct env {
+        run_loop* loop;
+
+        template <typename Completion>
+        auto query(const ::beman::execution::get_completion_scheduler_t<Completion>&) const noexcept -> scheduler {
+            return {this->loop};
+        }
+    };
+
+    struct opstate_base : ::beman::execution::detail::virtual_immovable {
+        opstate_base* next{};
+        virtual auto  execute() noexcept -> void = 0;
+    };
+
+    template <typename Receiver>
+    struct opstate : opstate_base {
+        using operation_state_concept = ::beman::execution::operation_state_t;
+
+        run_loop* loop;
+        Receiver  receiver;
+
+        // NOLINTBEGIN(misc-no-recursion)
+        template <typename R>
+        opstate(run_loop* l, R&& rcvr) : loop(l), receiver(::std::forward<Receiver>(rcvr)) {}
+        auto start() & noexcept -> void { this->loop->push_back(this); }
+        // NOLINTEND(misc-no-recursion)
+        auto execute() noexcept -> void override {
+            using token = decltype(::beman::execution::get_stop_token(::beman::execution::get_env(this->receiver)));
+            if constexpr (not ::beman::execution::unstoppable_token<token>) {
+                if (::beman::execution::get_stop_token(::beman::execution::get_env(this->receiver)).stop_requested())
+                    ::beman::execution::set_stopped(::std::move(this->receiver));
+                else
+                    ::beman::execution::set_value(::std::move(this->receiver));
+            } else
+                ::beman::execution::set_value(::std::move(this->receiver));
+        }
+    };
+    struct sender {
+        using sender_concept = ::beman::execution::sender_t;
+        template <typename Env = ::beman::execution::env<>>
+        auto get_completion_signatures(Env&& env) const noexcept {
+            if constexpr (::beman::execution::unstoppable_token<decltype(::beman::execution::get_stop_token(env))>)
+                return ::beman::execution::completion_signatures<::beman::execution::set_value_t()>{};
+            else
+                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(),
+                                                                 ::beman::execution::set_stopped_t()>{};
+        }
+#line 81 "include/beman/execution/detail/run_loop.hpp"
+        run_loop* loop;
+
+        auto get_env() const noexcept -> env { return {this->loop}; }
+        template <typename Receiver>
+        auto connect(Receiver&& receiver) noexcept -> opstate<::std::decay_t<Receiver>> {
+            return {this->loop, ::std::forward<Receiver>(receiver)};
+        }
+    };
+    struct scheduler {
+        using scheduler_concept = ::beman::execution::scheduler_t;
+
+        run_loop* loop;
+
+        auto schedule() noexcept -> sender { return {this->loop}; }
+        auto operator==(const scheduler&) const -> bool = default;
+    };
+
+    enum class state : unsigned char { starting, running, finishing };
+
+    state                     current_state{state::starting};
+    ::std::mutex              mutex{};
+    ::std::condition_variable condition{};
+    opstate_base*             front{};
+    opstate_base*             back{};
+
+    auto push_back(opstate_base* item) noexcept -> void {
+
+        ::std::lock_guard guard(this->mutex);
+        if (auto previous_back{::std::exchange(this->back, item)}) {
+            previous_back->next = item;
+        } else {
+            this->front = item;
+            this->condition.notify_one();
+        }
+    }
+    auto pop_front() noexcept -> opstate_base* {
+
+        ::std::unique_lock guard(this->mutex);
+        this->condition.wait(guard, [this] { return this->front || this->current_state == state::finishing; });
+        if (this->front == this->back)
+            this->back = nullptr;
+        return this->front ? ::std::exchange(this->front, this->front->next) : nullptr;
+    }
+#line 125 "include/beman/execution/detail/run_loop.hpp"
+  public:
+    run_loop() noexcept       = default;
+    run_loop(const run_loop&) = delete;
+    run_loop(run_loop&&)      = delete;
+    ~run_loop() {
+        ::std::lock_guard guard(this->mutex);
+        if (this->front != nullptr || this->current_state == state::running)
+            ::std::terminate();
+    }
+    auto operator=(const run_loop&) -> run_loop& = delete;
+    auto operator=(run_loop&&) -> run_loop&      = delete;
+
+    auto get_scheduler() -> scheduler { return {this}; }
+
+    auto run() -> void {
+        if (::std::lock_guard guard(this->mutex);
+            this->current_state != state::finishing &&
+            state::running == ::std::exchange(this->current_state, state::running)) {
+            ::std::terminate();
+        }
+#line 146 "include/beman/execution/detail/run_loop.hpp"
+        while (auto* op{this->pop_front()}) {
+            op->execute();
+        }
+    }
+    auto finish() -> void {
+        {
+            ::std::lock_guard guard(this->mutex);
+            this->current_state = state::finishing;
+        }
+        this->condition.notify_one();
+    }
+};
+} // namespace beman::execution
+
+#line 22 "include/beman/execution/detail/get_completion_signatures.hpp"
+namespace beman::execution {
+export /* --------- */ struct get_completion_signatures_t {
+  private:
+    template <typename Sender, typename Env>
+    static auto get(Sender&& sender, Env&& env) noexcept {
+        auto new_sender{[](auto&& sndr, auto&& e) -> decltype(auto) {
+            auto domain{::beman::execution::detail::get_domain_late(sndr, e)};
+            return ::beman::execution::transform_sender(domain, ::std::forward<Sender>(sndr), ::std::forward<Env>(e));
+        }};
+
+        using sender_type = ::std::remove_cvref_t<decltype(new_sender(sender, env))>;
+        using decayed_env = ::std::remove_cvref_t<Env>;
+        if constexpr (requires { new_sender(sender, env).get_completion_signatures(env); })
+            return decltype(new_sender(sender, env).get_completion_signatures(env)){};
+        else if constexpr (requires { typename sender_type::completion_signatures; })
+            return typename sender_type::completion_signatures{};
+        else if constexpr (::beman::execution::detail::
+                               is_awaitable<sender_type, ::beman::execution::detail::env_promise<decayed_env>>) {
+            using result_type =
+                ::beman::execution::detail::await_result_type<sender_type,
+                                                              ::beman::execution::detail::env_promise<decayed_env>>;
+            if constexpr (::std::same_as<void, result_type>) {
+                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(),
+                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
+                                                                 ::beman::execution::set_stopped_t()>{};
+            } else {
+                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(result_type),
+                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
+                                                                 ::beman::execution::set_stopped_t()>{};
+            }
+        }
+    }
+#line 55 "include/beman/execution/detail/get_completion_signatures.hpp"
+  public:
+    template <typename Sender, typename Env>
+        requires(!::std::same_as<void,
+                                 decltype(get_completion_signatures_t::get(::std::declval<Sender>(),
+                                                                           ::std::declval<Env>()))>)
+    auto operator()(Sender&& sender, Env&& env) const noexcept {
+        return this->get(::std::forward<Sender>(sender), ::std::forward<Env>(env));
+    }
+};
+export /* --------- */ inline constexpr get_completion_signatures_t get_completion_signatures{};
+} // namespace beman::execution
+
+#line 18 "include/beman/execution/detail/connect.hpp"
+namespace beman::execution::detail {
+
+#line 25 "include/beman/execution/detail/connect.hpp"
+export /* --------- */ struct connect_t {
+  private:
+    template <typename Sender, typename Receiver>
+    static auto make_new_sender(Sender&& sender, Receiver&& receiver)
+
+        noexcept(true) -> decltype(auto) {
+        return ::beman::execution::transform_sender(
+            decltype(::beman::execution::detail::get_domain_late(::std::forward<Sender>(sender),
+                                                                 ::beman::execution::get_env(receiver))){},
+            ::std::forward<Sender>(sender),
+            ::beman::execution::get_env(receiver));
+    }
+    template <typename Sender, typename Receiver>
+    static constexpr auto connect_noexcept() -> bool {
+        if constexpr (requires {
+                          make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>())
+                              .connect(::std::declval<Receiver>());
+                      }) {
+            return noexcept(make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>())
+                                .connect(::std::declval<Receiver>()));
+        } else if constexpr (requires {
+                                 ::beman::execution::detail::connect_awaitable(
+                                     make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>()),
+                                     ::std::declval<Receiver>());
+                             }) {
+            return noexcept(::beman::execution::detail::connect_awaitable(
+                make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>()), ::std::declval<Receiver>()));
+        }
+        return true;
+    }
+#line 56 "include/beman/execution/detail/connect.hpp"
+  public:
+    template <typename Sender, typename Receiver>
+    auto operator()(Sender&& sender, Receiver&& receiver) const noexcept(connect_noexcept<Sender, Receiver>()) {
+        auto new_sender = [&sender, &receiver]() -> decltype(auto) {
+            return make_new_sender(::std::forward<Sender>(sender), ::std::forward<Receiver>(receiver));
+        };
+
+        if constexpr (requires { new_sender().connect(::std::forward<Receiver>(receiver)); }) {
+            using state_type = decltype(new_sender().connect(::std::forward<Receiver>(receiver)));
+            static_assert(::beman::execution::operation_state<state_type>);
+            return new_sender().connect(::std::forward<Receiver>(receiver));
+        } else if constexpr (requires {
+                                 ::beman::execution::detail::connect_awaitable(new_sender(),
+                                                                               ::std::forward<Receiver>(receiver));
+                             }) {
+            return ::beman::execution::detail::connect_awaitable(new_sender(), ::std::forward<Receiver>(receiver));
+        } else {
+            enum bad_sender {};
+            static_assert(::std::same_as<bad_sender, decltype(new_sender())>,
+                          "result from transform_sender has no suitable connect()");
+        }
+    }
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+
+#line 86 "include/beman/execution/detail/connect.hpp"
+export /* --------- */ using connect_t = beman::execution::detail::connect_t;
+
+#line 95 "include/beman/execution/detail/connect.hpp"
+export /* --------- */ inline constexpr connect_t connect{};
+} // namespace beman::execution
+
+#line 16 "include/beman/execution/detail/sender_in.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
+concept sender_in =
+    ::beman::execution::sender<Sender> && ::beman::execution::detail::queryable<Env> &&
+    requires(Sender&& sender, Env&& env) {
+        {
+            ::beman::execution::get_completion_signatures(::std::forward<Sender>(sender), ::std::forward<Env>(env))
+        } -> ::beman::execution::detail::valid_completion_signatures;
+    };
+} // namespace beman::execution
+
+#line 13 "include/beman/execution/detail/connect_result_t.hpp"
+namespace beman::execution {
+
+#line 18 "include/beman/execution/detail/connect_result_t.hpp"
+export /* --------- */ template <typename Sender, typename Receiver>
+using connect_result_t = decltype(::beman::execution::connect(::std::declval<Sender>(), ::std::declval<Receiver>()));
+} // namespace beman::execution
+
+#line 29 "include/beman/execution/detail/stop_when.hpp"
+namespace beman::execution::detail {
+inline constexpr struct stop_when_t {
+    template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
+    struct sender;
+
+    template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
+    auto operator()(Sndr&& sndr, Tok&& tok) const noexcept;
+} stop_when{};
+} // namespace beman::execution::detail
+
+template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
+struct beman::execution::detail::stop_when_t::sender {
+    using sender_concept = ::beman::execution::sender_t;
+
+    stop_when_t               stop_when{};
+    std::remove_cvref_t<Tok>  tok;
+    std::remove_cvref_t<Sndr> sndr;
+
+    template <::beman::execution::receiver Rcvr>
+    struct state {
+        using operation_state_concept = ::beman::execution::operation_state_t;
+        using rcvr_t                  = ::std::remove_cvref_t<Rcvr>;
+        using token1_t                = ::std::remove_cvref_t<Tok>;
+        using token2_t =
+            decltype(::beman::execution::get_stop_token(::beman::execution::get_env(::std::declval<rcvr_t>())));
+
+        struct cb_t {
+            ::beman::execution::inplace_stop_source& source;
+            auto                                     operator()() const noexcept { this->source.request_stop(); }
+        };
+        struct base_state {
+            rcvr_t                                  rcvr;
+            ::beman::execution::inplace_stop_source source{};
+        };
+        struct env {
+            base_state* st;
+            auto        query(const ::beman::execution::get_stop_token_t&) const noexcept {
+                return this->st->source.get_token();
+            }
+            template <typename Q, typename... A>
+                requires requires(const Q& q, A&&... a, const rcvr_t& r) {
+                    q(::beman::execution::get_env(r), ::std::forward<A>(a)...);
+                }
+            auto query(const Q& q, A&&... a) const noexcept {
+                return q(::beman::execution::get_env(this->st->rcvr), ::std::forward<A>(a)...);
+            }
+        };
+
+        struct receiver {
+            using receiver_concept = ::beman::execution::receiver_t;
+            base_state* st;
+
+            auto get_env() const noexcept -> env { return env{this->st}; }
+            template <typename... A>
+            auto set_value(A&&... a) const noexcept -> void {
+                ::beman::execution::set_value(::std::move(this->st->rcvr), ::std::forward<A>(a)...);
+            }
+            template <typename E>
+            auto set_error(E&& e) const noexcept -> void {
+                ::beman::execution::set_error(::std::move(this->st->rcvr), ::std::forward<E>(e));
+            }
+            auto set_stopped() const noexcept -> void { ::beman::execution::set_stopped(::std::move(this->st->rcvr)); }
+        };
+        using inner_state_t =
+            decltype(::beman::execution::connect(::std::declval<Sndr>(), ::std::declval<receiver>()));
+
+        token1_t                                                               tok;
+        base_state                                                             base;
+        std::optional<::beman::execution::stop_callback_for_t<token1_t, cb_t>> cb1;
+        std::optional<::beman::execution::stop_callback_for_t<token2_t, cb_t>> cb2;
+        inner_state_t                                                          inner_state;
+
+        template <::beman::execution::sender S, ::beman::execution::stoppable_token T, ::beman::execution::receiver R>
+        state(S&& s, T&& t, R&& r)
+            : tok(::std::forward<T>(t)),
+              base{::std::forward<R>(r)},
+              inner_state(::beman::execution::connect(::std::forward<S>(s), receiver{&this->base})) {}
+
+        auto start() & noexcept {
+            this->cb1.emplace(this->tok, cb_t{this->base.source});
+            this->cb2.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(this->base.rcvr)),
+                              cb_t{this->base.source});
+            ::beman::execution::start(this->inner_state);
+        }
+    };
+
+    template <typename E>
+    auto get_completion_signatures(const E& e) const noexcept {
+        return ::beman::execution::get_completion_signatures(this->sndr, e);
+    }
+    template <::beman::execution::receiver Rcvr>
+    auto connect(Rcvr&& rcvr) && -> state<Rcvr> {
+        return state<Rcvr>{std::move(this->sndr), ::std::move(this->tok), ::std::forward<Rcvr>(rcvr)};
+    }
+};
+
+template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
+inline auto beman::execution::detail::stop_when_t::operator()(Sndr&& sndr, Tok&& tok) const noexcept {
+    if constexpr (::beman::execution::unstoppable_token<Tok>) {
+        return ::std::forward<Sndr>(sndr);
+    } else {
+        return sender<Sndr, Tok>{*this, ::std::forward<Tok>(tok), ::std::forward<Sndr>(sndr)};
+    }
+}
+#line 16 "include/beman/execution/detail/scope_token.hpp"
+namespace beman::execution::detail {
+struct token_test_env {};
+
+struct token_test_sender {
+    using sender_concept = ::beman::execution::sender_t;
+    template <typename... Env>
+    auto get_completion_signatures(const Env&...) const noexcept {
+        return ::beman::execution::completion_signatures<>{};
+    }
+};
+static_assert(::beman::execution::sender<::beman::execution::detail::token_test_sender>);
+static_assert(::beman::execution::sender_in<::beman::execution::detail::token_test_sender,
+                                            ::beman::execution::detail::token_test_env>);
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ template <typename Token>
+concept scope_token = ::std::copyable<Token> && requires(Token token) {
+    { token.try_associate() } -> ::std::same_as<bool>;
+    { token.disassociate() } noexcept;
+    {
+        token.wrap(::std::declval<::beman::execution::detail::token_test_sender>())
+    } -> ::beman::execution::sender_in<::beman::execution::detail::token_test_env>;
+};
+} // namespace beman::execution
+
+#line 16 "include/beman/execution/detail/completion_signatures_for.hpp"
+namespace beman::execution::detail {
+
+#line 22 "include/beman/execution/detail/completion_signatures_for.hpp"
+struct no_completion_signatures_defined_in_sender {};
+
+#line 29 "include/beman/execution/detail/completion_signatures_for.hpp"
+template <typename Sender, typename Env>
+struct completion_signatures_for_impl {
+    using type = ::beman::execution::detail::no_completion_signatures_defined_in_sender;
+};
+
+#line 39 "include/beman/execution/detail/completion_signatures_for.hpp"
+template <typename Sender, typename Env>
+using completion_signatures_for = ::std::conditional_t<
+    ::std::same_as<beman::execution::detail::no_completion_signatures_defined_in_sender,
+                   typename ::beman::execution::detail::completion_signatures_for_impl<Sender, Env>::type>,
+    typename ::beman::execution::detail::completion_signatures_for_impl<::std::remove_cvref_t<Sender>, Env>::type,
+    typename ::beman::execution::detail::completion_signatures_for_impl<Sender, Env>::type>;
+} // namespace beman::execution::detail
+
+#line 15 "include/beman/execution/detail/completion_signatures_of_t.hpp"
+namespace beman::execution {
+
+#line 20 "include/beman/execution/detail/completion_signatures_of_t.hpp"
+export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
+    requires ::beman::execution::sender_in<Sender, Env>
+using completion_signatures_of_t =
+    ::beman::execution::detail::call_result_t<::beman::execution::get_completion_signatures_t, Sender, Env>;
+} // namespace beman::execution
+
+#line 23 "include/beman/execution/detail/connect_all.hpp"
+namespace beman::execution::detail {
+
+#line 29 "include/beman/execution/detail/connect_all.hpp"
+struct connect_all_t {
+  private:
+    template <typename Fun, typename Tuple, ::std::size_t... I>
+    static auto apply_with_index_helper(::std::index_sequence<I...> seq, Fun&& fun, Tuple&& tuple) noexcept(noexcept(
+        ::std::forward<Fun>(fun)(seq, ::beman::execution::detail::forward_like<Tuple>(::std::get<I>(tuple))...)))
+        -> decltype(auto) {
+        return ::std::forward<Fun>(fun)(seq, ::beman::execution::detail::forward_like<Tuple>(::std::get<I>(tuple))...);
+    }
+    template <typename Fun, typename Tuple>
+    static auto apply_with_index(Fun&& fun, Tuple&& tuple) noexcept(
+        noexcept(apply_with_index_helper(::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>>>{},
+                                         ::std::forward<Fun>(fun),
+                                         ::std::forward<Tuple>(tuple)))) -> decltype(auto) {
+        return apply_with_index_helper(::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>>>{},
+                                       ::std::forward<Fun>(fun),
+                                       ::std::forward<Tuple>(tuple));
+    }
+#line 47 "include/beman/execution/detail/connect_all.hpp"
+    template <::std::size_t Start, typename Fun, typename Tuple, ::std::size_t... I>
+    static auto sub_apply_with_index_helper(::std::index_sequence<I...> seq, Fun&& fun, Tuple&& tuple) noexcept(
+        noexcept(::std::forward<Fun>(fun)(
+            seq, ::beman::execution::detail::forward_like<Tuple>(tuple.template get<I + Start>())...)))
+        -> decltype(auto) {
+        return ::std::forward<Fun>(fun)(
+            seq, ::beman::execution::detail::forward_like<Tuple>(tuple.template get<I + Start>())...);
+    }
+    template <::std::size_t Start, typename Fun, typename Tuple>
+        requires requires { ::std::declval<Tuple>().size(); }
+    static auto sub_apply_with_index(Fun&& fun, Tuple&& tuple) noexcept(noexcept(sub_apply_with_index_helper<Start>(
+        ::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>> - Start>{},
+        ::std::forward<Fun>(fun),
+        ::std::forward<Tuple>(tuple)))) -> decltype(auto) {
+        return sub_apply_with_index_helper<Start>(
+            ::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>> - Start>{},
+            ::std::forward<Fun>(fun),
+            ::std::forward<Tuple>(tuple));
+    }
+    template <::std::size_t Start, typename Fun, typename Tuple>
+        requires(not requires { ::std::declval<Tuple>().size(); })
+    static auto
+    sub_apply_with_index(Fun&& fun,
+                         Tuple&&) noexcept(noexcept(::std::forward<Fun>(fun)(::std::make_index_sequence<0u>{}))) {
+        return ::std::forward<Fun>(fun)(::std::make_index_sequence<0u>{});
+    }
+#line 74 "include/beman/execution/detail/connect_all.hpp"
+    template <typename Sender, typename Receiver>
+    struct connect_helper {
+        ::beman::execution::detail::basic_state<Sender, Receiver>* op;
+
+        template <::std::size_t... J, typename... C>
+        auto operator()(::std::index_sequence<J...>, C&&... c) noexcept(
+            (noexcept(::beman::execution::connect(
+                 ::beman::execution::detail::forward_like<Sender>(c),
+                 ::beman::execution::detail::
+                     basic_receiver<Sender, Receiver, ::std::integral_constant<::std::size_t, J>>{this->op})) &&
+             ... && true)) -> decltype(auto) {
+            return ::beman::execution::detail::product_type{::beman::execution::connect(
+                ::beman::execution::detail::forward_like<Sender>(c),
+                ::beman::execution::detail::
+                    basic_receiver<Sender, Receiver, ::std::integral_constant<::std::size_t, J>>{this->op})...};
+        }
+    };
+
+    static auto use(auto&&...) {}
+
+  public:
+#line 96 "include/beman/execution/detail/connect_all.hpp"
+    template <typename Sender, typename S, typename Receiver, ::std::size_t... I>
+        requires requires(Sender&& s) {
+            s.size();
+            s.template get<0>();
+        }
+    auto operator()(::beman::execution::detail::basic_state<Sender, Receiver>* op,
+                    S&&                                                        sender,
+                    ::std::index_sequence<I...>) const
+        noexcept(noexcept(sub_apply_with_index<2>(connect_helper<Sender, Receiver>{op}, ::std::forward<S>(sender))))
+            -> decltype(auto) {
+        return sub_apply_with_index<2>(connect_helper<Sender, Receiver>{op}, ::std::forward<S>(sender));
+    }
+    template <typename Sender, typename S, typename Receiver, ::std::size_t... I>
+    auto operator()(::beman::execution::detail::basic_state<Sender, Receiver>* op,
+                    S&&                                                        sender,
+                    ::std::index_sequence<I...>) const
+        noexcept(noexcept(apply_with_index(
+            connect_helper<Sender, Receiver>{op},
+            ::beman::execution::detail::get_sender_data(::std::forward<S>(sender)).children))) -> decltype(auto) {
+        return apply_with_index(connect_helper<Sender, Receiver>{op},
+                                ::beman::execution::detail::get_sender_data(::std::forward<S>(sender)).children);
+    }
+};
+
+#line 126 "include/beman/execution/detail/connect_all.hpp"
+export /* --------- */ constexpr connect_all_t connect_all{};
+} // namespace beman::execution::detail
+
+#line 18 "include/beman/execution/detail/error_types_of_t.hpp"
+namespace beman::execution {
+
+#line 23 "include/beman/execution/detail/error_types_of_t.hpp"
+export /* --------- */ template <typename Sender,
+                                 typename Env                         = ::beman::execution::env<>,
+                                 template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
+    requires ::beman::execution::sender_in<Sender, Env>
+using error_types_of_t =
+    ::beman::execution::detail::gather_signatures<::beman::execution::set_error_t,
+                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
+                                                  ::std::type_identity_t,
+                                                  Variant>;
+} // namespace beman::execution
+
+#line 18 "include/beman/execution/detail/sends_stopped.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
+    requires ::beman::execution::sender_in<Sender, Env>
+inline constexpr bool sends_stopped{!::std::same_as<
+    ::beman::execution::detail::type_list<>,
+    ::beman::execution::detail::gather_signatures<::beman::execution::set_stopped_t,
+                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
+                                                  ::beman::execution::detail::type_list,
+                                                  ::beman::execution::detail::type_list>>};
+}
+#line 17 "include/beman/execution/detail/value_types_of_t.hpp"
+namespace beman::execution {
+export /* --------- */ template <typename Sender,
+                                 typename Env                         = ::beman::execution::env<>,
+                                 template <typename...> class Tuple   = ::beman::execution::detail::decayed_tuple,
+                                 template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
+    requires ::beman::execution::sender_in<Sender, Env>
+using value_types_of_t =
+    ::beman::execution::detail::gather_signatures<::beman::execution::set_value_t,
+                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
+                                                  Tuple,
+                                                  Variant>;
+}
+#line 15 "include/beman/execution/detail/connect_all_result.hpp"
+namespace beman::execution::detail {
+
+#line 21 "include/beman/execution/detail/connect_all_result.hpp"
+template <typename Sender, typename Receiver>
+using connect_all_result =
+    ::beman::execution::detail::call_result_t<decltype(::beman::execution::detail::connect_all),
+                                              ::beman::execution::detail::basic_state<Sender, Receiver>*,
+                                              Sender,
+                                              ::beman::execution::detail::indices_for<Sender>>;
+} // namespace beman::execution::detail
+
+#line 28 "include/beman/execution/detail/sync_wait.hpp"
+namespace beman::execution::detail {
+export /* --------- */ struct sync_wait_env {
+    ::beman::execution::run_loop* loop{};
+
+    auto query(::beman::execution::get_scheduler_t) const noexcept { return this->loop->get_scheduler(); }
+    auto query(::beman::execution::get_delegation_scheduler_t) const noexcept { return this->loop->get_scheduler(); }
+};
+
+export /* --------- */ template <::beman::execution::sender_in<::beman::execution::detail::sync_wait_env> Sender>
+using sync_wait_result_type =
+    ::std::optional<::beman::execution::value_types_of_t<Sender,
+                                                         ::beman::execution::detail::sync_wait_env,
+                                                         ::beman::execution::detail::decayed_tuple,
+                                                         ::std::type_identity_t>>;
+
+export /* --------- */ template <typename Sender>
+struct sync_wait_state {
+    ::beman::execution::run_loop loop{};
+    ::std::exception_ptr         error{};
+
+    ::beman::execution::detail::sync_wait_result_type<Sender> result{};
+};
+
+export /* --------- */ template <typename Sender>
+struct sync_wait_receiver {
+    using receiver_concept = ::beman::execution::receiver_t;
+
+    ::beman::execution::detail::sync_wait_state<Sender>* state{};
+
+    template <typename Error>
+    auto set_error(Error&& error) && noexcept -> void {
+        this->state->error = ::beman::execution::detail::as_except_ptr(::std::forward<Error>(error));
+        this->state->loop.finish();
+    }
+    auto set_stopped() && noexcept -> void { this->state->loop.finish(); }
+    template <typename... Args>
+    auto set_value(Args&&... args) && noexcept -> void {
+        try {
+            this->state->result.emplace(::std::forward<Args>(args)...);
+        } catch (...) {
+            this->state->error = ::std::current_exception();
+        }
+        this->state->loop.finish();
+    }
+#line 74 "include/beman/execution/detail/sync_wait.hpp"
+    auto get_env() const noexcept -> ::beman::execution::detail::sync_wait_env {
+        return ::beman::execution::detail::sync_wait_env{&this->state->loop};
+    }
+};
+
+struct sync_wait_t {
+    template <typename Sender>
+    auto apply_sender(Sender&& sender) const {
+        ::beman::execution::detail::sync_wait_state<Sender> state;
+        auto op{::beman::execution::connect(::std::forward<Sender>(sender),
+                                            ::beman::execution::detail::sync_wait_receiver<Sender>{&state})};
+        ::beman::execution::start(op);
+
+        state.loop.run();
+        if (state.error) {
+            ::std::rethrow_exception(state.error);
+        }
+        return ::std::move(state.result);
+    }
+#line 94 "include/beman/execution/detail/sync_wait.hpp"
+    template <::beman::execution::sender_in<::beman::execution::detail::sync_wait_env> Sender>
+        requires requires(Sender&& sender, const sync_wait_t& self) {
+            typename ::beman::execution::detail::sync_wait_result_type<Sender>;
+            {
+                ::beman::execution::apply_sender(
+                    ::beman::execution::detail::get_domain_early(std::forward<Sender>(sender)),
+                    self,
+                    ::std::forward<Sender>(sender))
+            } -> ::std::same_as<::beman::execution::detail::sync_wait_result_type<Sender>>;
+        }
+    auto operator()(Sender&& sender) const {
+        auto domain{::beman::execution::detail::get_domain_early(sender)};
+        return ::beman::execution::apply_sender(domain, *this, ::std::forward<Sender>(sender));
+    }
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using sync_wait_t = ::beman::execution::detail::sync_wait_t;
+
+#line 160 "include/beman/execution/detail/sync_wait.hpp"
+export /* --------- */ inline constexpr ::beman::execution::sync_wait_t sync_wait{};
+} // namespace beman::execution
+
+#line 22 "include/beman/execution/detail/basic_operation.hpp"
+namespace beman::execution::detail {
+
+#line 29 "include/beman/execution/detail/basic_operation.hpp"
+export /* --------- */ template <typename Sender, typename Receiver>
+    requires ::beman::execution::detail::
+
+        valid_specialization<::beman::execution::detail::state_type, std::remove_cvref_t<Sender>, Receiver>
+    struct basic_operation : ::beman::execution::detail::basic_state<Sender, Receiver> {
+
+    friend struct ::beman::execution::start_t;
+    using operation_state_concept = ::beman::execution::operation_state_t;
+    using tag_t                   = ::beman::execution::tag_of_t<Sender>;
+
+    using inner_ops_t = ::beman::execution::detail::connect_all_result<Sender, Receiver>;
+    inner_ops_t inner_ops;
+
+    basic_operation(Sender&& sender, Receiver&& rcvr) noexcept(
+        noexcept(::beman::execution::detail::basic_state<Sender, Receiver>(::std::forward<Sender>(sender),
+                                                                           ::std::move(rcvr))) &&
+        noexcept(::beman::execution::detail::connect_all(this,
+                                                         ::std::forward<Sender>(sender),
+                                                         ::beman::execution::detail::indices_for<Sender>())))
+        : ::beman::execution::detail::basic_state<Sender, Receiver>(::std::forward<Sender>(sender), ::std::move(rcvr)),
+          // NOLINTBEGIN(bugprone-use-after-move,hicpp-invalid-access-moved)
+
+          inner_ops(::beman::execution::detail::connect_all(
+              this, ::std::forward<Sender>(sender), ::beman::execution::detail::indices_for<Sender>())) {}
+    // NOLINTEND(bugprone-use-after-move,hicpp-invalid-access-moved)
+
+  private:
+    auto start() & noexcept -> void {
+        ::std::invoke(
+            [this]<::std::size_t... I>(::std::index_sequence<I...>) {
+                ::beman::execution::detail::impls_for<tag_t>::start(
+                    this->state, this->receiver, this->inner_ops.template get<I>()...);
+            },
+            ::std::make_index_sequence<inner_ops_t::size()>{});
+    }
+};
+template <typename Sender, typename Receiver>
+basic_operation(Sender&&, Receiver&&) -> basic_operation<Sender&&, Receiver>;
+} // namespace beman::execution::detail
+
+#line 17 "include/beman/execution/detail/single_sender_value_type.hpp"
+namespace beman::execution::detail {
+template <typename Sender, typename Env>
+struct single_sender_value_type_helper;
+
+template <typename Sender, typename Env>
+    requires requires {
+        typename ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
+    }
+struct single_sender_value_type_helper<Sender, Env> {
+    using type = ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
+};
+
+template <typename Sender, typename Env>
+    requires ::std::same_as<::std::variant<::std::tuple<>>,
+                            ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>> ||
+             ::std::same_as<::std::variant<>,
+                            ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>>
+struct single_sender_value_type_helper<Sender, Env> {
+    using type = void;
+};
+
+template <typename Sender, typename Env>
+    requires(not requires {
+                typename ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
+            }) &&
+            (!::std::same_as<::std::variant<::std::tuple<>>,
+                             ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>>) &&
+            requires {
+                typename ::beman::execution::
+                    value_types_of_t<Sender, Env, ::beman::execution::detail::decayed_tuple, ::std::type_identity_t>;
+            }
+struct single_sender_value_type_helper<Sender, Env> {
+    using type = ::beman::execution::
+        value_types_of_t<Sender, Env, ::beman::execution::detail::decayed_tuple, ::std::type_identity_t>;
+};
+
+template <typename Sender, typename Env>
+using single_sender_value_type = typename single_sender_value_type_helper<Sender, Env>::type;
+} // namespace beman::execution::detail
+
+#line 23 "include/beman/execution/detail/basic_sender.hpp"
+namespace beman::execution::detail {
+
+#line 29 "include/beman/execution/detail/basic_sender.hpp"
+template <typename Tag, typename Data, typename... Child>
+struct basic_sender : ::beman::execution::detail::product_type<Tag, Data, Child...> {
+    friend struct ::beman::execution::detail::connect_t;
+    friend struct ::beman::execution::get_completion_signatures_t;
+    using sender_concept = ::beman::execution::sender_t;
+    using indices_for    = ::std::index_sequence_for<Child...>;
+
+    auto get_env() const noexcept -> decltype(auto) {
+        auto&& d{this->template get<1>()};
+        return sub_apply<2>(
+            [&d](auto&&... c) { return ::beman::execution::detail::impls_for<Tag>::get_attrs(d, c...); }, *this);
+    }
+#line 42 "include/beman/execution/detail/basic_sender.hpp"
+    template <typename Receiver>
+        requires(!::beman::execution::receiver<Receiver>)
+    auto connect(Receiver receiver) = BEMAN_EXECUTION_DELETE("the passed receiver doesn't model receiver");
+
+  private:
+#if __cpp_explicit_this_parameter < 302110L
+    template <::beman::execution::receiver Receiver>
+    auto connect(Receiver receiver) & noexcept(
+        noexcept(::beman::execution::detail::basic_operation<basic_sender&, Receiver>{*this, ::std::move(receiver)}))
+        -> ::beman::execution::detail::basic_operation<basic_sender&, Receiver> {
+        return {*this, ::std::move(receiver)};
+    }
+    template <::beman::execution::receiver Receiver>
+    auto connect(Receiver receiver) const& noexcept(noexcept(
+        ::beman::execution::detail::basic_operation<const basic_sender&, Receiver>{*this, ::std::move(receiver)}))
+        -> ::beman::execution::detail::basic_operation<const basic_sender&, Receiver> {
+        return {*this, ::std::move(receiver)};
+    }
+    template <::beman::execution::receiver Receiver>
+    auto connect(Receiver receiver) && noexcept(
+        noexcept(::beman::execution::detail::basic_operation<basic_sender, Receiver>{::std::move(*this),
+                                                                                     ::std::move(receiver)}))
+        -> ::beman::execution::detail::basic_operation<basic_sender, Receiver> {
+        return {::std::move(*this), ::std::move(receiver)};
+    }
+#else
+    template <::beman::execution::detail::decays_to<basic_sender> Self, ::beman::execution::receiver Receiver>
+    auto
+    connect(this Self&& self,
+            Receiver receiver) noexcept(noexcept(::beman::execution::detail::basic_operation<basic_sender, Receiver>{
+        ::std::forward<Self>(self), ::std::move(receiver)}))
+        -> ::beman::execution::detail::basic_operation<Self, Receiver> {
+        return {::std::forward<Self>(self), ::std::move(receiver)};
+    }
+#endif
+#if __cpp_explicit_this_parameter < 302110L
+    template <typename Env>
+    auto
+    get_completion_signatures(Env&&) && -> ::beman::execution::detail::completion_signatures_for<basic_sender, Env> {
+        return {};
+    }
+    template <typename Env>
+    auto get_completion_signatures(
+        Env&&) const&& -> ::beman::execution::detail::completion_signatures_for<const basic_sender, Env> {
+        return {};
+    }
+    template <typename Env>
+    auto
+    get_completion_signatures(Env&&) & -> ::beman::execution::detail::completion_signatures_for<basic_sender, Env> {
+        return {};
+    }
+    template <typename Env>
+    auto get_completion_signatures(
+        Env&&) const& -> ::beman::execution::detail::completion_signatures_for<const basic_sender, Env> {
+        return {};
+    }
+#else
+    template <::beman::execution::detail::decays_to<basic_sender> Self, typename Env>
+    auto get_completion_signatures(this Self&&, Env&&) noexcept
+        -> ::beman::execution::detail::completion_signatures_for<Self, Env> {
+        return {};
+    }
+#endif
+};
+} // namespace beman::execution::detail
+
+#line 13 "include/beman/execution/detail/single_sender.hpp"
+namespace beman::execution::detail {
+template <typename Sender, typename Env>
+concept single_sender = ::beman::execution::sender_in<Sender, Env> &&
+                        requires { typename ::beman::execution::detail::single_sender_value_type<Sender, Env>; };
+} // namespace beman::execution::detail
+
+#line 18 "include/beman/execution/detail/make_sender.hpp"
+namespace beman::execution::detail {
+struct make_sender_empty {};
+
+template <typename Tag, typename Data = ::beman::execution::detail::make_sender_empty, typename... Child>
+    requires ::std::semiregular<Tag> && ::beman::execution::detail::movable_value<Data> &&
+             (::beman::execution::sender<Child> && ...)
+constexpr auto make_sender(Tag tag, Data&& data, Child&&... child) {
+    return ::beman::execution::detail::basic_sender<Tag, ::std::decay_t<Data>, ::std::decay_t<Child>...>{
+        tag, ::std::forward<Data>(data), ::std::forward<Child>(child)...};
+}
+} // namespace beman::execution::detail
+
+#line 14 "include/beman/execution/detail/awaitable_sender.hpp"
+namespace beman::execution::detail {
+template <class Sndr, class Promise>
+concept awaitable_sender =
+    ::beman::execution::detail::single_sender<Sndr, ::beman::execution::env_of_t<Promise>> && requires(Promise& prom) {
+        { prom.unhandled_stopped() } -> ::std::convertible_to<::std::coroutine_handle<>>;
+    };
+} // namespace beman::execution::detail
+
+#line 29 "include/beman/execution/detail/sender_awaitable.hpp"
+namespace beman::execution::detail {
+template <class Sndr, class Promise>
+class sender_awaitable {
+    struct unit {};
+    using value_type =
+        ::beman::execution::detail::single_sender_value_type<Sndr, ::beman::execution::env_of_t<Promise>>;
+    using result_type  = ::std::conditional_t<::std::is_void_v<value_type>, unit, value_type>;
+    using variant_type = ::std::variant<::std::monostate, result_type, ::std::exception_ptr>;
+    using data_type    = ::std::tuple<variant_type, ::std::atomic<bool>, ::std::coroutine_handle<Promise>>;
+
+    struct awaitable_receiver {
+        using receiver_concept = ::beman::execution::receiver_t;
+
+        void resume() {
+            if (::std::get<1>(*result_ptr_).exchange(true, std::memory_order_acq_rel)) {
+                ::std::get<2>(*result_ptr_).resume();
+            }
+        }
+#line 48 "include/beman/execution/detail/sender_awaitable.hpp"
+        template <class... Args>
+            requires ::std::constructible_from<result_type, Args...>
+        void set_value(Args&&... args) && noexcept {
+            try {
+                ::std::get<0>(*result_ptr_).template emplace<1>(::std::forward<Args>(args)...);
+            } catch (...) {
+                ::std::get<0>(*result_ptr_).template emplace<2>(::std::current_exception());
+            }
+            this->resume();
+        }
+        template <class Error>
+        void set_error(Error&& error) && noexcept {
+            ::std::get<0>(*result_ptr_)
+                .template emplace<2>(::beman::execution::detail::as_except_ptr(::std::forward<Error>(error)));
+            this->resume();
+        }
+#line 65 "include/beman/execution/detail/sender_awaitable.hpp"
+        void set_stopped() && noexcept {
+            if (::std::get<1>(*result_ptr_).exchange(true, ::std::memory_order_acq_rel)) {
+                static_cast<::std::coroutine_handle<>>(::std::get<2>(*result_ptr_).promise().unhandled_stopped())
+                    .resume();
+            }
+        }
+#line 72 "include/beman/execution/detail/sender_awaitable.hpp"
+        auto get_env() const noexcept {
+            return ::beman::execution::detail::fwd_env{
+                ::beman::execution::get_env(::std::get<2>(*result_ptr_).promise())};
+        }
+#line 77 "include/beman/execution/detail/sender_awaitable.hpp"
+        data_type* result_ptr_;
+    };
+    using op_state_type = ::beman::execution::connect_result_t<Sndr, awaitable_receiver>;
+
+    data_type     result{};
+    op_state_type state;
+
+  public:
+    sender_awaitable(Sndr&& sndr, Promise& p)
+        : result{::std::monostate{}, false, ::std::coroutine_handle<Promise>::from_promise(p)},
+          state{::beman::execution::connect(::std::forward<Sndr>(sndr),
+                                            sender_awaitable::awaitable_receiver{::std::addressof(result)})} {}
+
+    static constexpr bool     await_ready() noexcept { return false; }
+    ::std::coroutine_handle<> await_suspend(::std::coroutine_handle<Promise> handle) noexcept {
+        ::beman::execution::start(state);
+        if (::std::get<1>(this->result).exchange(true, std::memory_order_acq_rel)) {
+            if (::std::holds_alternative<::std::monostate>(::std::get<0>(this->result))) {
+                return ::std::get<2>(this->result).promise().unhandled_stopped();
+            }
+            return ::std::move(handle);
+        }
+        return ::std::noop_coroutine();
+    }
+    value_type await_resume() {
+        if (::std::holds_alternative<::std::exception_ptr>(::std::get<0>(result))) {
+            ::std::rethrow_exception(::std::get<::std::exception_ptr>(::std::get<0>(result)));
+        }
+        if constexpr (::std::is_void_v<value_type>) {
+            return;
+        } else {
+            return ::std::get<value_type>(std::move(::std::get<0>(result)));
+        }
+    }
+};
+} // namespace beman::execution::detail
+
+#line 33 "include/beman/execution/detail/bulk.hpp"
+namespace beman::execution::detail {
+
+struct bulk_t : ::beman::execution::sender_adaptor_closure<bulk_t> {
+
+    template <class Shape, class f>
+        requires(std::is_integral_v<Shape> && ::beman::execution::detail::movable_value<f>)
+    auto operator()(Shape&& shape, f&& fun) const {
+        return beman::execution::detail::sender_adaptor{*this, std::forward<Shape>(shape), std::forward<f>(fun)};
+    }
+#line 43 "include/beman/execution/detail/bulk.hpp"
+    template <class Sender, class Shape, class f>
+        requires(::beman::execution::sender<Sender> && std::is_integral_v<Shape> &&
+                 ::beman::execution::detail::movable_value<f>)
+    auto operator()(Sender&& sndr, Shape&& shape, f&& fun) const {
+
+        auto domain{::beman::execution::detail::get_domain_early(sndr)};
+
+        return ::beman::execution::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(
+                *this, ::beman::execution::detail::product_type<Shape, f>{shape, fun}, std::forward<Sender>(sndr)));
+    }
+};
+
+template <>
+struct impls_for<bulk_t> : ::beman::execution::detail::default_impls {
+
+    static constexpr auto complete = []<class Index, class Shape, class Fun, class Rcvr, class Tag, class... Args>(
+                                         Index,
+                                         ::beman::execution::detail::product_type<Shape, Fun>& state,
+                                         Rcvr&                                                 rcvr,
+                                         Tag,
+                                         Args&&... args) noexcept -> void
+        requires(!::std::same_as<Tag, set_value_t> || std::is_invocable_v<Fun, Shape, Args...>)
+    {
+        if constexpr (std::same_as<Tag, set_value_t>) {
+            auto& [shape, f] = state;
+
+            using s_type = std::remove_cvref_t<decltype(shape)>;
+
+            constexpr bool nothrow = noexcept(f(s_type(shape), args...));
+
+            try {
+                [&]() noexcept(nothrow) {
+                    for (decltype(s_type(shape)) i = 0; i < shape; i++) {
+                        f(s_type(i), args...);
+                    }
+                    Tag()(std::move(rcvr), std::forward<Args>(args)...);
+                }();
+
+            } catch (...) {
+                if constexpr (not nothrow) {
+                    ::beman::execution::set_error(std::move(rcvr), std::current_exception());
+                }
+            }
+        } else {
+            Tag()(std::move(rcvr), std::forward<Args>(args)...);
+        }
+    };
+};
+
+template <typename, typename, typename>
+struct fixed_completions_helper;
+
+template <typename F, typename Shape, typename... Args>
+struct fixed_completions_helper<F, Shape, completion_signatures<Args...>> {
+
+    template <typename, typename>
+    struct may_throw;
+    template <typename XF, typename Tag, typename... XArgs>
+    struct may_throw<XF, Tag(XArgs...)> {
+        static constexpr bool value =
+            std::same_as<Tag, ::beman::execution::set_value_t> && !::std::is_nothrow_invocable<XF, Shape, XArgs...>();
+    };
+    template <typename XF, typename... Sigs>
+    struct may_throw<XF, completion_signatures<Sigs...>> {
+        static constexpr bool value = (false || ... || may_throw<XF, Sigs>::value);
+    };
+
+    using type = std::conditional_t<!may_throw<F, Args...>::value,
+                                    completion_signatures<Args...>,
+                                    completion_signatures<Args..., set_error_t(std::exception_ptr)>>;
+};
+
+template <typename F, typename Shape, typename Completions>
+using fixed_completions = typename fixed_completions_helper<F, Shape, Completions>::type;
+
+template <class Shape, class F, class Sender, class Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::
+        basic_sender<::beman::execution::detail::bulk_t, ::beman::execution::detail::product_type<Shape, F>, Sender>,
+    Env> {
+
+    using completions = decltype(get_completion_signatures(std::declval<Sender>(), std::declval<Env>()));
+    using type        = ::beman::execution::detail::meta::unique<
+               ::beman::execution::detail::meta::combine<fixed_completions<F, Shape, completions>>>;
+};
+
+} // namespace beman::execution::detail
+
+#line 135 "include/beman/execution/detail/bulk.hpp"
+namespace beman::execution {
+
+export /* --------- */ using bulk_t = ::beman::execution::detail::bulk_t;
+export /* --------- */ inline constexpr ::beman::execution::bulk_t bulk{};
+
+} // namespace beman::execution
+
+#line 32 "include/beman/execution/detail/into_variant.hpp"
+namespace beman::execution::detail {
+export /* --------- */ struct into_variant_t {
+    template <::beman::execution::sender Sender>
+    auto operator()(Sender&& sender) const {
+        auto domain{::beman::execution::detail::get_domain_early(sender)};
+        (void)domain;
+        return ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender));
+
+#line 43 "include/beman/execution/detail/into_variant.hpp"
+    }
+};
+
+template <>
+struct impls_for<::beman::execution::detail::into_variant_t> : ::beman::execution::detail::default_impls {
+    static constexpr auto get_state = []<typename Sender, typename Receiver>(Sender&&, Receiver&&) noexcept
+        -> ::std::type_identity<::beman::execution::value_types_of_t<::beman::execution::detail::child_type<Sender>,
+                                                                     ::beman::execution::env_of_t<Receiver>>> {
+        return {};
+    };
+    static constexpr auto complete = []<typename State, typename Tag, typename... Args>(
+                                         auto, State, auto& receiver, Tag, Args&&... args) noexcept -> void {
+        if constexpr (::std::same_as<Tag, ::beman::execution::set_value_t>) {
+            using variant_type = typename State::type;
+            using tuple_type   = ::beman::execution::detail::decayed_tuple<Args...>;
+            try {
+                if constexpr (sizeof...(Args) == 0u)
+                    ::beman::execution::set_value(::std::move(receiver));
+                else
+                    ::beman::execution::set_value(::std::move(receiver),
+                                                  variant_type(tuple_type{::std::forward<Args>(args)...}));
+            } catch (...) {
+                ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+            }
+#line 68 "include/beman/execution/detail/into_variant.hpp"
+        } else {
+            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
+        }
+    };
+};
+
+template <typename Sender, typename State, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::into_variant_t, State, Sender>,
+    Env> {
+    using variant_type = ::beman::execution::value_types_of_t<Sender, Env>;
+    using value_types =
+        ::std::conditional_t<::std::same_as<variant_type, ::beman::execution::detail::empty_variant>,
+                             ::beman::execution::completion_signatures<>,
+                             ::beman::execution::completion_signatures<::beman::execution::set_value_t(variant_type)>>;
+    template <typename... E>
+    using make_error_types = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
+
+    using error_types = ::beman::execution::error_types_of_t<Sender, Env, make_error_types>;
+    using stopped_types =
+        ::std::conditional_t<::beman::execution::sends_stopped<Sender, Env>,
+                             ::beman::execution::completion_signatures<::beman::execution::set_stopped_t()>,
+                             ::beman::execution::completion_signatures<>>;
+    using type = ::beman::execution::detail::meta::
+        combine<value_types, ::beman::execution::detail::meta::combine<error_types, stopped_types>>;
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using into_variant_t = ::beman::execution::detail::into_variant_t;
+export /* --------- */ inline constexpr into_variant_t into_variant{};
+} // namespace beman::execution
+
+#line 25 "include/beman/execution/detail/just.hpp"
+namespace beman::execution::detail {
+template <typename Completion, typename... T>
+concept just_size = (!::std::same_as<Completion, ::beman::execution::set_error_t> or 1u == sizeof...(T)) &&
+                    (!::std::same_as<Completion, ::beman::execution::set_stopped_t> or 0u == sizeof...(T));
+template <typename Completion>
+struct just_t {
+    template <typename... T>
+        requires ::beman::execution::detail::just_size<Completion, T...> &&
+                 (::beman::execution::detail::movable_value<T> && ...)
+    auto operator()(T&&... arg) const {
+        return ::beman::execution::detail::make_sender(
+            *this, ::beman::execution::detail::product_type{::std::forward<T>(arg)...});
+    }
+    template <::beman::execution::sender Sender>
+    static auto affine_on(Sender&& sndr, const auto&) noexcept {
+        return ::std::forward<Sender>(sndr);
+    }
+};
+
+template <typename Completion, typename... T, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<just_t<Completion>, ::beman::execution::detail::product_type<T...>>,
+    Env> {
+    using type = ::beman::execution::completion_signatures<Completion(T...)>;
+};
+
+template <typename Completion>
+struct impls_for<just_t<Completion>> : ::beman::execution::detail::default_impls {
+    static constexpr auto start = []<typename State>(State& state, auto& receiver) noexcept -> void {
+        [&state, &receiver]<::std::size_t... I>(::std::index_sequence<I...>) {
+            Completion()(::std::move(receiver), ::std::move(state.template get<I>())...);
+        }(::std::make_index_sequence<State::size()>{});
+    };
+};
+} // namespace beman::execution::detail
+
+#line 63 "include/beman/execution/detail/just.hpp"
+namespace beman::execution {
+export /* --------- */ using just_t         = ::beman::execution::detail::just_t<::beman::execution::set_value_t>;
+export /* --------- */ using just_error_t   = ::beman::execution::detail::just_t<::beman::execution::set_error_t>;
+export /* --------- */ using just_stopped_t = ::beman::execution::detail::just_t<::beman::execution::set_stopped_t>;
+
+#line 117 "include/beman/execution/detail/just.hpp"
+export /* --------- */ inline constexpr ::beman::execution::just_t just{};
+
+#line 175 "include/beman/execution/detail/just.hpp"
+export /* --------- */ inline constexpr ::beman::execution::just_error_t just_error{};
+
+#line 229 "include/beman/execution/detail/just.hpp"
+export /* --------- */ inline constexpr ::beman::execution::just_stopped_t just_stopped{};
+} // namespace beman::execution
+
+#line 49 "include/beman/execution/detail/let.hpp"
+namespace beman::execution::detail {
+template <typename Completion>
+struct let_t {
+    template <::beman::execution::detail::movable_value Fun>
+    auto operator()(Fun&& fun) const {
+        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Fun>(fun)};
+    }
+    template <::beman::execution::sender Sender, ::beman::execution::detail::movable_value Fun>
+    auto operator()(Sender&& sender, Fun&& fun) const {
+        auto domain(::beman::execution::detail::get_domain_early(sender));
+        return ::beman::execution::detail::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(*this, ::std::forward<Fun>(fun), std::forward<Sender>(sender)));
+    }
+#line 64 "include/beman/execution/detail/let.hpp"
+    template <typename Sender>
+    static auto env(Sender&& sender) {
+        if constexpr (requires {
+                          ::beman::execution::detail::sched_env(
+                              ::beman::execution::get_completion_scheduler<Completion>(
+                                  ::beman::execution::get_env(sender)));
+                      })
+            return ::beman::execution::detail::sched_env(
+                ::beman::execution::get_completion_scheduler<Completion>(::beman::execution::get_env(sender)));
+        else if constexpr (requires {
+                               ::beman::execution::detail::make_env(
+                                   ::beman::execution::get_domain,
+                                   ::beman::execution::get_domain(::beman::execution::get_env(sender)));
+                           })
+            return ::beman::execution::detail::make_env(
+                ::beman::execution::get_domain, ::beman::execution::get_domain(::beman::execution::get_env(sender)));
+        else
+            return ::beman::execution::env<>{};
+    }
+    template <typename Sender, typename Env>
+    static auto join_env(Sender&& sender, Env&& e) -> decltype(auto) {
+        return ::beman::execution::detail::join_env(env(sender), ::beman::execution::detail::fwd_env(e));
+    }
+};
+
+template <typename Completion>
+struct impls_for<::beman::execution::detail::let_t<Completion>> : ::beman::execution::detail::default_impls {
+
+    template <typename Receiver, typename Env>
+    struct let_receiver {
+        using receiver_concept = ::beman::execution::receiver_t;
+
+        Receiver& receiver;
+        Env       env;
+
+        auto get_env() const noexcept -> decltype(auto) {
+            return ::beman::execution::detail::join_env(
+                this->env, ::beman::execution::detail::fwd_env(::beman::execution::get_env(this->receiver)));
+        }
+        template <typename Error>
+        auto set_error(Error&& error) && noexcept -> void {
+            ::beman::execution::set_error(::std::move(this->receiver), ::std::forward<Error>(error));
+        }
+        auto set_stopped() && noexcept -> void { ::beman::execution::set_stopped(::std::move(this->receiver)); }
+        template <typename... Args>
+        auto set_value(Args&&... args) && noexcept -> void {
+            ::beman::execution::set_value(::std::move(this->receiver), ::std::forward<Args>(args)...);
+        }
+    };
+
+    template <typename>
+    struct filter_pred : ::std::false_type {};
+    template <typename... A>
+    struct filter_pred<Completion(A...)> : ::std::true_type {};
+    template <typename>
+    struct to_tuple;
+    template <typename C, typename... A>
+    struct to_tuple<C(A...)> {
+        using type = ::beman::execution::detail::decayed_tuple<A...>;
+    };
+    template <typename T>
+    using to_tuple_t = typename to_tuple<T>::type;
+    template <typename Fun, typename Receiver, typename Env>
+    struct to_state {
+        template <typename Tuple>
+        using trans =
+            decltype(::beman::execution::connect(::std::apply(::std::declval<Fun>(), ::std::declval<Tuple>()),
+                                                 ::std::declval<let_receiver<Receiver, Env>>()));
+    };
+
+    static constexpr auto get_state{[]<typename Sender, typename Receiver>(Sender&& sender, Receiver&& receiver) {
+        auto& fun{sender.template get<1>()};
+        auto& child{sender.template get<2>()};
+
+        using fun_t   = ::std::remove_cvref_t<decltype(fun)>;
+        using child_t = ::std::remove_cvref_t<decltype(child)>;
+        using env_t   = decltype(::beman::execution::detail::let_t<Completion>::env(child));
+        using sigs_t = ::beman::execution::completion_signatures_of_t<child_t, ::beman::execution::env_of_t<Receiver>>;
+        using comp_sigs_t = ::beman::execution::detail::meta::filter<filter_pred, sigs_t>;
+        using type_list_t = ::beman::execution::detail::meta::to<::std::variant, comp_sigs_t>;
+        using tuples_t    = ::beman::execution::detail::meta::transform<to_tuple_t, type_list_t>;
+        using unique_t    = ::beman::execution::detail::meta::unique<tuples_t>;
+        using args_t      = ::beman::execution::detail::meta::prepend<std::monostate, unique_t>;
+        using ops_t       = ::beman::execution::detail::meta::prepend<
+                  ::std::monostate,
+                  ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::transform<
+                      to_state<fun_t, ::std::remove_cvref_t<Receiver>, env_t>::template trans,
+                      tuples_t>>>;
+
+        struct state_t {
+            fun_t  fun;
+            env_t  env;
+            args_t args;
+            ops_t  ops2;
+        };
+        return state_t{beman::execution::detail::allocator_aware_move(
+                           ::beman::execution::detail::forward_like<Sender>(fun), receiver),
+                       ::beman::execution::detail::let_t<Completion>::env(child),
+                       {},
+                       {}};
+    }};
+    template <typename Receiver, typename... Args>
+    static auto
+    let_bind(auto& state, Receiver& receiver, Args&&... args) noexcept(noexcept(::beman::execution::connect(
+        ::std::apply(::std::move(state.fun),
+                     ::std::move(state.args.template emplace<::beman::execution::detail::decayed_tuple<Args...>>(
+                         ::std::forward<Args>(args)...))),
+        let_receiver<Receiver, decltype(state.env)>{receiver, state.env}))) {
+        using args_t = ::beman::execution::detail::decayed_tuple<Args...>;
+        auto mkop{[&] {
+            return ::beman::execution::connect(
+                ::std::apply(::std::move(state.fun),
+                             ::std::move(state.args.template emplace<args_t>(::std::forward<Args>(args)...))),
+                let_receiver<Receiver, decltype(state.env)>{receiver, state.env});
+        }};
+        ::beman::execution::start(
+            state.ops2.template emplace<decltype(mkop())>(beman::execution::detail::emplace_from{mkop}));
+    }
+    static constexpr auto complete{
+        []<class Tag, class... Args>(auto, auto& state, auto& receiver, Tag, Args&&... args) {
+            if constexpr (::std::same_as<Tag, Completion>) {
+                try {
+                    let_bind(state, receiver, ::std::forward<Args>(args)...);
+                } catch (...) {
+                    if constexpr (not noexcept(let_bind(state, receiver, ::std::forward<Args>(args)...)))
+                        ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+                }
+            } else {
+                Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
+            }
+        }};
+};
+
+template <typename Completion, typename Fun, typename Sender, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::let_t<Completion>, Fun, Sender>,
+    Env> {
+    template <typename>
+    struct other_completion : ::std::true_type {};
+    template <typename... A>
+    struct other_completion<Completion(A...)> : ::std::false_type {};
+    template <typename>
+    struct matching_completion : ::std::false_type {};
+    template <typename... A>
+    struct matching_completion<Completion(A...)> : ::std::true_type {};
+
+    template <typename>
+    struct apply_decayed;
+    template <typename C, typename... A>
+    struct apply_decayed<C(A...)> {
+        using sender_type = ::beman::execution::detail::call_result_t<Fun, ::std::decay_t<A>...>;
+    };
+    template <typename>
+    struct get_completions;
+    template <template <typename...> class L, typename... C>
+    struct get_completions<L<C...>> {
+        using type = ::beman::execution::detail::meta::unique<
+            ::beman::execution::detail::meta::combine<decltype(::beman::execution::get_completion_signatures(
+                std::declval<typename apply_decayed<C>::sender_type>(), std::declval<Env>()))...>>;
+    };
+
+    using upstream_env = decltype(::beman::execution::detail::let_t<Completion>::join_env(::std::declval<Sender>(),
+                                                                                          ::std::declval<Env>()));
+    using upstream_completions = decltype(::beman::execution::get_completion_signatures(
+        ::std::declval<Sender>(), ::std::declval<upstream_env>()));
+    using other_completions    = ::beman::execution::detail::meta::filter<other_completion, upstream_completions>;
+    using matching_completions = ::beman::execution::detail::meta::filter<matching_completion, upstream_completions>;
+    using type = ::beman::execution::detail::meta::combine<typename get_completions<matching_completions>::type,
+                                                           other_completions>;
+};
+} // namespace beman::execution::detail
+
+#line 238 "include/beman/execution/detail/let.hpp"
+namespace beman::execution {
+export /* --------- */ using let_error_t   = ::beman::execution::detail::let_t<::beman::execution::set_error_t>;
+export /* --------- */ using let_stopped_t = ::beman::execution::detail::let_t<::beman::execution::set_stopped_t>;
+export /* --------- */ using let_value_t   = ::beman::execution::detail::let_t<::beman::execution::set_value_t>;
+
+export /* --------- */ inline constexpr ::beman::execution::let_error_t   let_error{};
+export /* --------- */ inline constexpr ::beman::execution::let_stopped_t let_stopped{};
+export /* --------- */ inline constexpr ::beman::execution::let_value_t   let_value{};
+} // namespace beman::execution
+
+#line 22 "include/beman/execution/detail/read_env.hpp"
+namespace beman::execution::detail {
+struct read_env_t {
+    auto operator()(auto&& query) const { return ::beman::execution::detail::make_sender(*this, query); }
+    template <::beman::execution::sender Sender>
+    static auto affine_on(Sender&& sndr, const auto&) noexcept {
+        return ::std::forward<Sender>(sndr);
+    }
+};
+
+template <>
+struct impls_for<::beman::execution::detail::read_env_t> : ::beman::execution::detail::default_impls {
+    static constexpr auto start = [](auto query, auto& receiver) noexcept -> void {
+        try {
+            auto env{::beman::execution::get_env(receiver)};
+            ::beman::execution::set_value(::std::move(receiver), query(env));
+        } catch (...) {
+            ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+        }
+    };
+};
+
+template <typename Query, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::read_env_t, Query>,
+    Env> {
+    using set_value_type =
+        ::beman::execution::set_value_t(decltype(::std::declval<Query>()(::std::as_const(::std::declval<Env>()))));
+    using set_error_type = ::beman::execution::set_error_t(::std::exception_ptr);
+    using type           = ::std::conditional_t<noexcept(::std::declval<Query>()(::std::declval<const Env&>())),
+                                                ::beman::execution::completion_signatures<set_value_type>,
+                                                ::beman::execution::completion_signatures<set_value_type, set_error_type>>;
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using read_env_t = beman::execution::detail::read_env_t;
+export /* --------- */ inline constexpr read_env_t read_env{};
+} // namespace beman::execution
+
+#line 47 "include/beman/execution/detail/schedule_from.hpp"
+namespace beman::execution::detail {
+struct schedule_from_t {
+    template <::beman::execution::scheduler Scheduler, ::beman::execution::sender Sender>
+    auto operator()(Scheduler&& scheduler, Sender&& sender) const {
+        auto domain{::beman::execution::detail::query_with_default(
+            ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{})};
+        return ::beman::execution::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(
+                *this, ::std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
+    }
+};
+
+template <>
+struct impls_for<::beman::execution::detail::schedule_from_t> : ::beman::execution::detail::default_impls {
+    template <typename State>
+    struct upstream_receiver {
+        using receiver_concept = ::beman::execution::receiver_t;
+        State* state;
+
+        auto set_value() && noexcept -> void {
+            try {
+                ::std::visit(
+                    [this]<typename Tuple>(Tuple& result) noexcept -> void {
+                        if constexpr (!::std::same_as<::std::monostate, Tuple>) {
+                            ::std::apply(
+                                [this](auto&& tag, auto&&... args) {
+                                    tag(::std::move(this->state->receiver), ::std::move(args)...);
+                                },
+                                result);
+                        }
+                    },
+                    state->async_result);
+            } catch (...) {
+                ::beman::execution::set_error(::std::move(state->receiver), ::std::current_exception());
+            }
+        }
+#line 85 "include/beman/execution/detail/schedule_from.hpp"
+        template <typename Error>
+        auto set_error(Error&& err) && noexcept -> void {
+            ::beman::execution::set_error(std::move(state->receiver), std::forward<Error>(err));
+        }
+#line 90 "include/beman/execution/detail/schedule_from.hpp"
+        auto set_stopped() && noexcept -> void { ::beman::execution::set_stopped(std::move(state->receiver)); }
+
+        auto get_env() const noexcept -> decltype(auto) {
+            return ::beman::execution::detail::fwd_env(::beman::execution::get_env(state->receiver));
+        }
+    };
+    template <typename Receiver, typename Variant>
+    struct state_base {
+        Receiver receiver;
+        Variant  async_result{};
+    };
+    template <typename Receiver, typename Scheduler, typename Variant>
+    struct state_type : state_base<Receiver, Variant> {
+        using receiver_t = upstream_receiver<state_base<Receiver, Variant>>;
+        using operation_t =
+            ::beman::execution::connect_result_t<::beman::execution::schedule_result_t<Scheduler>, receiver_t>;
+        operation_t op_state;
+
+        static constexpr bool nothrow() {
+            return noexcept(::beman::execution::connect(::beman::execution::schedule(::std::declval<Scheduler>()),
+                                                        receiver_t{nullptr}));
+        }
+        explicit state_type(Scheduler& sch, Receiver& rcvr) noexcept(nothrow())
+            : state_base<Receiver, Variant>{rcvr},
+              op_state(::beman::execution::connect(::beman::execution::schedule(sch), receiver_t{this})) {}
+    };
+
+    static constexpr auto get_attrs{[](const auto& data, const auto& child) noexcept -> decltype(auto) {
+        return ::beman::execution::detail::join_env(
+            ::beman::execution::detail::sched_attrs(data),
+            ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
+    }};
+    static constexpr auto get_state{
+        []<typename Sender, typename Receiver>(Sender&& sender, Receiver& receiver)
+            requires ::beman::execution::sender_in<::beman::execution::detail::child_type<Sender>,
+                                                   ::beman::execution::env_of_t<Receiver>>
+        {
+            auto sch{sender.template get<1>()};
+
+            using sched_t   = ::std::remove_cvref_t<decltype(sch)>;
+            using variant_t = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
+                ::std::monostate,
+                ::beman::execution::detail::meta::transform<
+                    ::beman::execution::detail::as_tuple_t,
+                    ::beman::execution::detail::meta::to<::std::variant,
+                                                         ::beman::execution::detail::meta::combine<
+                                                             ::beman::execution::completion_signatures_of_t<
+                                                                 ::beman::execution::detail::child_type<Sender>,
+                                                                 ::beman::execution::env_of_t<Receiver>>,
+
+                                                             ::beman::execution::completion_signatures<
+                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
+                                                                 ::beman::execution::set_stopped_t()>>>>>>;
+
+            return state_type<Receiver, sched_t, variant_t>(sch, receiver);
+        }};
+    static constexpr auto complete{
+        []<typename Tag, typename... Args>(auto, auto& state, auto& receiver, Tag, Args&&... args) noexcept -> void {
+            using result_t         = ::beman::execution::detail::decayed_tuple<Tag, Args...>;
+            constexpr bool nothrow = ::std::is_nothrow_constructible_v<result_t, Tag, Args...>;
+
+            try {
+                [&]() noexcept(nothrow) {
+                    state.async_result.template emplace<result_t>(Tag(), std::forward<Args>(args)...);
+                }();
+            } catch (...) {
+                if constexpr (not nothrow)
+                    ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+            }
+#line 160 "include/beman/execution/detail/schedule_from.hpp"
+            if (state.async_result.index() == 0)
+                return;
+
+            ::beman::execution::start(state.op_state);
+        }};
+};
+
+template <typename Scheduler, typename Sender, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::schedule_from_t, Scheduler, Sender>,
+    Env> {
+    using scheduler_sender = decltype(::beman::execution::schedule(::std::declval<Scheduler>()));
+    template <typename... E>
+    using as_set_error = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
+    using type         = ::beman::execution::detail::meta::combine<
+                decltype(::beman::execution::get_completion_signatures(::std::declval<Sender>(), ::std::declval<Env>())),
+                ::beman::execution::error_types_of_t<scheduler_sender, Env, as_set_error>,
+                ::beman::execution::completion_signatures<::beman::execution::set_error_t(::std::exception_ptr)>>;
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using schedule_from_t = beman::execution::detail::schedule_from_t;
+export /* --------- */ inline constexpr ::beman::execution::schedule_from_t schedule_from{};
+} // namespace beman::execution
+
+#line 40 "include/beman/execution/detail/split.hpp"
+namespace beman::execution::detail {
+
+struct split_impl_t {};
+template <>
+struct impls_for<split_impl_t> : ::beman::execution::detail::default_impls {
+
+    template <class Sndr>
+    struct shared_state;
+
+    struct split_env {
+        ::beman::execution::inplace_stop_source* stop_source;
+
+        ::beman::execution::inplace_stop_token query(::beman::execution::get_stop_token_t) const noexcept {
+            return stop_source->get_token();
+        }
+    };
+
+    struct local_state_base {
+        local_state_base* next{nullptr};
+        virtual auto      notify() noexcept -> void = 0;
+
+        local_state_base() noexcept                                  = default;
+        local_state_base(const local_state_base&)                    = delete;
+        local_state_base(local_state_base&&)                         = delete;
+        auto operator=(const local_state_base&) -> local_state_base& = delete;
+        auto operator=(local_state_base&&) -> local_state_base&      = delete;
+
+      protected:
+        ~local_state_base() = default;
+    };
+
+    template <class Sndr>
+    struct split_receiver {
+        using receiver_concept = ::beman::execution::receiver_t;
+
+        explicit split_receiver(shared_state<Sndr>* state) noexcept : sh_state(state) {
+            if (sh_state) {
+                sh_state->inc_ref();
+            }
+        }
+#line 81 "include/beman/execution/detail/split.hpp"
+        ~split_receiver() noexcept {
+            if (sh_state) {
+                sh_state->dec_ref();
+            }
+        }
+#line 87 "include/beman/execution/detail/split.hpp"
+        split_receiver(split_receiver&& other) noexcept : sh_state(::std::exchange(other.sh_state, nullptr)) {}
+        split_receiver& operator=(split_receiver&& other) noexcept {
+            sh_state = ::std::exchange(other.sh_state, nullptr);
+            return *this;
+        }
+#line 93 "include/beman/execution/detail/split.hpp"
+        split_receiver(const split_receiver&)            = delete;
+        split_receiver& operator=(const split_receiver&) = delete;
+
+        template <class Tag, class... Args>
+        void complete(Tag, Args&&... args) noexcept {
+            using tuple_t = ::beman::execution::detail::decayed_tuple<Tag, Args...>;
+            try {
+                sh_state->result.template emplace<tuple_t>(Tag(), ::std::forward<Args>(args)...);
+            } catch (...) {
+                using tuple_err = ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>;
+                sh_state->result.template emplace<tuple_err>(::beman::execution::set_error,
+                                                             ::std::current_exception());
+            }
+            sh_state->notify();
+        }
+#line 109 "include/beman/execution/detail/split.hpp"
+        template <class... Args>
+        void set_value(Args&&... args) && noexcept {
+            complete(::beman::execution::set_value, ::std::forward<Args>(args)...);
+        }
+#line 114 "include/beman/execution/detail/split.hpp"
+        template <class Error>
+        void set_error(Error&& err) && noexcept {
+            complete(::beman::execution::set_error, ::std::forward<Error>(err));
+        }
+#line 119 "include/beman/execution/detail/split.hpp"
+        void set_stopped() && noexcept { complete(::beman::execution::set_stopped); }
+
+        split_env get_env() const noexcept { return split_env{&sh_state->stop_src}; }
+
+        shared_state<Sndr>* sh_state;
+    };
+
+#line 127 "include/beman/execution/detail/split.hpp"
+    template <class Sndr>
+    struct shared_state {
+        template <class... Args>
+        using value_tuple = ::std::tuple<::beman::execution::set_value_t, ::std::decay_t<Args>...>;
+
+        template <class... Args>
+        using error_tuples = ::std::variant<::std::tuple<::beman::execution::set_error_t, ::std::decay_t<Args>>...>;
+
+        using variant_type = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::combine<
+            ::std::variant<::std::monostate>,
+            ::std::variant<::std::tuple<::beman::execution::set_stopped_t>>,
+            ::std::variant<::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>>,
+            ::beman::execution::error_types_of_t<Sndr, split_env, error_tuples>,
+            ::beman::execution::value_types_of_t<Sndr, split_env, value_tuple>>>;
+
+        using state_list_type = ::beman::execution::detail::atomic_intrusive_stack<&local_state_base::next>;
+
+        using child_operation_state = ::beman::execution::connect_result_t<Sndr, split_receiver<Sndr>>;
+
+        explicit shared_state(Sndr&& sndr) {
+            try {
+                op_state.emplace(::beman::execution::detail::emplace_from{[&] {
+                    return ::beman::execution::connect(::std::forward<Sndr>(sndr), split_receiver<Sndr>{this});
+                }});
+            } catch (...) {
+                using error_tuple_t = ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>;
+                result.template emplace<error_tuple_t>(::beman::execution::set_error, ::std::current_exception());
+                [[maybe_unused]] auto queue = waiting_states.pop_all_and_shutdown();
+                assert(queue.empty());
+            }
+        }
+#line 163 "include/beman/execution/detail/split.hpp"
+        void add_listener(local_state_base* listener) noexcept {
+
+#line 166 "include/beman/execution/detail/split.hpp"
+            if (auto maybe_ptr = waiting_states.try_push(listener); !maybe_ptr) {
+
+                listener->notify();
+            } else if (!(*maybe_ptr)) {
+
+                assert(op_state);
+                if (op_state)
+                    ::beman::execution::start(*op_state);
+                else
+                    std::terminate();
+            }
+        }
+#line 179 "include/beman/execution/detail/split.hpp"
+        void notify() noexcept {
+
+#line 183 "include/beman/execution/detail/split.hpp"
+            op_state.reset();
+            auto listeners = waiting_states.pop_all_and_shutdown();
+            while (auto listener = listeners.pop()) {
+                listener->notify();
+            }
+        }
+#line 190 "include/beman/execution/detail/split.hpp"
+        void inc_ref() noexcept { ref_count.fetch_add(1); }
+
+#line 201 "include/beman/execution/detail/split.hpp"
+        void dec_ref() noexcept {
+            std::size_t count = ref_count.load();
+            if (count == 2 && waiting_states.empty_and_not_shutdown()) {
+                assert(op_state);
+                [[maybe_unused]] auto listeners = waiting_states.pop_all_and_shutdown();
+                assert(listeners.empty());
+                op_state.reset();
+            }
+            if (ref_count.fetch_sub(1) == 1) {
+                delete this;
+            }
+        }
+#line 214 "include/beman/execution/detail/split.hpp"
+        ::beman::execution::inplace_stop_source stop_src{};
+        variant_type                            result{};
+        state_list_type                         waiting_states{};
+        ::std::atomic<::std::size_t>            ref_count{0};
+        ::std::optional<child_operation_state>  op_state{};
+    };
+
+    template <class Sndr, class Receiver>
+    struct local_state final : local_state_base {
+        using stop_token_type = ::beman::execution::stop_token_of_t<::beman::execution::env_of_t<Receiver>>;
+
+        struct on_stop_type {
+            shared_state<Sndr>* sh_state;
+            void                operator()() noexcept { sh_state->stop_src.request_stop(); }
+        };
+
+        using on_stop_callback = ::beman::execution::stop_callback_for_t<stop_token_type, on_stop_type>;
+
+        explicit local_state(shared_state<Sndr>* state, Receiver& rcvr) noexcept
+            : sh_state(state), receiver{std::addressof(rcvr)} {
+            sh_state->inc_ref();
+        }
+#line 237 "include/beman/execution/detail/split.hpp"
+        ~local_state() noexcept { sh_state->dec_ref(); }
+
+        local_state(const local_state&)            = delete;
+        local_state& operator=(const local_state&) = delete;
+        local_state(local_state&&)                 = delete;
+        local_state& operator=(local_state&&)      = delete;
+
+        auto notify() noexcept -> void override {
+            on_stop.reset();
+            auto stop_token = ::beman::execution::get_stop_token(::beman::execution::get_env(receiver));
+            if (stop_token.stop_requested()) {
+                ::beman::execution::set_stopped(std::move(*receiver));
+            } else {
+                assert(sh_state->result.index() > 0);
+                assert(!sh_state->result.valueless_by_exception());
+                try {
+                    ::std::visit(
+                        [&]<class Arg>(const Arg& arg) noexcept -> void {
+                            if constexpr (!::std::same_as<::std::decay_t<Arg>, ::std::monostate>) {
+                                ::std::apply(
+                                    [&](auto tag, const auto&... args) noexcept -> void {
+                                        tag(::std::move(*receiver), args...);
+                                    },
+                                    arg);
+                            }
+                        },
+                        sh_state->result);
+                } catch (...) {
+
+#line 267 "include/beman/execution/detail/split.hpp"
+                    std::terminate();
+                }
+            }
+        }
+#line 272 "include/beman/execution/detail/split.hpp"
+        void start() noexcept {
+            on_stop.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(*receiver)),
+                            on_stop_type{sh_state});
+            sh_state->add_listener(this);
+        }
+#line 278 "include/beman/execution/detail/split.hpp"
+        std::optional<on_stop_callback> on_stop;
+        shared_state<Sndr>*             sh_state;
+        Receiver*                       receiver;
+    };
+
+    static constexpr auto get_state = []<typename Sender, typename Receiver>(Sender&&  sender,
+                                                                             Receiver& receiver) noexcept {
+        auto&& wrapper = sender.template get<1>();
+        return local_state(wrapper.sh_state, receiver);
+    };
+
+    static constexpr auto start = []<class Sndr, class Rcvr>(local_state<Sndr, Rcvr>& state, Rcvr&) noexcept {
+        state.start();
+    };
+};
+
+template <class Sndr>
+struct shared_wrapper {
+    explicit shared_wrapper(impls_for<split_impl_t>::shared_state<Sndr>* state) noexcept : sh_state(state) {
+        if (sh_state) {
+            sh_state->inc_ref();
+        }
+    }
+#line 302 "include/beman/execution/detail/split.hpp"
+    ~shared_wrapper() noexcept {
+        if (sh_state) {
+            sh_state->dec_ref();
+        }
+    }
+#line 308 "include/beman/execution/detail/split.hpp"
+    shared_wrapper(const shared_wrapper& other) noexcept : sh_state(other.sh_state) {
+        if (sh_state) {
+            sh_state->inc_ref();
+        }
+    }
+#line 314 "include/beman/execution/detail/split.hpp"
+    shared_wrapper(shared_wrapper&& other) noexcept : sh_state(::std::exchange(other.sh_state, nullptr)) {}
+
+    shared_wrapper& operator=(const shared_wrapper& other) noexcept {
+
+#line 319 "include/beman/execution/detail/split.hpp"
+        if (this == &other) {
+            return *this;
+        }
+        auto tmp = other;
+        ::std::swap(sh_state, tmp.sh_state);
+        return *this;
+    }
+#line 327 "include/beman/execution/detail/split.hpp"
+    shared_wrapper& operator=(shared_wrapper&& other) noexcept {
+        auto tmp = ::std::move(other);
+        ::std::swap(sh_state, tmp.sh_state);
+        return *this;
+    }
+#line 333 "include/beman/execution/detail/split.hpp"
+    impls_for<split_impl_t>::shared_state<Sndr>* sh_state;
+};
+
+struct split_t {
+    template <class Sndr>
+    auto transform_sender(Sndr&& sndr) const {
+        auto&& child       = ::std::forward<Sndr>(sndr).template get<2>();
+        using child_type   = decltype(child);
+        using shared_state = ::beman::execution::detail::impls_for<split_impl_t>::shared_state<child_type>;
+        auto* sh_state     = new shared_state{::beman::execution::detail::forward_like<Sndr>(child)};
+        return ::beman::execution::detail::make_sender(split_impl_t{}, shared_wrapper<child_type>{sh_state});
+    }
+#line 346 "include/beman/execution/detail/split.hpp"
+    template <class Sender>
+        requires beman::execution::sender_in<Sender, impls_for<split_impl_t>::split_env>
+    auto operator()(Sender&& sender) const {
+        auto domain{::beman::execution::detail::get_domain_early(sender)};
+        return ::beman::execution::transform_sender(
+            domain, ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)));
+    }
+};
+
+template <class Sndr, class Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::split_impl_t,
+                                             ::beman::execution::detail::shared_wrapper<Sndr>>,
+    Env> {
+    template <class... Args>
+    using make_value_completions =
+        ::beman::execution::completion_signatures<::beman::execution::set_value_t(const std::decay_t<Args>&...)>;
+
+    template <class... Args>
+    using make_error_completions =
+        ::beman::execution::completion_signatures<::beman::execution::set_error_t(const std::decay_t<Args>&)...>;
+
+    using value_completions = ::beman::execution::
+        value_types_of_t<Sndr, Env, make_value_completions, ::beman::execution::detail::meta::combine>;
+
+    using error_completions = ::beman::execution::error_types_of_t<Sndr, Env, make_error_completions>;
+
+    using fixed_completions =
+        ::beman::execution::completion_signatures<::beman::execution::set_stopped_t(),
+                                                  ::beman::execution::set_error_t(std::exception_ptr)>;
+
+    using type = ::beman::execution::detail::meta::unique<
+        ::beman::execution::detail::meta::combine<fixed_completions, value_completions, error_completions>>;
+};
+
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using split_t = ::beman::execution::detail::split_t;
+
+export /* --------- */ inline constexpr ::beman::execution::split_t split{};
+} // namespace beman::execution
+
+#line 37 "include/beman/execution/detail/then.hpp"
+namespace beman::execution::detail {
+template <typename Completion>
+struct then_t : ::beman::execution::sender_adaptor_closure<then_t<Completion>> {
+    template <::beman::execution::detail::movable_value Fun>
+    auto operator()(Fun&& fun) const {
+        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Fun>(fun)};
+    }
+    template <::beman::execution::sender Sender, ::beman::execution::detail::movable_value Fun>
+    auto operator()(Sender&& sender, Fun&& fun) const {
+        auto domain{::beman::execution::detail::get_domain_early(sender)};
+        return ::beman::execution::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(*this, ::std::forward<Fun>(fun), ::std::forward<Sender>(sender)));
+    }
+    template <::beman::execution::sender Sender, typename Env>
+        requires ::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>
+    static auto affine_on(Sender&& sndr, const Env&) noexcept {
+        return ::std::forward<Sender>(sndr);
+    }
+};
+
+template <typename Completion>
+struct impls_for<then_t<Completion>> : ::beman::execution::detail::default_impls {
+    // NOLINTBEGIN(bugprone-exception-escape)
+    static constexpr auto complete =
+        []<typename Tag, typename... Args>(auto, auto& fun, auto& receiver, Tag, Args&&... args) noexcept -> void {
+        if constexpr (::std::same_as<Completion, Tag>) {
+            try {
+                auto invoke = [&] { return ::std::invoke(::std::move(fun), ::std::forward<Args>(args)...); };
+                if constexpr (::std::same_as<void, decltype(invoke())>) {
+                    invoke();
+                    ::beman::execution::set_value(::std::move(receiver));
+                } else {
+                    ::beman::execution::set_value(::std::move(receiver), invoke());
+                }
+            } catch (...) {
+                if constexpr (not noexcept(::std::invoke(::std::move(fun), ::std::forward<Args>(args)...)
+
+                                               )) {
+                    static_assert(
+                        noexcept(::beman::execution::set_error(::std::move(receiver), ::std::current_exception())));
+                    ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
+                }
+            }
+        } else {
+            static_assert(noexcept(Tag()(::std::move(receiver), ::std::forward<Args>(args)...)));
+            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
+        }
+    };
+    // NOLINTEND(bugprone-exception-escape)
+};
+
+template <typename T>
+struct then_set_value {
+    using type = ::beman::execution::set_value_t(T);
+};
+template <>
+struct then_set_value<void> {
+    using type = ::beman::execution::set_value_t();
+};
+
+template <typename, typename, typename Completion>
+struct then_transform {
+    using type = Completion;
+};
+
+template <typename Fun, typename Completion, typename... T>
+struct then_transform<Fun, Completion, Completion(T...)> {
+    using type = typename ::beman::execution::detail::then_set_value<
+        ::beman::execution::detail::call_result_t<Fun, T...>>::type;
+};
+
+template <typename Fun, typename Replace>
+struct then_transform_t {
+    template <typename Completion>
+    using transform = typename ::beman::execution::detail::then_transform<Fun, Replace, Completion>::type;
+};
+
+template <typename, typename, typename>
+struct then_exception_fun : ::std::false_type {};
+template <typename Comp, typename Fun, typename... A>
+struct then_exception_fun<Comp, Fun, Comp(A...)>
+    : ::std::bool_constant<not noexcept(::std::declval<Fun>()(::std::declval<A>()...))> {};
+
+template <typename, typename, typename>
+struct then_exception : ::std::false_type {};
+template <typename Comp, typename Fun, typename Completion, typename... Completions>
+struct then_exception<Comp, Fun, ::beman::execution::completion_signatures<Completion, Completions...>> {
+    static constexpr bool value{
+        then_exception_fun<Comp, Fun, Completion>::value ||
+        then_exception<Comp, Fun, ::beman::execution::completion_signatures<Completions...>>::value};
+};
+
+template <typename Completion, typename Fun, typename Sender, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::then_t<Completion>, Fun, Sender>,
+    Env> {
+    using type = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::combine<
+        ::beman::execution::detail::meta::transform<
+            ::beman::execution::detail::then_transform_t<Fun, Completion>::template transform,
+            ::beman::execution::completion_signatures_of_t<Sender, Env>>,
+        ::std::conditional_t<
+            ::beman::execution::detail::
+                then_exception<Completion, Fun, ::beman::execution::completion_signatures_of_t<Sender, Env>>::value,
+            ::beman::execution::completion_signatures<::beman::execution::set_error_t(::std::exception_ptr)>,
+            ::beman::execution::completion_signatures<>>>>;
+};
+} // namespace beman::execution::detail
+
+#line 148 "include/beman/execution/detail/then.hpp"
+namespace beman::execution {
+
+#line 153 "include/beman/execution/detail/then.hpp"
+export /* --------- */ using then_t = ::beman::execution::detail::then_t<::beman::execution::set_value_t>;
+
+#line 158 "include/beman/execution/detail/then.hpp"
+export /* --------- */ using upon_error_t = ::beman::execution::detail::then_t<::beman::execution::set_error_t>;
+
+#line 163 "include/beman/execution/detail/then.hpp"
+export /* --------- */ using upon_stopped_t = ::beman::execution::detail::then_t<::beman::execution::set_stopped_t>;
+
+#line 215 "include/beman/execution/detail/then.hpp"
+export /* --------- */ inline constexpr ::beman::execution::then_t then{};
+
+#line 269 "include/beman/execution/detail/then.hpp"
+export /* --------- */ inline constexpr ::beman::execution::upon_error_t upon_error{};
+
+#line 320 "include/beman/execution/detail/then.hpp"
+export /* --------- */ inline constexpr ::beman::execution::upon_stopped_t upon_stopped{};
+} // namespace beman::execution
+
+#line 51 "include/beman/execution/detail/when_all.hpp"
+namespace beman::execution::detail {
+struct when_all_t {
+    template <::beman::execution::sender... Sender>
+        requires(0u != sizeof...(Sender)) &&
+                ((::beman::execution::detail::meta::size_v<
+                      ::beman::execution::value_types_of_t<Sender,
+                                                           ::beman::execution::env<>,
+                                                           ::std::tuple,
+                                                           ::beman::execution::detail::type_list>> == 1u) &&
+                 ...) &&
+                requires(Sender&&... s) {
+                    typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(s))...>;
+                }
+    auto operator()(Sender&&... sender) const {
+        using common_t =
+            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
+        return ::beman::execution::transform_sender(
+            common_t(), ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)...));
+    }
+};
+
+template <typename>
+struct when_all_value_types;
+template <typename... T>
+struct when_all_value_types<::beman::execution::detail::type_list<T...>> {
+    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t(T...)>;
+};
+
+template <>
+struct impls_for<::beman::execution::detail::when_all_t> : ::beman::execution::detail::default_impls {
+    static constexpr auto get_attrs{[](auto&&, auto&&... sender) {
+        using common_t =
+            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
+        if constexpr (::std::same_as<common_t, ::beman::execution::default_domain>)
+            return ::beman::execution::env<>{};
+        else
+            return ::beman::execution::detail::make_env(::beman::execution::get_domain, common_t{});
+    }};
+    static constexpr auto get_env{
+        []<typename State, typename Receiver>(auto&&, State& state, const Receiver& receiver) noexcept {
+            return ::beman::execution::detail::join_env(
+                ::beman::execution::detail::make_env(::beman::execution::get_stop_token, state.stop_src.get_token()),
+                ::beman::execution::get_env(receiver));
+        }};
+
+    enum class disposition : unsigned char { started, error, stopped };
+
+    template <typename Receiver, typename... Sender>
+    struct state_type {
+        struct nonesuch {};
+        using env_t        = ::beman::execution::env_of_t<Receiver>;
+        using values_tuple = ::std::tuple<
+            ::beman::execution::
+                value_types_of_t<Sender, env_t, ::beman::execution::detail::decayed_tuple, ::std::optional>...>;
+        using errors_variant = ::beman::execution::detail::meta::to<
+            ::std::variant,
+            ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
+                nonesuch,
+                ::beman::execution::detail::meta::prepend<
+                    ::std::exception_ptr,
+                    ::beman::execution::detail::meta::combine<::beman::execution::detail::meta::to<
+                        ::beman::execution::detail::type_list,
+                        ::beman::execution::detail::meta::combine<::beman::execution::error_types_of_t<
+                            Sender,
+                            env_t,
+                            ::beman::execution::detail::decayed_type_list>...>>>>>>>;
+        using stop_callback = ::beman::execution::stop_callback_for_t<
+            ::beman::execution::stop_token_of_t<::beman::execution::env_of_t<Receiver>>,
+            ::beman::execution::detail::on_stop_request<state_type>>;
+
+        void arrive(Receiver& recvr) noexcept {
+            if (0u == --count)
+                this->complete(recvr);
+        }
+#line 126 "include/beman/execution/detail/when_all.hpp"
+        void complete(Receiver& recvr) noexcept {
+            switch (disposition(this->disp)) {
+            case disposition::started: {
+                auto tie = []<typename... T>(::std::tuple<T...>& t) noexcept {
+                    return ::std::apply([](auto&... a) { return ::std::tie(a...); }, t);
+                };
+                auto set = [&](auto&... t) noexcept {
+                    ::beman::execution::set_value(::std::move(recvr), ::std::move(t)...);
+                };
+
+                this->on_stop.reset();
+                ::std::apply([&](auto&... opts) noexcept { ::std::apply(set, ::std::tuple_cat(tie(*opts)...)); },
+                             this->values);
+            } break;
+            case disposition::error:
+                this->on_stop.reset();
+                try {
+                    ::std::visit(
+                        [&]<typename Error>(Error& error) noexcept {
+                            if constexpr (!::std::same_as<Error, nonesuch>) {
+                                ::beman::execution::set_error(::std::move(recvr), ::std::move(error));
+                            }
+                        },
+                        this->errors);
+                } catch (...) {
+                    ::beman::execution::set_error(::std::move(recvr), ::std::current_exception());
+                }
+                break;
+            case disposition::stopped:
+                this->on_stop.reset();
+                ::beman::execution::set_stopped(::std::move(recvr));
+                break;
+            }
+        }
+#line 161 "include/beman/execution/detail/when_all.hpp"
+        auto request_stop() -> void {
+            if (1u == ++this->count)
+                --this->count;
+            else {
+                this->stop_src.request_stop();
+                this->arrive(*this->receiver);
+            }
+        }
+#line 170 "include/beman/execution/detail/when_all.hpp"
+        Receiver*                               receiver{};
+        ::std::atomic<::std::size_t>            count{sizeof...(Sender)};
+        ::beman::execution::inplace_stop_source stop_src{};
+        ::std::atomic<disposition>              disp{disposition::started};
+        errors_variant                          errors{};
+        values_tuple                            values{};
+        ::std::optional<stop_callback>          on_stop{::std::nullopt};
+    };
+
+    template <typename Receiver>
+    struct make_state {
+        template <::beman::execution::sender_in<::beman::execution::env_of_t<Receiver>>... Sender>
+        auto operator()(auto, auto, Sender&&...) const {
+            return state_type<Receiver, Sender...>{};
+        }
+    };
+    static constexpr auto get_state{[]<typename Sender, typename Receiver>(Sender&& sender, Receiver&) noexcept(
+                                        noexcept(std::forward<Sender>(sender).apply(make_state<Receiver>{}))) {
+        return std::forward<Sender>(sender).apply(make_state<Receiver>{});
+    }};
+    static constexpr auto start{[]<typename State, typename Receiver, typename... Ops>(
+                                    State& state, Receiver& receiver, Ops&... ops) noexcept -> void {
+        state.receiver = &receiver;
+        state.on_stop.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(receiver)),
+                              ::beman::execution::detail::on_stop_request{state});
+        if (state.stop_src.stop_requested()) {
+            state.on_stop.reset();
+            ::beman::execution::set_stopped(std::move(receiver));
+        } else {
+            (::beman::execution::start(ops), ...);
+        }
+    }};
+    static constexpr auto complete{
+        []<typename Index, typename State, typename Receiver, typename Set, typename... Args>(
+            Index, State& state, Receiver& receiver, Set, Args&&... args) noexcept -> void {
+            if constexpr (::std::same_as<Set, ::beman::execution::set_error_t>) {
+                if (disposition::error != state.disp.exchange(disposition::error)) {
+                    state.stop_src.request_stop();
+                    try {
+                        state.errors.template emplace<typename ::std::decay<Args...>::type>(
+                            ::std::forward<Args>(args)...);
+                    } catch (...) {
+                        state.errors.template emplace<::std::exception_ptr>(::std::current_exception());
+                    }
+                }
+            } else if constexpr (::std::same_as<Set, ::beman::execution::set_stopped_t>) {
+                auto expected = disposition::started;
+                if (state.disp.compare_exchange_strong(expected, disposition::stopped)) {
+                    state.stop_src.request_stop();
+                }
+            } else if constexpr (!::std::same_as<decltype(State::values), ::std::tuple<>>) {
+                if (state.disp == disposition::started) {
+                    auto& opt = ::std::get<Index::value>(state.values);
+                    try {
+                        opt.emplace(::std::forward<Args>(args)...);
+                    } catch (...) {
+                        if (disposition::error != state.disp.exchange(disposition::error)) {
+                            state.stop_src.request_stop();
+                            state.errors.template emplace<::std::exception_ptr>(::std::current_exception());
+                        }
+                    }
+                }
+            }
+            state.arrive(receiver);
+        }};
+};
+
+template <typename Data, typename Env, typename... Sender>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::when_all_t, Data, Sender...>,
+    Env> {
+    template <typename... E>
+    struct error_comps_t {
+        using type = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
+    };
+    template <typename... E>
+    using error_comps = typename error_comps_t<E...>::type;
+
+    using value_types =
+        typename ::beman::execution::detail::when_all_value_types<::beman::execution::detail::meta::combine<
+            ::beman::execution::
+                value_types_of_t<Sender, Env, ::beman::execution::detail::type_list, ::std::type_identity_t>...>>::
+            type;
+    using error_types = ::beman::execution::detail::meta::unique<
+        ::beman::execution::detail::meta::combine<::beman::execution::error_types_of_t<Sender, Env, error_comps>...>>;
+    using stopped_types =
+        ::std::conditional_t<(false || ... || ::beman::execution::sends_stopped<Sender, Env>),
+                             ::beman::execution::completion_signatures<::beman::execution::set_stopped_t()>,
+                             ::beman::execution::completion_signatures<>>;
+    using type = ::beman::execution::detail::meta::combine<value_types, error_types, stopped_types>;
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using when_all_t = ::beman::execution::detail::when_all_t;
+export /* --------- */ inline constexpr ::beman::execution::when_all_t when_all{};
+} // namespace beman::execution
+
+#line 21 "include/beman/execution/detail/write_env.hpp"
+namespace beman::execution::detail {
+struct write_env_t {
+    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
+    constexpr auto operator()(Sender&& sender, Env&& env) const {
+        return ::beman::execution::detail::make_sender(
+            *this, ::std::forward<Env>(env), ::std::forward<Sender>(sender));
+    }
+    static auto name() { return "write_env_t"; }
+    template <::beman::execution::sender Sender, typename Env>
+        requires ::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>
+    static auto affine_on(Sender&& sndr, const Env&) noexcept {
+        return ::std::forward<Sender>(sndr);
+    }
+};
+
+template <typename NewEnv, typename Child, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::write_env_t, NewEnv, Child>,
+    Env> {
+    using type = decltype(::beman::execution::get_completion_signatures(
+        ::std::declval<Child>(),
+        ::beman::execution::detail::join_env(::std::declval<NewEnv>(), ::std::declval<Env>())));
+};
+
+template <>
+struct impls_for<write_env_t> : ::beman::execution::detail::default_impls {
+    static constexpr auto get_env = [](auto, const auto& state, const auto& receiver) noexcept {
+        return ::beman::execution::detail::join_env(state, ::beman::execution::get_env(receiver));
+    };
+};
+
+inline constexpr write_env_t write_env{};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using write_env_t = ::beman::execution::detail::write_env_t;
+export /* --------- */ inline constexpr write_env_t write_env{};
+} // namespace beman::execution
+
+#line 23 "include/beman/execution/detail/associate.hpp"
+namespace beman::execution::detail {
+export /* --------- */ template <::beman::execution::scope_token Token, ::beman::execution::sender Sender>
+struct associate_data {
+    using wrap_sender = ::std::remove_cvref_t<decltype(::std::declval<Token&>().wrap(::std::declval<Sender>()))>;
+
+    explicit associate_data(Token t, Sender&& s) : token(t), sender(this->token.wrap(::std::forward<Sender>(s))) {
+        if (!token.try_associate()) {
+            this->sender.reset();
+        }
+    }
+    associate_data(const associate_data& other) noexcept(::std::is_nothrow_copy_constructible_v<wrap_sender> &&
+                                                         noexcept(token.try_associate()))
+        : token(other.token), sender() {
+        if (other.sender && this->token.try_associate()) {
+            try {
+                this->sender.emplace(*other.sender);
+            } catch (...) {
+                this->token.disassociate();
+            }
+        }
+    }
+    associate_data(associate_data&& other) noexcept(::std::is_nothrow_move_constructible_v<wrap_sender>)
+        : token(other.token), sender(::std::move(other.sender)) {
+        other.sender.reset();
+    }
+    auto operator=(const associate_data&) -> associate_data& = delete;
+    auto operator=(associate_data&&) -> associate_data&      = delete;
+    ~associate_data() {
+        if (this->sender) {
+            this->sender.reset();
+            this->token.disassociate();
+        }
+    }
+#line 58 "include/beman/execution/detail/associate.hpp"
+    auto release() -> ::std::optional<::std::pair<Token, wrap_sender>> {
+        return this->sender ? (std::unique_ptr<std::optional<wrap_sender>, decltype([](auto* opt) { opt->reset(); })>(
+                                   &this->sender),
+                               ::std::optional{::std::pair{::std::move(this->token), ::std::move(*this->sender)}})
+                            : ::std::optional<::std::pair<Token, wrap_sender>>{};
+    }
+#line 65 "include/beman/execution/detail/associate.hpp"
+    Token                        token;
+    ::std::optional<wrap_sender> sender;
+};
+export /* --------- */ template <::beman::execution::scope_token Token, ::beman::execution::sender Sender>
+associate_data(Token, Sender&&) -> associate_data<Token, Sender>;
+
+struct associate_t {
+    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token>
+    auto operator()(Sender&& sender, Token&& token) const {
+        auto domain(::beman::execution::detail::get_domain_early(sender));
+        return ::beman::execution::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(
+                *this,
+                ::beman::execution::detail::associate_data(::std::forward<Token>(token),
+                                                           ::std::forward<Sender>(sender))));
+    }
+};
+
+template <>
+struct impls_for<associate_t> : ::beman::execution::detail::default_impls {
+    template <typename, typename>
+    struct get_noexcept : ::std::false_type {};
+    template <typename Tag, typename Data, typename Receiver>
+    struct get_noexcept<::beman::execution::detail::basic_sender<Tag, Data>, Receiver>
+        : ::std::bool_constant<
+              ::std::is_nothrow_move_constructible_v<typename ::std::remove_cvref_t<Data>::wrap_sender>&& ::beman::
+                  execution::detail::nothrow_callable<::beman::execution::connect_t,
+                                                      typename ::std::remove_cvref_t<Data>::wrap_sender,
+                                                      Receiver>> {};
+
+    static constexpr auto get_state =
+        []<typename Sender, typename Receiver>(Sender&& sender, Receiver& receiver) noexcept(
+            ::std::is_nothrow_constructible_v<::std::remove_cvref_t<Sender>, Sender>&&
+                get_noexcept<::std::remove_cvref_t<Sender>, Receiver>::value) {
+            auto [_, data] = ::std::forward<Sender>(sender);
+            auto dataParts{data.release()};
+
+            using scope_token = decltype(dataParts->first);
+            using wrap_sender = decltype(dataParts->second);
+            using op_t        = decltype(::beman::execution::connect(::std::move(dataParts->second),
+                                                              ::std::forward<Receiver>(receiver)));
+
+            struct op_state {
+                using sop_t        = op_t;
+                using sscope_token = scope_token;
+                struct assoc_t {
+                    sscope_token tok;
+                    sop_t        op;
+                };
+
+                bool associated{false};
+                union {
+                    Receiver* rcvr;
+                    assoc_t   assoc;
+                };
+                explicit op_state(Receiver& r) noexcept : rcvr(::std::addressof(r)) {}
+                explicit op_state(sscope_token tk, wrap_sender&& sndr, Receiver& r) try
+                    : associated(true), assoc(tk, ::beman::execution::connect(::std::move(sndr), ::std::move(r))) {
+                } catch (...) {
+                    tk.disassociate();
+                    throw;
+                }
+                op_state(op_state&&) = delete;
+                ~op_state() {
+                    if (this->associated) {
+                        this->assoc.op.~sop_t();
+                        this->assoc.tok.disassociate();
+                        this->assoc.tok.~sscope_token();
+                    }
+                }
+                auto run() noexcept -> void {
+                    if (this->associated) {
+                        ::beman::execution::start(this->assoc.op);
+                    } else {
+                        ::beman::execution::set_stopped(::std::move(*this->rcvr));
+                    }
+                }
+            };
+            return dataParts ? op_state(::std::move(dataParts->first), ::std::move(dataParts->second), receiver)
+                             : op_state(receiver);
+        };
+    static constexpr auto start = [](auto& state, auto&&) noexcept -> void { state.run(); };
+};
+
+template <typename Data, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::associate_t, Data>,
+    Env> {
+    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t()>;
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using associate_t = ::beman::execution::detail::associate_t;
+export /* --------- */ inline constexpr associate_t associate{};
+} // namespace beman::execution
+
+#line 19 "include/beman/execution/detail/as_awaitable.hpp"
+namespace beman::execution {
+
+#line 24 "include/beman/execution/detail/as_awaitable.hpp"
+export /* --------- */ struct as_awaitable_t {
+    template <typename Expr, typename Promise>
+    auto operator()(Expr&& expr, Promise& promise) const {
+        if constexpr (requires { ::std::forward<Expr>(expr).as_awaitable(promise); }) {
+            static_assert(
+                ::beman::execution::detail::is_awaitable<decltype(::std::forward<Expr>(expr).as_awaitable(promise)),
+                                                         Promise>,
+                "as_awaitable must return an awaitable");
+            return ::std::forward<Expr>(expr).as_awaitable(promise);
+        } else if constexpr (::beman::execution::detail::
+                                 is_awaitable<Expr, ::beman::execution::detail::unspecified_promise> ||
+                             !::beman::execution::detail::awaitable_sender<Expr, Promise>) {
+            return ::std::forward<Expr>(expr);
+        } else {
+            return ::beman::execution::detail::sender_awaitable<Expr, Promise>{::std::forward<Expr>(expr), promise};
+        }
+    }
+};
+export /* --------- */ inline constexpr ::beman::execution::as_awaitable_t as_awaitable{};
+} // namespace beman::execution
+
+#line 26 "include/beman/execution/detail/counting_scope_join.hpp"
+namespace beman::execution::detail {
+struct counting_scope_join_t {
+    template <::beman::execution::receiver>
+    struct state;
+
+    auto operator()(::beman::execution::detail::counting_scope_base* ptr) const {
+        return ::beman::execution::detail::make_sender(*this, ptr);
+    }
+};
+inline constexpr counting_scope_join_t counting_scope_join{};
+
+template <typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::counting_scope_join_t,
+                                             ::beman::execution::detail::counting_scope_base*>,
+    Env> {
+    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t()>;
+};
+
+} // namespace beman::execution::detail
+
+#line 49 "include/beman/execution/detail/counting_scope_join.hpp"
+template <::beman::execution::receiver Receiver>
+struct beman::execution::detail::counting_scope_join_t::state : ::beman::execution::detail::counting_scope_base::node {
+    using op_t = decltype(::beman::execution::connect(::beman::execution::schedule(::beman::execution::get_scheduler(
+                                                          ::beman::execution::get_env(::std::declval<Receiver&>()))),
+                                                      ::std::declval<Receiver&>()));
+
+    ::beman::execution::detail::counting_scope_base* scope;
+    explicit state(::beman::execution::detail::counting_scope_base* s, Receiver& r)
+        : scope(s),
+          receiver(r),
+          op(::beman::execution::connect(::beman::execution::schedule(::beman::execution::get_scheduler(
+                                             ::beman::execution::get_env(this->receiver))),
+                                         this->receiver)) {}
+    virtual ~state() = default;
+
+    auto complete() noexcept -> void override { ::beman::execution::start(this->op); }
+    auto complete_inline() noexcept -> void override { ::beman::execution::set_value(::std::move(this->receiver)); }
+
+    auto start() noexcept -> void { this->scope->start_node(this); }
+
+    ::std::remove_cvref_t<Receiver>& receiver;
+    op_t                             op;
+};
+
+#line 75 "include/beman/execution/detail/counting_scope_join.hpp"
+namespace beman::execution::detail {
+template <>
+struct impls_for<::beman::execution::detail::counting_scope_join_t> : ::beman::execution::detail::default_impls {
+    static constexpr auto get_state = []<typename Receiver>(auto&& sender, Receiver& receiver) noexcept(false) {
+        auto [_, self] = sender;
+        return ::beman::execution::detail::counting_scope_join_t::state<Receiver>(self, receiver);
+    };
+    static constexpr auto start = [](auto& s, auto&) noexcept { s.start(); };
+};
+} // namespace beman::execution::detail
+
+#line 36 "include/beman/execution/detail/affine_on.hpp"
+namespace beman::execution::detail {
+template <typename Ev>
+struct affine_on_env {
+    Ev   ev_;
+    auto query(const ::beman::execution::get_stop_token_t&) const noexcept -> ::beman::execution::never_stop_token {
+        return ::beman::execution::never_stop_token();
+    }
+    template <typename Q>
+    auto query(const Q& q) const noexcept -> decltype(q(this->ev_)) {
+        return q(this->ev_);
+    }
+};
+template <typename Ev>
+affine_on_env(const Ev&) -> affine_on_env<Ev>;
+
+#line 59 "include/beman/execution/detail/affine_on.hpp"
+struct affine_on_t : ::beman::execution::sender_adaptor_closure<affine_on_t> {
+
+#line 67 "include/beman/execution/detail/affine_on.hpp"
+    template <::beman::execution::sender Sender>
+    auto operator()(Sender&& sender) const {
+        return ::beman::execution::detail::transform_sender(
+            ::beman::execution::detail::get_domain_early(sender),
+            ::beman::execution::detail::make_sender(
+                *this, ::beman::execution::env<>{}, ::std::forward<Sender>(sender)));
+    }
+#line 80 "include/beman/execution/detail/affine_on.hpp"
+    auto operator()() const { return ::beman::execution::detail::sender_adaptor{*this}; }
+
+#line 100 "include/beman/execution/detail/affine_on.hpp"
+    template <::beman::execution::sender Sender, typename Env>
+        requires ::beman::execution::detail::sender_for<Sender, affine_on_t> && requires(const Env& env) {
+            { ::beman::execution::get_scheduler(env) } -> ::beman::execution::scheduler;
+            { ::beman::execution::schedule(::beman::execution::get_scheduler(env)) } -> ::beman::execution::sender;
+            {
+                ::beman::execution::get_completion_signatures(
+                    ::beman::execution::schedule(::beman::execution::get_scheduler(env)),
+                    ::beman::execution::detail::join_env(
+                        ::beman::execution::env{::beman::execution::prop{
+                            ::beman::execution::get_stop_token, ::beman::execution::never_stop_token{}, {}}},
+                        env))
+            } -> ::std::same_as<::beman::execution::completion_signatures<::beman::execution::set_value_t()>>;
+        }
+    static auto transform_sender(Sender&& sender, const Env& ev) {
+        [[maybe_unused]] auto& [tag, data, child] = sender;
+        using child_tag_t = ::beman::execution::tag_of_t<::std::remove_cvref_t<decltype(child)>>;
+
+        if constexpr (::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>) {
+            constexpr child_tag_t t{};
+            return t.affine_on(::beman::execution::detail::forward_like<Sender>(child), ev);
+        } else {
+            return ::beman::execution::write_env(
+                ::beman::execution::schedule_from(
+                    ::beman::execution::get_scheduler(ev),
+                    ::beman::execution::write_env(::beman::execution::detail::forward_like<Sender>(child), ev)),
+                beman::execution::detail::affine_on_env(ev));
+        }
+    }
+};
+
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+
+#line 137 "include/beman/execution/detail/affine_on.hpp"
+export /* --------- */ using affine_on_t = beman::execution::detail::affine_on_t;
+export /* --------- */ inline constexpr affine_on_t affine_on{};
+} // namespace beman::execution
+
+#line 32 "include/beman/execution/detail/continues_on.hpp"
+namespace beman::execution::detail {
+
+#line 39 "include/beman/execution/detail/continues_on.hpp"
+struct continues_on_t {
+    template <::beman::execution::detail::sender_for<continues_on_t> Sender, typename... Env>
+    static auto transform_sender(Sender&& sender, Env&&...) {
+        auto&& data{sender.template get<1>()};
+        auto&& child{sender.template get<2>()};
+        return ::beman::execution::schedule_from(std::move(data), std::move(child));
+    }
+    template <::beman::execution::scheduler Scheduler>
+    auto operator()(Scheduler&& scheduler) const {
+        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Scheduler>(scheduler)};
+    }
+    template <::beman::execution::sender Sender, ::beman::execution::scheduler Scheduler>
+    auto operator()(Sender&& sender, Scheduler&& scheduler) const {
+        auto domain(::beman::execution::detail::get_domain_early(sender));
+        return ::beman::execution::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(
+                *this, std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
+    }
+};
+
+#line 65 "include/beman/execution/detail/continues_on.hpp"
+template <>
+struct impls_for<::beman::execution::detail::continues_on_t> : ::beman::execution::detail::default_impls {
+    static constexpr auto get_attrs{[](const auto& data, const auto& child) noexcept -> decltype(auto) {
+        return ::beman::execution::detail::join_env(
+            ::beman::execution::detail::sched_attrs(data),
+            ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
+    }};
+};
+
+#line 79 "include/beman/execution/detail/continues_on.hpp"
+template <::beman::execution::detail::sender_for<::beman::execution::detail::continues_on_t> Sender, typename Env>
+auto get_domain_late(Sender&& sender, Env&&) {
+    auto scheduler{sender.template get<1>()};
+    return ::beman::execution::detail::query_with_default(
+        ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{});
+}
+} // namespace beman::execution::detail
+
+#line 89 "include/beman/execution/detail/continues_on.hpp"
+namespace beman::execution {
+export /* --------- */ using continues_on_t = ::beman::execution::detail::continues_on_t;
+
+#line 95 "include/beman/execution/detail/continues_on.hpp"
+export /* --------- */ inline constexpr continues_on_t continues_on{};
+} // namespace beman::execution
+
+#line 26 "include/beman/execution/detail/starts_on.hpp"
+namespace beman::execution::detail {
+struct starts_on_t {
+    template <::beman::execution::detail::sender_for<::beman::execution::detail::starts_on_t> Sender, typename Env>
+    auto transform_env(Sender&& sender, Env&& env) const noexcept {
+        auto&& scheduler{sender.template get<1>()};
+        return ::beman::execution::detail::join_env(::beman::execution::detail::sched_env(scheduler),
+                                                    ::beman::execution::detail::fwd_env(env));
+    }
+    template <::beman::execution::detail::sender_for<::beman::execution::detail::starts_on_t> Sender, typename... Env>
+    auto transform_sender(Sender&& sender, Env&&...) const noexcept {
+        auto&& scheduler{sender.template get<1>()};
+        auto&& new_sender{sender.template get<2>()};
+        return ::beman::execution::let_value(
+            ::beman::execution::schedule(scheduler),
+            [new_sender = ::beman::execution::detail::forward_like<Sender>(new_sender)]() mutable noexcept(
+                ::std::is_nothrow_constructible_v<::std::decay_t<Sender>>) { return ::std::move(new_sender); });
+    }
+#line 44 "include/beman/execution/detail/starts_on.hpp"
+    template <::beman::execution::scheduler Scheduler, ::beman::execution::sender Sender>
+    auto operator()(Scheduler&& scheduler, Sender&& sender) const {
+        auto domain{::beman::execution::detail::query_with_default(
+            ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{})};
+        return ::beman::execution::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(
+                *this, ::std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
+    }
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using starts_on_t = ::beman::execution::detail::starts_on_t;
+export /* --------- */ inline constexpr ::beman::execution::detail::starts_on_t starts_on{};
+} // namespace beman::execution
+
+#line 22 "include/beman/execution/detail/when_all_with_variant.hpp"
+namespace beman::execution::detail {
+struct when_all_with_variant_t {
+
+    template <::beman::execution::sender Sender>
+    auto transform_sender(Sender&& sender, auto&&...) const noexcept {
+        return ::std::forward<Sender>(sender).apply([](auto&&, auto&&, auto&&... child) {
+            return ::beman::execution::when_all(
+                ::beman::execution::into_variant(::beman::execution::detail::forward_like<Sender>(child))...);
+        });
+    }
+#line 33 "include/beman/execution/detail/when_all_with_variant.hpp"
+    template <::beman::execution::sender... Sender>
+    auto operator()(Sender&&... sender) const {
+        using domain_t =
+            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
+        return ::beman::execution::transform_sender(
+            domain_t{}, ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)...));
+    }
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using when_all_with_variant_t = ::beman::execution::detail::when_all_with_variant_t;
+export /* --------- */ inline constexpr ::beman::execution::when_all_with_variant_t when_all_with_variant{};
+} // namespace beman::execution
+
+#line 14 "include/beman/execution/detail/with_awaitable_senders.hpp"
+namespace beman::execution {
+export /* --------- */ template <::beman::execution::detail::class_type Promise>
+struct with_awaitable_senders {
+    template <class OtherPromise>
+        requires(!::std::same_as<OtherPromise, void>)
+    void set_continuation(::std::coroutine_handle<OtherPromise> h) noexcept {
+        contination_ = h;
+        if constexpr (requires(OtherPromise& other) { other.unhandled_stopped(); }) {
+            stopped_handler_ = [](void* p) noexcept -> ::std::coroutine_handle<> {
+                return ::std::coroutine_handle<OtherPromise>::from_address(p).promise().unhandled_stopped();
+            };
+        } else {
+            stopped_handler_ = &default_unhandled_stopped;
+        }
+    }
+#line 30 "include/beman/execution/detail/with_awaitable_senders.hpp"
+    ::std::coroutine_handle<> continuation() const noexcept { return contination_; }
+
+    ::std::coroutine_handle<> unhandled_stopped() noexcept { return stopped_handler_(contination_.address()); }
+
+    template <class Value>
+    auto await_transform(Value&& value)
+        -> ::beman::execution::detail::call_result_t<::beman::execution::as_awaitable_t, Value, Promise&> {
+        return ::beman::execution::as_awaitable(::std::forward<Value>(value), static_cast<Promise&>(*this));
+    }
+#line 40 "include/beman/execution/detail/with_awaitable_senders.hpp"
+  private:
+    friend Promise;
+    with_awaitable_senders() = default;
+
+    [[noreturn]] static auto default_unhandled_stopped(void*) noexcept -> ::std::coroutine_handle<> {
+        ::std::terminate();
+    }
+#line 48 "include/beman/execution/detail/with_awaitable_senders.hpp"
+    ::std::coroutine_handle<> contination_{};
+    ::std::coroutine_handle<> (*stopped_handler_)(void*) noexcept = &default_unhandled_stopped;
+};
+
+} // namespace beman::execution
+
+#line 19 "include/beman/execution/detail/counting_scope.hpp"
+namespace beman::execution {
+export /* --------- */ class counting_scope;
+}
+#line 25 "include/beman/execution/detail/counting_scope.hpp"
+class beman::execution::counting_scope : public ::beman::execution::detail::counting_scope_base {
+  public:
+    class token;
+
+    auto join() noexcept -> ::beman::execution::sender auto {
+        return ::beman::execution::detail::counting_scope_join(this);
+    }
+    auto get_token() noexcept -> token;
+    auto request_stop() noexcept -> void { this->stop_source.request_stop(); }
+
+  private:
+    ::beman::execution::inplace_stop_source stop_source{};
+};
+
+#line 41 "include/beman/execution/detail/counting_scope.hpp"
+class beman::execution::counting_scope::token : public ::beman::execution::detail::counting_scope_base::token {
+  public:
+    template <::beman::execution::sender Sender>
+    auto wrap(Sender&& sender) const noexcept -> ::beman::execution::sender auto {
+        return ::beman::execution::detail::stop_when(
+            ::std::forward<Sender>(sender),
+            static_cast<::beman::execution::counting_scope*>(this->scope)->stop_source.get_token());
+    }
+#line 50 "include/beman/execution/detail/counting_scope.hpp"
+  private:
+    friend class beman::execution::counting_scope;
+    explicit token(::beman::execution::counting_scope* s)
+        : ::beman::execution::detail::counting_scope_base::token(s) {}
+};
+static_assert(::beman::execution::scope_token<::beman::execution::counting_scope::token>);
+
+#line 59 "include/beman/execution/detail/counting_scope.hpp"
+inline auto beman::execution::counting_scope::get_token() noexcept -> beman::execution::counting_scope::token {
+    return beman::execution::counting_scope::token(this);
+}
+#line 16 "include/beman/execution/detail/simple_counting_scope.hpp"
+namespace beman::execution {
+export /* --------- */ class simple_counting_scope;
+}
+#line 22 "include/beman/execution/detail/simple_counting_scope.hpp"
+class beman::execution::simple_counting_scope : public ::beman::execution::detail::counting_scope_base {
+  public:
+    class token;
+
+    auto get_token() noexcept -> token;
+    auto join() noexcept -> ::beman::execution::sender auto {
+        return ::beman::execution::detail::counting_scope_join(this);
+    }
+};
+
+#line 34 "include/beman/execution/detail/simple_counting_scope.hpp"
+class beman::execution::simple_counting_scope::token : public ::beman::execution::detail::counting_scope_base::token {
+  public:
+    template <::beman::execution::sender Sender>
+    auto wrap(Sender&& sender) const noexcept -> Sender&& {
+        return ::std::forward<Sender>(sender);
+    }
+#line 41 "include/beman/execution/detail/simple_counting_scope.hpp"
+  private:
+    friend class beman::execution::simple_counting_scope;
+    explicit token(::beman::execution::detail::counting_scope_base* s)
+        : ::beman::execution::detail::counting_scope_base::token(s) {}
+};
+
+#line 49 "include/beman/execution/detail/simple_counting_scope.hpp"
+inline auto beman::execution::simple_counting_scope::get_token() noexcept
+    -> beman::execution::simple_counting_scope::token {
+    return beman::execution::simple_counting_scope::token(this);
+}
+#line 44 "include/beman/execution/detail/spawn_future.hpp"
+namespace beman::execution::detail {
+template <typename>
+struct non_throwing_args_copy;
+template <typename Rc, typename... A>
+struct non_throwing_args_copy<Rc(A...)> {
+    static constexpr bool value = (true && ... && ::std::is_nothrow_constructible_v<::std::decay_t<A>, A>);
+};
+template <typename S>
+inline constexpr bool non_throwing_args_copy_v{non_throwing_args_copy<S>::value};
+
+template <typename Completions>
+struct spawn_future_state_base;
+template <typename... Sigs>
+struct spawn_future_state_base<::beman::execution::completion_signatures<Sigs...>> {
+    static constexpr bool has_non_throwing_args_copy = (true && ... && non_throwing_args_copy_v<Sigs>);
+    using result_t                                   = ::beman::execution::detail::meta::unique<
+                                          ::std::conditional_t<has_non_throwing_args_copy,
+                                                               ::std::variant<::std::monostate, ::beman::execution::detail::as_tuple_t<Sigs>...>,
+                                                               ::std::variant<::std::monostate,
+                                                                              ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>,
+                                                                              ::beman::execution::detail::as_tuple_t<Sigs>...>>>;
+
+    result_t result{};
+    virtual ~spawn_future_state_base()       = default;
+    virtual auto complete() noexcept -> void = 0;
+};
+
+template <typename Completions>
+struct spawn_future_receiver {
+    using receiver_concept = ::beman::execution::receiver_t;
+    using state_t          = ::beman::execution::detail::spawn_future_state_base<Completions>;
+
+    state_t* state{};
+
+    template <typename... A>
+    auto set_value(A&&... a) && noexcept -> void {
+        this->set_complete<::beman::execution::set_value_t>(::std::forward<A>(a)...);
+    }
+    template <typename E>
+    auto set_error(E&& e) && noexcept -> void {
+        this->set_complete<::beman::execution::set_error_t>(::std::forward<E>(e));
+    }
+    auto set_stopped() && noexcept -> void { this->set_complete<::beman::execution::set_stopped_t>(); }
+
+    template <typename Tag, typename... T>
+    auto set_complete(T&&... t) noexcept {
+        try {
+            this->state->result.template emplace<::beman::execution::detail::decayed_tuple<Tag, T...>>(
+                Tag(), ::std::forward<T>(t)...);
+        } catch (...) {
+            if constexpr (!state_t::has_non_throwing_args_copy) {
+                this->state->result
+                    .template emplace<::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>>(
+                        ::beman::execution::set_error_t{}, ::std::current_exception());
+            }
+        }
+        this->state->complete();
+    }
+};
+
+template <::beman::execution::sender Sndr, typename Env>
+using future_spawned_sender = decltype(::beman::execution::write_env(
+    ::beman::execution::detail::stop_when(::std::declval<Sndr>(),
+                                          ::std::declval<::beman::execution::inplace_stop_token>()),
+    ::std::declval<Env>()));
+
+template <::beman::execution::sender Sndr, typename Env>
+using spawn_future_sigs = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
+    ::beman::execution::set_stopped_t(),
+    ::beman::execution::completion_signatures_of_t<::beman::execution::detail::future_spawned_sender<Sndr, Env>>>>;
+
+template <typename Allocator, ::beman::execution::scope_token Token, ::beman::execution::sender Sndr, typename Env>
+struct spawn_future_state
+    : ::beman::execution::detail::spawn_future_state_base<::beman::execution::detail::spawn_future_sigs<Sndr, Env>> {
+    using alloc_t          = typename ::std::allocator_traits<Allocator>::template rebind_alloc<spawn_future_state>;
+    using traits_t         = ::std::allocator_traits<alloc_t>;
+    using spawned_sender_t = ::beman::execution::detail::future_spawned_sender<Sndr, Env>;
+    using sigs_t           = ::beman::execution::detail::spawn_future_sigs<Sndr, Env>;
+    using receiver_t       = ::beman::execution::detail::spawn_future_receiver<sigs_t>;
+    static_assert(::beman::execution::sender<spawned_sender_t>);
+    static_assert(::beman::execution::receiver<receiver_t>);
+    using op_t = ::beman::execution::connect_result_t<spawned_sender_t, receiver_t>;
+
+    template <::beman::execution::sender S>
+    spawn_future_state(auto a, S&& s, Token tok, Env env)
+        : alloc(::std::move(a)),
+          op(::beman::execution::write_env(
+                 ::beman::execution::detail::stop_when(::std::forward<S>(s), source.get_token()), env),
+             receiver_t{this}),
+          token(::std::move(tok)),
+          associated(token.try_associate()) {
+        if (this->associated) {
+            ::beman::execution::start(this->op);
+        } else {
+            ::beman::execution::set_stopped(receiver_t{this});
+        }
+    }
+    auto complete() noexcept -> void override {
+        {
+            ::std::lock_guard cerberos(this->gate);
+            if (this->fun == nullptr) {
+                this->receiver = this;
+                return;
+            }
+        }
+        this->fun(this->receiver, *this);
+    }
+    auto abandon() noexcept -> void {
+        bool ready{[&] {
+            ::std::lock_guard cerberos(this->gate);
+            if (this->receiver == nullptr) {
+                this->receiver = this;
+                this->fun      = [](void*, spawn_future_state& state) noexcept { state.destroy(); };
+                return false;
+            }
+            return true;
+        }()};
+        if (ready) {
+            this->destroy();
+        } else {
+            this->source.request_stop();
+        }
+    }
+    template <::beman::execution::receiver Rcvr>
+    static auto complete_receiver(Rcvr& rcvr, typename spawn_future_state::result_t& res) noexcept {
+        std::visit(
+            [&rcvr]<typename Tuplish>(Tuplish&& tuplish) noexcept {
+                if constexpr (!::std::same_as<::std::remove_cvref_t<decltype(tuplish)>, ::std::monostate>) {
+                    ::std::apply(
+                        [&rcvr]<typename... Args>(auto cpo, Args&&... args) {
+                            cpo(::std::move(rcvr), ::std::forward<Args>(args)...);
+                        },
+                        ::std::forward<Tuplish>(tuplish));
+                }
+            },
+            ::std::move(res));
+    }
+    template <::beman::execution::receiver Rcvr>
+    auto consume(Rcvr& rcvr) noexcept -> void {
+        {
+            ::std::lock_guard cerberos(this->gate);
+            if (this->receiver == nullptr) {
+                this->receiver = &rcvr;
+                this->fun      = [](void* ptr, spawn_future_state& state) noexcept {
+                    spawn_future_state::complete_receiver(*static_cast<Rcvr*>(ptr), state.result);
+                };
+                return;
+            }
+        }
+        spawn_future_state::complete_receiver(rcvr, this->result);
+    }
+    auto destroy() noexcept -> void {
+        Token tok{this->token};
+        bool  assoc{this->associated};
+        {
+            alloc_t a{this->alloc};
+            traits_t::destroy(a, this);
+            traits_t::deallocate(a, this, 1u);
+        }
+        if (assoc) {
+            tok.disassociate();
+        }
+    }
+#line 208 "include/beman/execution/detail/spawn_future.hpp"
+    ::std::mutex                            gate{};
+    alloc_t                                 alloc;
+    ::beman::execution::inplace_stop_source source{};
+    op_t                                    op;
+    Token                                   token;
+    bool                                    associated{false};
+    void*                                   receiver{};
+    auto (*fun)(void*, spawn_future_state&) noexcept -> void = nullptr;
+};
+
+class spawn_future_t {
+  public:
+    template <::beman::execution::sender Sndr, ::beman::execution::scope_token Tok, typename Ev>
+        requires ::beman::execution::detail::queryable<::std::remove_cvref_t<Ev>>
+    auto operator()(Sndr&& sndr, Tok&& tok, Ev&& ev) const {
+
+        auto make{[&]() -> decltype(auto) { return tok.wrap(::std::forward<Sndr>(sndr)); }};
+        using sndr_t = decltype(make());
+        static_assert(::beman::execution::sender<Sndr>);
+
+        auto [alloc, senv] = spawn_get_allocator(sndr, ev);
+        using state_t = ::beman::execution::detail::spawn_future_state<decltype(alloc), Tok, sndr_t, decltype(senv)>;
+        using state_alloc_t  = typename ::std::allocator_traits<decltype(alloc)>::template rebind_alloc<state_t>;
+        using state_traits_t = ::std::allocator_traits<state_alloc_t>;
+        state_alloc_t state_alloc(alloc);
+        state_t*      op{state_traits_t::allocate(state_alloc, 1u)};
+        try {
+            state_traits_t::construct(state_alloc, op, alloc, make(), tok, senv);
+        } catch (...) {
+            state_traits_t::deallocate(state_alloc, op, 1u);
+            throw;
+        }
+#line 241 "include/beman/execution/detail/spawn_future.hpp"
+        using deleter = decltype([](state_t* p) noexcept { p->abandon(); });
+        return ::beman::execution::detail::make_sender(*this, ::std::unique_ptr<state_t, deleter>{op});
+    }
+    template <::beman::execution::sender Sndr, ::beman::execution::scope_token Tok>
+    auto operator()(Sndr&& sndr, Tok&& tok) const {
+        return (*this)(::std::forward<Sndr>(sndr), ::std::forward<Tok>(tok), ::beman::execution::env<>{});
+    }
+};
+
+template <typename State, typename Deleter, typename Env>
+struct completion_signatures_for_impl<
+    ::beman::execution::detail::basic_sender<::beman::execution::detail::spawn_future_t,
+                                             ::std::unique_ptr<State, Deleter>>,
+    Env> {
+    using type = typename State::sigs_t;
+};
+
+template <>
+struct impls_for<spawn_future_t> : ::beman::execution::detail::default_impls {
+    static constexpr auto start{[](auto& state, auto& rcvr) noexcept -> void { state->consume(rcvr); }};
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using spawn_future_t = ::beman::execution::detail::spawn_future_t;
+export /* --------- */ inline constexpr spawn_future_t spawn_future{};
+} // namespace beman::execution
+
+#line 22 "include/beman/execution/detail/spawn.hpp"
+namespace beman::execution::detail {
+struct spawn_t {
+    struct state_base {
+        virtual ~state_base()                    = default;
+        virtual auto complete() noexcept -> void = 0;
+    };
+
+    struct receiver {
+        using receiver_concept = ::beman::execution::receiver_t;
+        state_base* state{};
+
+        auto set_value() && noexcept -> void { this->state->complete(); }
+        auto set_stopped() && noexcept -> void { this->state->complete(); }
+    };
+
+    template <typename Alloc, ::beman::execution::scope_token Tok, ::beman::execution::sender Sndr>
+    struct state : state_base {
+        using op_t     = ::beman::execution::connect_result_t<Sndr, receiver>;
+        using alloc_t  = typename ::std::allocator_traits<Alloc>::template rebind_alloc<state>;
+        using traits_t = ::std::allocator_traits<alloc_t>;
+
+        state(Alloc a, Sndr&& sndr, Tok tok)
+            : alloc(a), op(::beman::execution::connect(::std::forward<Sndr>(sndr), receiver{this})), token(tok) {
+            if (this->token.try_associate()) {
+                ::beman::execution::start(this->op);
+            } else {
+                this->destroy();
+            }
+        }
+        auto complete() noexcept -> void override {
+            Tok tok(this->token);
+            this->destroy();
+            tok.disassociate();
+        }
+        auto destroy() noexcept -> void {
+            alloc_t all(this->alloc);
+            traits_t::destroy(all, this);
+            traits_t::deallocate(all, this, 1);
+        }
+#line 62 "include/beman/execution/detail/spawn.hpp"
+        alloc_t alloc;
+        op_t    op;
+        Tok     token;
+    };
+
+    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token, typename Env>
+    auto operator()(Sender&& sender, Token&& tok, Env&& env) const {
+        auto new_sender{tok.wrap(::std::forward<Sender>(sender))};
+        auto [all, senv] = ::beman::execution::detail::spawn_get_allocator(new_sender, env);
+
+        using sender_t = decltype(::beman::execution::write_env(::std::move(new_sender), senv));
+        using state_t  = state<decltype(all), Token, sender_t>;
+        using alloc_t  = typename ::std::allocator_traits<decltype(all)>::template rebind_alloc<state_t>;
+        using traits_t = ::std::allocator_traits<alloc_t>;
+        alloc_t  alloc(all);
+        state_t* op{traits_t::allocate(alloc, 1u)};
+        traits_t::construct(alloc, op, all, ::beman::execution::write_env(::std::move(new_sender), senv), tok);
+    }
+    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token>
+    auto operator()(Sender&& sender, Token&& token) const {
+        return (*this)(::std::forward<Sender>(sender), ::std::forward<Token>(token), ::beman::execution::env<>{});
+    }
+};
+} // namespace beman::execution::detail
+
+namespace beman::execution {
+export /* --------- */ using spawn_t = ::beman::execution::detail::spawn_t;
+export /* --------- */ inline constexpr spawn_t spawn{};
+} // namespace beman::execution
+
+#line 32 "include/beman/execution/detail/on.hpp"
+namespace beman::execution::detail {
+struct on_t : ::beman::execution::sender_adaptor_closure<on_t> {
+    template <::beman::execution::detail::sender_for<on_t> OutSndr, typename Env>
+    auto transform_env(OutSndr&& out_sndr, Env&& env) const -> decltype(auto) {
+        auto&& data{out_sndr.template get<1>()};
+
+        if constexpr (::beman::execution::scheduler<decltype(data)>)
+            return ::beman::execution::detail::join_env(
+                ::beman::execution::detail::sched_env(::beman::execution::detail::forward_like<OutSndr>(data)
+
+                                                          ),
+                ::beman::execution::detail::fwd_env(::std::forward<Env>(env)));
+        else
+            return std::forward<Env>(env);
+    }
+#line 48 "include/beman/execution/detail/on.hpp"
+    template <typename>
+    struct env_needs_get_scheduler {
+        using sender_concept = ::beman::execution::sender_t;
+        template <typename Env>
+        auto get_completion_signatures(Env&&) const {
+            return env_needs_get_scheduler<Env>{};
+        }
+    };
+
+    template <::beman::execution::detail::sender_for<on_t> OutSndr, typename Env>
+    auto transform_sender(OutSndr&& out_sndr, Env&& env) const -> decltype(auto) {
+        struct not_a_scheduler {};
+        auto&& [_, data, child] = out_sndr;
+
+        if constexpr (::beman::execution::scheduler<decltype(data)>) {
+            auto sch{::beman::execution::detail::query_with_default(
+                ::beman::execution::get_scheduler, env, not_a_scheduler{})};
+            if constexpr (::std::same_as<not_a_scheduler, decltype(sch)>) {
+                return env_needs_get_scheduler<Env>{};
+            } else {
+                return ::beman::execution::continues_on(
+                    ::beman::execution::starts_on(::beman::execution::detail::forward_like<OutSndr>(data),
+                                                  ::beman::execution::detail::forward_like<OutSndr>(child)),
+                    ::std::move(sch));
+            }
+        } else {
+            auto& [sch, closure] = data;
+            auto orig_sch{::beman::execution::detail::query_with_default(
+                ::beman::execution::get_completion_scheduler<::beman::execution::set_value_t>,
+                ::beman::execution::get_env(child),
+                ::beman::execution::detail::query_with_default(
+                    ::beman::execution::get_scheduler, env, not_a_scheduler{}))};
+
+            if constexpr (::std::same_as<not_a_scheduler, decltype(orig_sch)>) {
+                return env_needs_get_scheduler<Env>{};
+            } else {
+                return ::beman::execution::detail::write_env(
+                    ::beman::execution::continues_on(
+                        ::beman::execution::detail::forward_like<OutSndr>(closure)(::beman::execution::continues_on(
+                            ::beman::execution::detail::write_env(
+                                ::beman::execution::detail::forward_like<OutSndr>(child),
+                                ::beman::execution::detail::sched_env(orig_sch)),
+                            sch)),
+                        orig_sch),
+                    ::beman::execution::detail::sched_env(env));
+            }
+        }
+    }
+#line 97 "include/beman/execution/detail/on.hpp"
+    template <::beman::execution::scheduler Sch, ::beman::execution::sender Sndr>
+        requires ::beman::execution::detail::is_sender_adaptor_closure<Sndr>
+    auto operator()(Sch&&, Sndr&&) const -> void =
+        BEMAN_EXECUTION_DELETE("on(sch, sndr) requires that sndr isn't both a sender and sender adaptor closure");
+
+    template <::beman::execution::scheduler                         Sch,
+              ::beman::execution::sender                            Sndr,
+              ::beman::execution::detail::is_sender_adaptor_closure Closure>
+        requires ::beman::execution::detail::is_sender_adaptor_closure<Sndr>
+    auto operator()(Sndr&&, Sch&&, Closure&&) const -> void =
+        BEMAN_EXECUTION_DELETE("on(sch, sndr) requires that sndr isn't both a sender and sender adaptor closure");
+
+    template <::beman::execution::scheduler Sch, ::beman::execution::sender Sndr>
+    auto operator()(Sch&& sch, Sndr&& sndr) const {
+        auto domain{::beman::execution::detail::query_with_default(
+            ::beman::execution::get_domain, sch, ::beman::execution::default_domain{})};
+        return ::beman::execution::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(*this, ::std::forward<Sch>(sch), ::std::forward<Sndr>(sndr)));
+    }
+    template <::beman::execution::scheduler                         Sch,
+              ::beman::execution::sender                            Sndr,
+              ::beman::execution::detail::is_sender_adaptor_closure Closure>
+    auto operator()(Sndr&& sndr, Sch&& sch, Closure&& closure) const {
+        auto domain{::beman::execution::detail::get_domain_early(sndr)};
+        return ::beman::execution::transform_sender(
+            domain,
+            ::beman::execution::detail::make_sender(
+                *this,
+                ::beman::execution::detail::product_type{::std::forward<Sch>(sch), ::std::forward<Closure>(closure)},
+                ::std::forward<Sndr>(sndr)));
+    }
+    template <::beman::execution::scheduler Sch, ::beman::execution::detail::is_sender_adaptor_closure Closure>
+    auto operator()(Sch&& sch, Closure&& closure) const {
+        return ::beman::execution::detail::sender_adaptor{
+            *this, ::std::forward<Sch>(sch), ::std::forward<Closure>(closure)};
+    }
+};
 
-// [exec.queries], queries
-export using ::beman::execution::forwarding_query_t;
-export using ::beman::execution::get_allocator_t;
-export using ::beman::execution::get_stop_token_t;
-
-export using ::beman::execution::forwarding_query;
-export using ::beman::execution::get_allocator;
-export using ::beman::execution::get_stop_token;
-
-export using ::beman::execution::stop_token_of_t;
-
-export using ::beman::execution::get_domain_t;
-export using ::beman::execution::get_scheduler_t;
-export using ::beman::execution::get_delegation_scheduler_t;
-//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee_t;
-export using ::beman::execution::get_completion_scheduler_t;
-
-export using ::beman::execution::get_domain;
-export using ::beman::execution::get_scheduler;
-export using ::beman::execution::get_delegation_scheduler;
-//-dk:TODO export using ::beman::execution::forward_progress_guarantee;
-//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee;
-export using ::beman::execution::get_completion_scheduler;
-
-export using ::beman::execution::env;
-export using ::beman::execution::get_env_t;
-export using ::beman::execution::get_env;
-
-export using ::beman::execution::env_of_t;
-
-// [exec.domain.default], execution_domains
-export using ::beman::execution::default_domain;
-
-// [exec.sched], schedulers
-export using ::beman::execution::scheduler_t;
-export using ::beman::execution::scheduler;
-
-// [exec.recv], receivers
-export using ::beman::execution::receiver_t;
-export using ::beman::execution::receiver;
-export using ::beman::execution::receiver_of;
-
-export using ::beman::execution::set_value_t;
-export using ::beman::execution::set_error_t;
-export using ::beman::execution::set_stopped_t;
-
-export using ::beman::execution::set_value;
-export using ::beman::execution::set_error;
-export using ::beman::execution::set_stopped;
-
-// [exec.opstate], operation states
-export using ::beman::execution::operation_state_t;
-export using ::beman::execution::operation_state;
-export using ::beman::execution::start_t;
-export using ::beman::execution::start;
-
-// [exec.snd], senders
-export using ::beman::execution::sender_t;
-export using ::beman::execution::sender;
-export using ::beman::execution::sender_in;
-//-dk:TODO export using ::beman::execution::sender_to;
-
-// [exec.getcomplsigs], completion signatures
-export using ::beman::execution::get_completion_signatures_t;
-export using ::beman::execution::get_completion_signatures;
-export using ::beman::execution::completion_signatures_of_t;
-export using ::beman::execution::value_types_of_t;
-export using ::beman::execution::error_types_of_t;
-export using ::beman::execution::sends_stopped;
-export using ::beman::execution::tag_of_t;
-
-// [exec.snd.transform], sender transformations
-export using ::beman::execution::transform_sender;
-
-// [exec.snd.transform.env], environment transformations
-//-dk:TODO export using ::beman::execution::transform_env;
-
-// [exec.snd.apply], sender algorithm application
-export using ::beman::execution::apply_sender;
-
-// [exec.connect], the connect sender algorithm
-export using ::beman::execution::connect_t;
-export using ::beman::execution::connect;
-export using ::beman::execution::connect_result_t;
-
-// [exec.factories], sender factories
-export using ::beman::execution::just_t;
-export using ::beman::execution::just_error_t;
-export using ::beman::execution::just_stopped_t;
-export using ::beman::execution::schedule_t;
-
-export using ::beman::execution::just;
-export using ::beman::execution::just_error;
-export using ::beman::execution::just_stopped;
-export using ::beman::execution::schedule;
-export using ::beman::execution::read_env;
-
-export using ::beman::execution::schedule_result_t;
-
-// [exec.adapt], sender adaptors
-export using ::beman::execution::sender_adaptor_closure;
-
-export using ::beman::execution::starts_on_t;
-export using ::beman::execution::continues_on_t;
-export using ::beman::execution::on_t;
-export using ::beman::execution::schedule_from_t;
-export using ::beman::execution::then_t;
-export using ::beman::execution::upon_error_t;
-export using ::beman::execution::upon_stopped_t;
-export using ::beman::execution::let_value_t;
-export using ::beman::execution::let_error_t;
-export using ::beman::execution::let_stopped_t;
-export using ::beman::execution::bulk_t;
-export using ::beman::execution::split_t;
-export using ::beman::execution::when_all_t;
-export using ::beman::execution::when_all_with_variant_t;
-export using ::beman::execution::into_variant_t;
-//-dk:TODO export using ::beman::execution::stopped_as_optional_t;
-//-dk:TODO export using ::beman::execution::stopped_as_error_t;
-
-export using ::beman::execution::starts_on;
-export using ::beman::execution::continues_on;
-export using ::beman::execution::on;
-export using ::beman::execution::schedule_from;
-export using ::beman::execution::then;
-export using ::beman::execution::upon_error;
-export using ::beman::execution::upon_stopped;
-export using ::beman::execution::let_value;
-export using ::beman::execution::let_error;
-export using ::beman::execution::let_stopped;
-export using ::beman::execution::bulk;
-export using ::beman::execution::split;
-export using ::beman::execution::when_all;
-export using ::beman::execution::when_all_with_variant;
-export using ::beman::execution::into_variant;
-//-dk:TODO export using ::beman::execution::stopped_as_optional;
-//-dk:TODO export using ::beman::execution::stopped_as_error;
-
-// [exec.util.cmplsig]
-export using ::beman::execution::completion_signatures;
-
-// [exec.util.cmplsig.trans]
-//-dk:TODO export using ::beman::execution::transform_completion_signatures;
-//-dk:TODO export using ::beman::execution::transform_completion_signatures_of;
-
-// [exec.run.loop], run_loop
-export using ::beman::execution::run_loop;
-
-// [exec.consumers], consumers
-export using ::beman::execution::sync_wait_t;
-//-dk:TODO export using ::beman::execution::sync_wait_with_variant_t;
-
-export using ::beman::execution::sync_wait;
-//-dk:TODO export using ::beman::execution::sync_wait_with_variant;
-
-// [exec.as.awaitable]
-export using ::beman::execution::as_awaitable_t;
-export using ::beman::execution::as_awaitable;
-
-// [exec.with.awaitable.senders]
-export using ::beman::execution::with_awaitable_senders;
-
-//-dk:TODO add section
-export using ::beman::execution::prop;
-export using ::beman::execution::write_env_t;
-export using ::beman::execution::write_env;
-export using ::beman::execution::affine_on_t;
-export using ::beman::execution::affine_on;
-export using ::beman::execution::read_env_t;
-export using ::beman::execution::read_env;
-export using ::beman::execution::simple_counting_scope;
-export using ::beman::execution::counting_scope;
-export using ::beman::execution::scope_token;
-
-namespace detail {
-export using ::beman::execution::detail::env_promise;
-export using ::beman::execution::detail::await_result_type;
-export using ::beman::execution::detail::simple_allocator;
-export using ::beman::execution::detail::sync_wait_env;
-export using ::beman::execution::detail::sync_wait_result_type;
-export using ::beman::execution::detail::sync_wait_state;
-export using ::beman::execution::detail::sync_wait_receiver;
-} // namespace detail
+} // namespace beman::execution::detail
 
+namespace beman::execution {
+export /* --------- */ using on_t = ::beman::execution::detail::on_t;
+export /* --------- */ inline constexpr ::beman::execution::on_t on{};
 } // namespace beman::execution
diff --git a/tests/beman/execution/CMakeLists.txt b/tests/beman/execution/CMakeLists.txt
index 9fdbbcdb..65238e5c 100644
--- a/tests/beman/execution/CMakeLists.txt
+++ b/tests/beman/execution/CMakeLists.txt
@@ -107,7 +107,6 @@ list(
     thread.test
     utilities.test
 )
-# set(execution_tests exec-then.test)
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/include)
 
diff --git a/tests/beman/execution/exec-affine-on.test.cpp b/tests/beman/execution/exec-affine-on.test.cpp
index a5f9f338..77ed9f13 100644
--- a/tests/beman/execution/exec-affine-on.test.cpp
+++ b/tests/beman/execution/exec-affine-on.test.cpp
@@ -5,6 +5,7 @@
 #include <condition_variable>
 #include <mutex>
 #include <thread>
+#include <tuple>
 #ifdef BEMAN_HAS_MODULES
 import beman.execution;
 #else

From 689c0859c9ed36000e747251a652e799419d7e25 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Thu, 5 Feb 2026 01:18:04 +0000
Subject: [PATCH 4/9] bringing the section to somewhat of an end

---
 docs/modules.md | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/docs/modules.md b/docs/modules.md
index ea872815..dbf7b442 100644
--- a/docs/modules.md
+++ b/docs/modules.md
@@ -126,7 +126,7 @@ compilers:
   is, all headers really need to be included before the name
   declaration. That is pretty much _not_ how the components in
   [`beman.execution`](https://github.com/bemanproject/execution) are
-  orgnaized.
+  organized.
   </li>
 </ol>
 
@@ -176,6 +176,41 @@ of silly errors in the component headers which could be quickly
 resolved, though. That wasn't quite as true for the test files,
 though (more [ruminations on tests](#modules-vs-testing) below):
 
+- Many tests didn't include all standard library headers they
+  dependent on. Since the corresponding header were actually included
+  by a component header things still worked. So, the corresponding
+  headers needed to be added.
+- Instead of `#include <beman/execution/execution.hpp>` the tests
+  now use `import beman.execution;` (well, the test really use
+  conditional compilation to either use a header or an `import`
+  statement). Including any standard library header _after_ the
+  `import` statement again confuses the compiler, i.e., some
+  reordering in the files was needed: the test files deliberately
+  included the component's header first (to make sure all needed
+  headers are included by the component header) but this include
+  statement is now replaced by the `import` statement.
+- The tests actually use some of the implementation-defined entities
+  which were not meant to be `export`ed. To still have these tests
+  I ended up `export`ing the necessary implementation-defined names.
+  That needs to be corrected eventually (assuming that is actually
+  possible which isn't quite as clear).
+- Of course, the tests actually used the various names and it turned
+  out that quite a few names, e.g., the `operator|`, were missing.
+
+That worked OK with one compiler. Then I tried a different compiler
+and lots of issues emerged:
+
+- More names needed to be `export`ed for the tests.
+- Some things just didn't compile at all and needed to be changed
+  (I managed to avoid the problems but I haven't quite understood why).
+- Symbols were undefined.
+
+I ended up spending quite a bit of time reshuffling where headers
+go, fixing some actual bugs, and working around what looks like
+compiler problems. Most of that was, however, fairly mechanical
+and eventually I got a `module` declaration working with all major
+C++ compilers (using recent versions of each).
+
 -dk:TODO `export using`
 -dk:TODO `import std;`
 

From 2fab9bd8440dce7847f9e758a35ec9ca718f435f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Thu, 5 Feb 2026 23:16:32 +0000
Subject: [PATCH 5/9] fixed a bunch of things and created a first draft of
 module blog

---
 .codespellignore                              |    1 +
 docs/modules.md                               |  178 +-
 examples/CMakeLists.txt                       |    2 +-
 examples/modules-and-header.cpp               |   11 +
 include/beman/execution/detail/affine_on.hpp  |    4 +-
 .../beman/execution/detail/apply_sender.hpp   |    4 +-
 .../beman/execution/detail/as_awaitable.hpp   |    4 +-
 include/beman/execution/detail/associate.hpp  |   10 +-
 .../execution/detail/await_result_type.hpp    |    2 +-
 .../execution/detail/basic_operation.hpp      |    2 +-
 .../beman/execution/detail/basic_state.hpp    |    2 +-
 include/beman/execution/detail/bulk.hpp       |    4 +-
 include/beman/execution/detail/common.hpp     |    4 -
 .../detail/completion_signatures.hpp          |    2 +-
 .../detail/completion_signatures_of_t.hpp     |    2 +-
 include/beman/execution/detail/connect.hpp    |    6 +-
 .../beman/execution/detail/connect_all.hpp    |    2 +-
 .../execution/detail/connect_result_t.hpp     |    2 +-
 .../beman/execution/detail/continues_on.hpp   |    4 +-
 .../beman/execution/detail/counting_scope.hpp |    2 +-
 .../beman/execution/detail/default_domain.hpp |    2 +-
 include/beman/execution/detail/env.hpp        |    2 +-
 include/beman/execution/detail/env_of_t.hpp   |    2 +-
 .../beman/execution/detail/env_promise.hpp    |    2 +-
 .../execution/detail/error_types_of_t.hpp     |    6 +-
 .../execution/detail/forwarding_query.hpp     |    4 +-
 include/beman/execution/detail/fwd_env.hpp    |    2 +-
 .../beman/execution/detail/get_allocator.hpp  |    4 +-
 .../detail/get_completion_scheduler.hpp       |    4 +-
 .../detail/get_completion_signatures.hpp      |    4 +-
 .../detail/get_delegation_scheduler.hpp       |    4 +-
 include/beman/execution/detail/get_domain.hpp |    4 +-
 include/beman/execution/detail/get_env.hpp    |    4 +-
 .../beman/execution/detail/get_scheduler.hpp  |    4 +-
 .../beman/execution/detail/get_stop_token.hpp |    4 +-
 .../beman/execution/detail/indices_for.hpp    |    2 +-
 .../execution/detail/inplace_stop_source.hpp  |    8 +-
 .../beman/execution/detail/into_variant.hpp   |    6 +-
 include/beman/execution/detail/just.hpp       |   12 +-
 include/beman/execution/detail/let.hpp        |   12 +-
 include/beman/execution/detail/make_env.hpp   |    2 +-
 .../execution/detail/never_stop_token.hpp     |    2 +-
 .../beman/execution/detail/nostopstate.hpp    |    4 +-
 include/beman/execution/detail/on.hpp         |    4 +-
 .../execution/detail/operation_state.hpp      |    4 +-
 .../beman/execution/detail/product_type.hpp   |    1 +
 include/beman/execution/detail/prop.hpp       |    2 +-
 include/beman/execution/detail/read_env.hpp   |    4 +-
 include/beman/execution/detail/receiver.hpp   |    4 +-
 .../beman/execution/detail/receiver_of.hpp    |    2 +-
 include/beman/execution/detail/run_loop.hpp   |    2 +-
 include/beman/execution/detail/schedule.hpp   |    4 +-
 .../beman/execution/detail/schedule_from.hpp  |    4 +-
 .../execution/detail/schedule_result_t.hpp    |    2 +-
 include/beman/execution/detail/scheduler.hpp  |    2 +-
 .../beman/execution/detail/scheduler_t.hpp    |    2 +-
 .../beman/execution/detail/scope_token.hpp    |    2 +-
 include/beman/execution/detail/sender.hpp     |    4 +-
 .../beman/execution/detail/sender_adaptor.hpp |    2 +-
 .../detail/sender_adaptor_closure.hpp         |    4 +-
 include/beman/execution/detail/sender_in.hpp  |    2 +-
 .../beman/execution/detail/sends_stopped.hpp  |    2 +-
 include/beman/execution/detail/set_error.hpp  |    4 +-
 .../beman/execution/detail/set_stopped.hpp    |    4 +-
 include/beman/execution/detail/set_value.hpp  |    4 +-
 .../execution/detail/simple_allocator.hpp     |    2 +-
 .../detail/simple_counting_scope.hpp          |    2 +-
 include/beman/execution/detail/spawn.hpp      |    4 +-
 .../beman/execution/detail/spawn_future.hpp   |    4 +-
 include/beman/execution/detail/split.hpp      |    4 +-
 include/beman/execution/detail/start.hpp      |    4 +-
 include/beman/execution/detail/starts_on.hpp  |    4 +-
 .../execution/detail/stop_callback_for_t.hpp  |    2 +-
 .../beman/execution/detail/stop_source.hpp    |    8 +-
 .../execution/detail/stop_token_of_t.hpp      |    2 +-
 .../execution/detail/stoppable_source.hpp     |    2 +-
 .../execution/detail/stoppable_token.hpp      |    2 +-
 include/beman/execution/detail/sync_wait.hpp  |   13 +-
 include/beman/execution/detail/tag_of_t.hpp   |    2 +-
 include/beman/execution/detail/then.hpp       |   12 +-
 .../execution/detail/transform_sender.hpp     |    8 +-
 .../execution/detail/unstoppable_token.hpp    |    2 +-
 .../execution/detail/valid_completion_for.hpp |    2 +-
 .../execution/detail/value_types_of_t.hpp     |    8 +-
 include/beman/execution/detail/when_all.hpp   |    4 +-
 .../detail/when_all_with_variant.hpp          |    4 +-
 .../detail/with_awaitable_senders.hpp         |    2 +-
 include/beman/execution/detail/write_env.hpp  |    4 +-
 src/beman/execution/CMakeLists.txt            |    2 +-
 src/beman/execution/execution-using.cppm      |  258 -
 src/beman/execution/execution.cppm            | 6678 +----------------
 .../execution/exec-scope-counting.test.cpp    |    2 +-
 .../exec-scope-simple-counting.test.cpp       |    2 +-
 .../include/test/inline_scheduler.hpp         |    6 +-
 .../execution/include/test/stop_token.hpp     |    5 +-
 .../execution/stopsource-general.test.cpp     |    5 +-
 .../stopsource-inplace-general.test.cpp       |    3 +-
 .../execution/stoptoken-general.test.cpp      |    3 +-
 tests/beman/execution/stoptoken-mem.test.cpp  |    3 +-
 .../execution/thread-stoptoken-intro.test.cpp |    5 +-
 100 files changed, 591 insertions(+), 6895 deletions(-)
 create mode 100644 examples/modules-and-header.cpp
 delete mode 100644 src/beman/execution/execution-using.cppm

diff --git a/.codespellignore b/.codespellignore
index 2fddd5ed..d7f036c0 100644
--- a/.codespellignore
+++ b/.codespellignore
@@ -3,3 +3,4 @@ copyable
 pullrequest
 snd
 statics
+Claus
diff --git a/docs/modules.md b/docs/modules.md
index dbf7b442..0aefed80 100644
--- a/docs/modules.md
+++ b/docs/modules.md
@@ -71,7 +71,7 @@ immediately. So I abandoned that particular approach, again.
 ### Generate Module Friendly Code: `mk-module.py`
 
 The attempts up to this point had indicated a few things which
-were somewhat misaligned with the way the code in 
+were somewhat misaligned with the way the code in
 [`beman.execution`](https://github.com/bemanproject/execution)
 is laid out. The code is structured into lots of small _components_
 (loosely based on John Lakos's idea of components in his 1996 version
@@ -211,16 +211,178 @@ compiler problems. Most of that was, however, fairly mechanical
 and eventually I got a `module` declaration working with all major
 C++ compilers (using recent versions of each).
 
--dk:TODO `export using`
--dk:TODO `import std;`
+### Retry `export using`
+
+Using a script to generate a `module` file restructured to better
+match the `module` needs did get me a working `module` definition.
+However, that shouldn't really be necessary. While fixing various
+minor bugs I did fix a few things which looked as if they may have
+had an impact when trying to use `export using <name>`. So tried
+that approach again and this time it worked, at least, for some of
+the compilers.  That looked promising!
+
+One compiler put up a fight, though! I'm using the an exposition-only
+`product_type` class template as is described in
+[[exec]](https://eel.is/c++draft/exec#snd.expos-17) and I got a
+compiler error about using <code>std::get&lt;N&gt;(<i>sender</i>)</code>.
+After some experimentation I found that `export`ing the `product_type`
+template and the relevant `tuple_size` and `tuple_element`
+specializations I could resolve this problem, too.
+
+Once I got past that I encountered a problem which is probably quite
+common: following the specificaton of exposition-only `impls_for`
+class template I used lambda functions for the various "overrides".
+One compiler complained about undefined symbols about these! Of
+course, using lambda functions in a header is problematic because
+each instance of a lambda function has a different type, even if
+they are spelled identical! So I replaced all of these lambda functions
+by `struct`s which only have one member which is an `operator()`.
+
+With that I also got a working `module` definition. While I'm quite
+fond of my generator I prefer this approach! There shouldn't be a
+need to rewrite an implementation just to make it a `module`. I
+should also get away not needing any macros to insert/remove the
+`export` keywords from declarations. Instead, the `export`ed names
+are just listed in the module definition file. What is currently
+missing is a bit of a clean-up to remove some of the artifacts.
+Also, there may be more implementation details exported than is
+actually necessary.
+
+### `import std;`
+
+Currently, `import std;` is _not_, yet, used. It should be straight
+forward to conditionally choose between `import std;` and including
+the headers.
 
 ## Changes Needed to Support Modules
 
--dk:TODO order of headers vs. import
--dk:TODO fixes for join_env
--dk:TODO requires declaration of variant, optional, etc.
-
-## Scanning
+When enabling modules I needed to apply quite a few, mostly
+rather simple changes. Some of teh necessary changes did take
+me a bit to actually discover. Here is broadly what I needed
+to change:
+
+- I had slotted and `import beman.execution;` in where the
+    the project header(s) were included. Some headers came
+    before, others came after. It seems that doesn't work:
+    any header should preceded the `import` statements or
+    the `module` name declaration.
+
+- Especially in the tests I hadn't always included all headers
+    for standard library components which may be potentially
+    used. However, these are necessary, even if the standard
+    library component isn't even named and just used. For
+    example:
+
+    ```c++
+    #include <tuple>
+    import beman.execution;
+    namespace ex = beman::execution;
+
+    int main() {
+        auto[rc] = *ex::sync_wait(ex::just(0));
+        return rc;
+    }
+    ```
+
+    Removing `#include <tuple>` causes a compilation failure:
+    `sync_wait` return an `std::optional<std::tuple<T...>>` and the
+    structured binding needs to know about the `std::tuple`. Oddly,
+    the `std::optional` can be deferenced.
+
+- My biggest blocker was the definition of `join_env`: the original
+    definition used a `requires` clause which checked whether at
+    least one of two expressions were values. Implementation used
+    an `if constexpr` to decide whether the first of the two
+    expression is value and used that and otherwise the other
+    expression would be used. That is, something like this:
+
+    ```c++
+    template <typename E1, typename E2>
+    struct join_env {
+        E1 e1;
+        E2 e2;
+        template <typename Q>
+            requires(
+                requires(Q q, const E1& e){ q(e); } ||
+                requires(Q q, const E2& e){ q(e); }
+            )
+        auto query(Q q) const noexcept {
+            if constexpr (requires(Q q, const E1& e){ q(e); })
+                return q(this->e1);
+            else
+                return q(this->e2);
+        }
+    };
+    ```
+
+    However, the compiler insisted in the definition of the function
+    that neither of the two expressions from the `requires` clause
+    was valid. Eventually I just turned the `query` into two
+    overloads, the first requring that `q(e1)` is valid and the
+    second requiring that `q(e1)` is not valid but `q(e2)` is valid.
+    I think it was only one compiler causing this issue.
+
+## Scanning and Building
+
+One of the things which seems odd is that each time `beman.execution`
+is built, the files are scanned for dependencies. That scanning
+often takes longer than the actual build of the respective object
+file.  Also, since the `module` gets rebuild, all the tests `import`ing
+the `module` get built again. When developing with including headers
+only the tests which included modified headers (possibly indirectly)
+needed to be rebuilt. Since the components and tests were created
+in dependency order, that normally meant that only one test needed
+to be rebuilt. Only if an already tested component needed to be
+changed multiple tests needed to be built.
+
+The promise of `module`s was that builds get faster. I don't have
+objective measurements but it seems the development actually got
+slower. While concentrating on fixing a particular componenent I
+often removed all other tests and the examples from the build.
 
 ## Modules vs. Testing
 
+Testing the `module` components is, yet, another issue! There are
+a few issues and I haven't worked out all of them, yet:
+
+1. There are quite a few classes and functions which are implementation
+    details. I like to test these. In fact, I normally don't use `private`
+    member functions because I can't test them. Instead, this functionality
+    would become `public` members of an implementation class which then
+    becomes a `private` member of the actual component. The implementation
+    class can be tested separately. However, anything which isn't `export`ed
+    isn't accessible from outside the `module`.
+
+    I still want to test that the `module` works, including all the
+    implementation details. Currently, the implementation details
+    are tested by just using the headers to get the declarations.
+    That doesn't seem quite right, though. Maybe the way to is to
+    have a second `module` for the implementation details, say,
+    `beman.execution.detail`, and use that to test the implementation
+    details.
+
+2. Some tests would benefit from common tools. For example, there could be
+    a `test::scheduler` which is used to verify that the various scheduling
+    operations do the right thing. A `test::scheduler` would be defined in
+    a header and included into each test. Of course, the `test::scheduler`
+    would need the declarations of some `module` components, e.g., of
+    `set_value_t` and, thus, use `import beman.execution`.
+
+    That didn't quite occur to me but it _seems_ that may actually work!
+    An initial test seems to show that the compilers do not get upset about
+    multiple `import beman.execution` statements.
+
+## Conclusion
+
+So far it isn't clear to me whether `module`s do provide a benefit. The
+main sticking points are:
+
+1. I don't known, yet, how to test implementation details without `export`ing
+    them.
+2. The "scan deps" step seems to take quite long.
+3. So far I haven't managed to avoid `export`ing some of the implementation
+    details. However, that _may_ be due to some uses actually requiring them.
+4. There is different behavior between different compilers.
+
+Some of the issues I encountered are likely due to ignorance: probably
+all issues can be resolved with a bit of adjusted practices.
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index c68e6e17..cb15a9cd 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -35,7 +35,7 @@ set(EXAMPLES
 )
 
 if(BEMAN_USE_MODULES)
-    list(APPEND EXAMPLES modules) # modules.cpp
+    list(APPEND EXAMPLES modules modules-and-header)
 endif()
 
 foreach(EXAMPLE ${EXAMPLES})
diff --git a/examples/modules-and-header.cpp b/examples/modules-and-header.cpp
new file mode 100644
index 00000000..b531140c
--- /dev/null
+++ b/examples/modules-and-header.cpp
@@ -0,0 +1,11 @@
+// examples/modules-and-header.cpp                                    -*-C++-*-
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <tuple>
+import beman.execution;
+namespace ex = beman::execution;
+
+int main() {
+    auto [rc] = *ex::sync_wait(ex::just(0));
+    return rc;
+}
diff --git a/include/beman/execution/detail/affine_on.hpp b/include/beman/execution/detail/affine_on.hpp
index 44078900..d86d0164 100644
--- a/include/beman/execution/detail/affine_on.hpp
+++ b/include/beman/execution/detail/affine_on.hpp
@@ -134,8 +134,8 @@ namespace beman::execution {
  * @brief affine_on is a CPO, used to adapt a sender to complete on the scheduler
  *      it got started on which is derived from get_scheduler on the receiver's environment.
  */
-BEMAN_EXECUTION_EXPORT using affine_on_t = beman::execution::detail::affine_on_t;
-BEMAN_EXECUTION_EXPORT inline constexpr affine_on_t affine_on{};
+using affine_on_t = beman::execution::detail::affine_on_t;
+inline constexpr affine_on_t affine_on{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/apply_sender.hpp b/include/beman/execution/detail/apply_sender.hpp
index 2cc63a66..2c079a5e 100644
--- a/include/beman/execution/detail/apply_sender.hpp
+++ b/include/beman/execution/detail/apply_sender.hpp
@@ -16,7 +16,7 @@ namespace beman::execution {
  * \brief Function used to transform a sender and its arguments for a domain.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
+template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
     requires requires(Domain domain, Tag tag, Sender&& sender, Args&&... args) {
         domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
     }
@@ -29,7 +29,7 @@ constexpr auto apply_sender(Domain domain, Tag, Sender&& sender, Args&&... args)
  * \brief Default function used to transform a second and its arguments.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
+template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
     requires(not requires(Domain domain, Tag tag, Sender&& sender, Args&&... args) {
                 domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
             }) && requires(Tag tag, Sender&& sender, Args&&... args) {
diff --git a/include/beman/execution/detail/as_awaitable.hpp b/include/beman/execution/detail/as_awaitable.hpp
index c299be5b..68fa058a 100644
--- a/include/beman/execution/detail/as_awaitable.hpp
+++ b/include/beman/execution/detail/as_awaitable.hpp
@@ -21,7 +21,7 @@ namespace beman::execution {
  * \brief Turn an entity, e.g., a sender, into an awaitable.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT struct as_awaitable_t {
+struct as_awaitable_t {
     template <typename Expr, typename Promise>
     auto operator()(Expr&& expr, Promise& promise) const {
         if constexpr (requires { ::std::forward<Expr>(expr).as_awaitable(promise); }) {
@@ -39,7 +39,7 @@ BEMAN_EXECUTION_EXPORT struct as_awaitable_t {
         }
     }
 };
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::as_awaitable_t as_awaitable{};
+inline constexpr ::beman::execution::as_awaitable_t as_awaitable{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/associate.hpp b/include/beman/execution/detail/associate.hpp
index 85001d2f..a9adf72d 100644
--- a/include/beman/execution/detail/associate.hpp
+++ b/include/beman/execution/detail/associate.hpp
@@ -21,8 +21,8 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution::detail {
-BEMAN_EXECUTION_EXPORT template <::beman::execution::scope_token Token,
-                                 ::beman::execution::sender      Sender> //-dk:TODO detail export
+template <::beman::execution::scope_token Token,
+          ::beman::execution::sender      Sender> //-dk:TODO detail export
 struct associate_data {
     using wrap_sender = ::std::remove_cvref_t<decltype(::std::declval<Token&>().wrap(::std::declval<Sender>()))>;
 
@@ -65,7 +65,7 @@ struct associate_data {
     Token                        token;
     ::std::optional<wrap_sender> sender;
 };
-BEMAN_EXECUTION_EXPORT template <::beman::execution::scope_token Token, ::beman::execution::sender Sender>
+template <::beman::execution::scope_token Token, ::beman::execution::sender Sender>
 associate_data(Token, Sender&&) -> associate_data<Token, Sender>;
 
 struct associate_t {
@@ -162,8 +162,8 @@ struct completion_signatures_for_impl<
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using associate_t = ::beman::execution::detail::associate_t;
-BEMAN_EXECUTION_EXPORT inline constexpr associate_t associate{};
+using associate_t = ::beman::execution::detail::associate_t;
+inline constexpr associate_t associate{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/await_result_type.hpp b/include/beman/execution/detail/await_result_type.hpp
index 6de785d1..c5d959c3 100644
--- a/include/beman/execution/detail/await_result_type.hpp
+++ b/include/beman/execution/detail/await_result_type.hpp
@@ -16,7 +16,7 @@ namespace beman::execution::detail {
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  * \internal
  */
-BEMAN_EXECUTION_EXPORT template <typename T, typename Promise> //-dk:TODO detail export
+template <typename T, typename Promise> //-dk:TODO detail export
 using await_result_type =
     decltype(::beman::execution::detail::get_awaiter(::std::declval<T>(), ::std::declval<Promise&>()).await_resume());
 } // namespace beman::execution::detail
diff --git a/include/beman/execution/detail/basic_operation.hpp b/include/beman/execution/detail/basic_operation.hpp
index fd6f8d1a..8ba4fdb1 100644
--- a/include/beman/execution/detail/basic_operation.hpp
+++ b/include/beman/execution/detail/basic_operation.hpp
@@ -26,7 +26,7 @@ namespace beman::execution::detail {
  * \internal
  */
 //-dk:TODO the export below shouldn't be needed, but MSVC++ seems to require it (2026-02-01)
-BEMAN_EXECUTION_EXPORT template <typename Sender, typename Receiver> //-dk:TODO detail export
+template <typename Sender, typename Receiver> //-dk:TODO detail export
     requires ::beman::execution::detail::
         //-dk:TODO why is the remove_cvref_t needed...?
     valid_specialization<::beman::execution::detail::state_type, std::remove_cvref_t<Sender>, Receiver>
diff --git a/include/beman/execution/detail/basic_state.hpp b/include/beman/execution/detail/basic_state.hpp
index 5542371b..128fb7a6 100644
--- a/include/beman/execution/detail/basic_state.hpp
+++ b/include/beman/execution/detail/basic_state.hpp
@@ -21,7 +21,7 @@ namespace beman::execution::detail {
  * \internal
  */
 //-dk:TODO the export below shouldn't be needed, but MSVC++ seems to require it (2026-02-01)
-BEMAN_EXECUTION_EXPORT template <typename Sender, typename Receiver> //-dk:TODO detail export
+template <typename Sender, typename Receiver> //-dk:TODO detail export
 struct basic_state {
     basic_state(Sender&& sender, Receiver&& rcvr) noexcept(true)
         : receiver(::std::move(rcvr)),
diff --git a/include/beman/execution/detail/bulk.hpp b/include/beman/execution/detail/bulk.hpp
index b2ace14a..cdcc896d 100644
--- a/include/beman/execution/detail/bulk.hpp
+++ b/include/beman/execution/detail/bulk.hpp
@@ -136,8 +136,8 @@ struct completion_signatures_for_impl<
 
 namespace beman::execution {
 
-BEMAN_EXECUTION_EXPORT using bulk_t = ::beman::execution::detail::bulk_t;
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::bulk_t bulk{};
+using bulk_t = ::beman::execution::detail::bulk_t;
+inline constexpr ::beman::execution::bulk_t bulk{};
 
 } // namespace beman::execution
 
diff --git a/include/beman/execution/detail/common.hpp b/include/beman/execution/detail/common.hpp
index 975537a8..055ba2b9 100644
--- a/include/beman/execution/detail/common.hpp
+++ b/include/beman/execution/detail/common.hpp
@@ -6,10 +6,6 @@
 
 // ----------------------------------------------------------------------------
 
-#ifndef BEMAN_EXECUTION_EXPORT
-#define BEMAN_EXECUTION_EXPORT
-#endif
-
 #if defined(disabled__cpp_deleted_function)
 #define BEMAN_EXECUTION_DELETE(msg) delete (msg)
 #else
diff --git a/include/beman/execution/detail/completion_signatures.hpp b/include/beman/execution/detail/completion_signatures.hpp
index a7a8d449..0da03b1d 100644
--- a/include/beman/execution/detail/completion_signatures.hpp
+++ b/include/beman/execution/detail/completion_signatures.hpp
@@ -21,7 +21,7 @@ namespace beman::execution {
  * any specializaion are empty. Objects may be created to return them from
  * functions used for type computations like get_completion_signatures(sender, env).
  */
-BEMAN_EXECUTION_EXPORT template <::beman::execution::detail::completion_signature...>
+template <::beman::execution::detail::completion_signature...>
 struct completion_signatures {};
 } // namespace beman::execution
 
diff --git a/include/beman/execution/detail/completion_signatures_of_t.hpp b/include/beman/execution/detail/completion_signatures_of_t.hpp
index 3b6d6748..2336713c 100644
--- a/include/beman/execution/detail/completion_signatures_of_t.hpp
+++ b/include/beman/execution/detail/completion_signatures_of_t.hpp
@@ -17,7 +17,7 @@ namespace beman::execution {
  * \brief Alias to access the completion signatures of a sender
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT template <typename Sender, typename Env = ::beman::execution::env<>>
+template <typename Sender, typename Env = ::beman::execution::env<>>
     requires ::beman::execution::sender_in<Sender, Env>
 using completion_signatures_of_t =
     ::beman::execution::detail::call_result_t<::beman::execution::get_completion_signatures_t, Sender, Env>;
diff --git a/include/beman/execution/detail/connect.hpp b/include/beman/execution/detail/connect.hpp
index f4e30b07..d7584bd3 100644
--- a/include/beman/execution/detail/connect.hpp
+++ b/include/beman/execution/detail/connect.hpp
@@ -22,7 +22,7 @@ namespace beman::execution::detail {
  * \internal
  */
 //-dk:TODO this seems to needed for MSVC++ (2026-01-30)
-BEMAN_EXECUTION_EXPORT struct connect_t {
+struct connect_t {
   private:
     template <typename Sender, typename Receiver>
     static auto make_new_sender(Sender&& sender, Receiver&& receiver)
@@ -83,7 +83,7 @@ namespace beman::execution {
  * \brief Type of the connect customization point object.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT using connect_t = beman::execution::detail::connect_t;
+using connect_t = beman::execution::detail::connect_t;
 /*!
  * \brief Customization point object used to connect a sender and a receiver.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
@@ -92,7 +92,7 @@ BEMAN_EXECUTION_EXPORT using connect_t = beman::execution::detail::connect_t;
  * `connect(sender, receiver)` returns the result of calling `sender.connect(receiver)`.
  * The returned object `state` is an `operation_state` object.
  */
-BEMAN_EXECUTION_EXPORT inline constexpr connect_t connect{};
+inline constexpr connect_t connect{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/connect_all.hpp b/include/beman/execution/detail/connect_all.hpp
index cbba0645..ec2d3c6e 100644
--- a/include/beman/execution/detail/connect_all.hpp
+++ b/include/beman/execution/detail/connect_all.hpp
@@ -123,7 +123,7 @@ struct connect_all_t {
  * \internal
  */
 //-dk:TODO the export below shouldn't be needed, but MSVC++ seems to require it (2026-02-01)
-BEMAN_EXECUTION_EXPORT inline constexpr connect_all_t connect_all{}; //-dk:TODO detail export
+inline constexpr connect_all_t connect_all{}; //-dk:TODO detail export
 } // namespace beman::execution::detail
 
 #include <beman/execution/detail/suppress_pop.hpp>
diff --git a/include/beman/execution/detail/connect_result_t.hpp b/include/beman/execution/detail/connect_result_t.hpp
index 0d821b68..f41e9f19 100644
--- a/include/beman/execution/detail/connect_result_t.hpp
+++ b/include/beman/execution/detail/connect_result_t.hpp
@@ -15,7 +15,7 @@ namespace beman::execution {
  * \brief Type alias to determine the operation state type returned from `connect()`.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT template <typename Sender, typename Receiver>
+template <typename Sender, typename Receiver>
 using connect_result_t = decltype(::beman::execution::connect(::std::declval<Sender>(), ::std::declval<Receiver>()));
 } // namespace beman::execution
 
diff --git a/include/beman/execution/detail/continues_on.hpp b/include/beman/execution/detail/continues_on.hpp
index 02a5f52d..bbeba96b 100644
--- a/include/beman/execution/detail/continues_on.hpp
+++ b/include/beman/execution/detail/continues_on.hpp
@@ -90,12 +90,12 @@ auto get_domain_late(Sender&& sender, Env&&) {
 #include <beman/execution/detail/suppress_pop.hpp>
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using continues_on_t = ::beman::execution::detail::continues_on_t;
+using continues_on_t = ::beman::execution::detail::continues_on_t;
 /*!
  * \brief Customization point object to create a `continues_on` sender.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr continues_on_t continues_on{};
+inline constexpr continues_on_t continues_on{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/counting_scope.hpp b/include/beman/execution/detail/counting_scope.hpp
index fb1c51d5..413aab92 100644
--- a/include/beman/execution/detail/counting_scope.hpp
+++ b/include/beman/execution/detail/counting_scope.hpp
@@ -17,7 +17,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT class counting_scope;
+class counting_scope;
 }
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/default_domain.hpp b/include/beman/execution/detail/default_domain.hpp
index bb29e791..bb9c91fc 100644
--- a/include/beman/execution/detail/default_domain.hpp
+++ b/include/beman/execution/detail/default_domain.hpp
@@ -25,7 +25,7 @@ namespace beman::execution {
  * tag type of the passed sender. If there is no corresponding member function
  * no transformation is applied.
  */
-BEMAN_EXECUTION_EXPORT struct default_domain {
+struct default_domain {
     template <::beman::execution::sender Sender, ::beman::execution::detail::queryable... Env>
         requires(sizeof...(Env) <= 1) && requires(Sender&& sender, Env&&... env) {
             ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
diff --git a/include/beman/execution/detail/env.hpp b/include/beman/execution/detail/env.hpp
index 9b87229b..383f00b1 100644
--- a/include/beman/execution/detail/env.hpp
+++ b/include/beman/execution/detail/env.hpp
@@ -37,7 +37,7 @@ struct find_env<Q, E0, E...> {
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <::beman::execution::detail::queryable... Envs>
+template <::beman::execution::detail::queryable... Envs>
 struct env : ::beman::execution::detail::env_base<Envs>... {
     [[no_unique_address]] ::beman::execution::detail::non_assignable na_{};
 
diff --git a/include/beman/execution/detail/env_of_t.hpp b/include/beman/execution/detail/env_of_t.hpp
index 0983b67d..0f3e0f8e 100644
--- a/include/beman/execution/detail/env_of_t.hpp
+++ b/include/beman/execution/detail/env_of_t.hpp
@@ -15,7 +15,7 @@ namespace beman::execution {
  * \brief Determine the type of the environment associated with a type
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT template <typename T>
+template <typename T>
 using env_of_t = decltype(::beman::execution::get_env(::std::declval<T>()));
 } // namespace beman::execution
 
diff --git a/include/beman/execution/detail/env_promise.hpp b/include/beman/execution/detail/env_promise.hpp
index b8594dad..d12b23ea 100644
--- a/include/beman/execution/detail/env_promise.hpp
+++ b/include/beman/execution/detail/env_promise.hpp
@@ -16,7 +16,7 @@ namespace beman::execution::detail {
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  * \internal
  */
-BEMAN_EXECUTION_EXPORT template <typename Env> //-dk:TODO detail export
+template <typename Env> //-dk:TODO detail export
 struct env_promise : ::beman::execution::detail::with_await_transform<Env> {
     auto get_return_object() noexcept -> void;
     auto initial_suspend() noexcept -> ::std::suspend_always;
diff --git a/include/beman/execution/detail/error_types_of_t.hpp b/include/beman/execution/detail/error_types_of_t.hpp
index 4464805d..aea141b9 100644
--- a/include/beman/execution/detail/error_types_of_t.hpp
+++ b/include/beman/execution/detail/error_types_of_t.hpp
@@ -20,9 +20,9 @@ namespace beman::execution {
  * \brief Type alias to get error types for a sender
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT template <typename Sender,
-                                 typename Env                         = ::beman::execution::env<>,
-                                 template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
+template <typename Sender,
+          typename Env                         = ::beman::execution::env<>,
+          template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
     requires ::beman::execution::sender_in<Sender, Env>
 using error_types_of_t =
     ::beman::execution::detail::gather_signatures<::beman::execution::set_error_t,
diff --git a/include/beman/execution/detail/forwarding_query.hpp b/include/beman/execution/detail/forwarding_query.hpp
index bad9d974..c71535b9 100644
--- a/include/beman/execution/detail/forwarding_query.hpp
+++ b/include/beman/execution/detail/forwarding_query.hpp
@@ -37,7 +37,7 @@ namespace beman::execution {
  * \brief Type of the forwarding_query customization point object
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT using forwarding_query_t = beman::execution::detail::forwarding_query_t;
+using forwarding_query_t = beman::execution::detail::forwarding_query_t;
 /*!
  * \brief The customization point object to determine whether queries should be forwarded
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
@@ -50,7 +50,7 @@ BEMAN_EXECUTION_EXPORT using forwarding_query_t = beman::execution::detail::forw
  * * If the type of `q` is derived from `forwarding_query_t`.
  * * `false` otherwise.
  */
-BEMAN_EXECUTION_EXPORT inline constexpr forwarding_query_t forwarding_query{};
+inline constexpr forwarding_query_t forwarding_query{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/fwd_env.hpp b/include/beman/execution/detail/fwd_env.hpp
index e85eaee4..b71d11ea 100644
--- a/include/beman/execution/detail/fwd_env.hpp
+++ b/include/beman/execution/detail/fwd_env.hpp
@@ -19,7 +19,7 @@ namespace beman::execution::detail {
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  * \internal
  */
-BEMAN_EXECUTION_EXPORT template <typename Env> //-dk:TODO detail export
+template <typename Env> //-dk:TODO detail export
 class fwd_env {
   private:
     Env env;
diff --git a/include/beman/execution/detail/get_allocator.hpp b/include/beman/execution/detail/get_allocator.hpp
index dc54c3ac..0ae11ecf 100644
--- a/include/beman/execution/detail/get_allocator.hpp
+++ b/include/beman/execution/detail/get_allocator.hpp
@@ -15,7 +15,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct get_allocator_t {
+struct get_allocator_t {
     template <typename Object>
         requires(not requires(Object&& object, const get_allocator_t& tag) { ::std::as_const(object).query(tag); })
     auto
@@ -50,7 +50,7 @@ BEMAN_EXECUTION_EXPORT struct get_allocator_t {
     constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr get_allocator_t get_allocator{};
+inline constexpr get_allocator_t get_allocator{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/get_completion_scheduler.hpp b/include/beman/execution/detail/get_completion_scheduler.hpp
index 517169dc..725e474f 100644
--- a/include/beman/execution/detail/get_completion_scheduler.hpp
+++ b/include/beman/execution/detail/get_completion_scheduler.hpp
@@ -23,7 +23,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Tag>
+template <typename Tag>
 struct get_completion_scheduler_t;
 
 template <typename Tag>
@@ -78,7 +78,7 @@ struct get_completion_scheduler_t : ::beman::execution::forwarding_query_t {
     }
 };
 
-BEMAN_EXECUTION_EXPORT template <::beman::execution::detail::completion_tag Tag>
+template <::beman::execution::detail::completion_tag Tag>
 inline constexpr get_completion_scheduler_t<Tag> get_completion_scheduler{};
 } // namespace beman::execution
 
diff --git a/include/beman/execution/detail/get_completion_signatures.hpp b/include/beman/execution/detail/get_completion_signatures.hpp
index 330591f8..a172ec6e 100644
--- a/include/beman/execution/detail/get_completion_signatures.hpp
+++ b/include/beman/execution/detail/get_completion_signatures.hpp
@@ -20,7 +20,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct get_completion_signatures_t {
+struct get_completion_signatures_t {
   private:
     template <typename Sender, typename Env>
     static auto get(Sender&& sender, Env&& env) noexcept {
@@ -61,7 +61,7 @@ BEMAN_EXECUTION_EXPORT struct get_completion_signatures_t {
         return this->get(::std::forward<Sender>(sender), ::std::forward<Env>(env));
     }
 };
-BEMAN_EXECUTION_EXPORT inline constexpr get_completion_signatures_t get_completion_signatures{};
+inline constexpr get_completion_signatures_t get_completion_signatures{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/get_delegation_scheduler.hpp b/include/beman/execution/detail/get_delegation_scheduler.hpp
index 427d6086..61c21874 100644
--- a/include/beman/execution/detail/get_delegation_scheduler.hpp
+++ b/include/beman/execution/detail/get_delegation_scheduler.hpp
@@ -12,7 +12,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct get_delegation_scheduler_t {
+struct get_delegation_scheduler_t {
     template <typename Env>
         requires requires(Env&& env, const get_delegation_scheduler_t& g) {
             { ::std::as_const(env).query(g) } noexcept -> ::beman::execution::scheduler;
@@ -23,7 +23,7 @@ BEMAN_EXECUTION_EXPORT struct get_delegation_scheduler_t {
     constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr get_delegation_scheduler_t get_delegation_scheduler{};
+inline constexpr get_delegation_scheduler_t get_delegation_scheduler{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/get_domain.hpp b/include/beman/execution/detail/get_domain.hpp
index 58daf7e3..932e1147 100644
--- a/include/beman/execution/detail/get_domain.hpp
+++ b/include/beman/execution/detail/get_domain.hpp
@@ -13,7 +13,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct get_domain_t {
+struct get_domain_t {
     template <typename Object>
         requires(not requires(Object&& object, const get_domain_t& tag) {
                     ::std::forward<Object>(object).query(tag);
@@ -37,7 +37,7 @@ BEMAN_EXECUTION_EXPORT struct get_domain_t {
     constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr get_domain_t get_domain{};
+inline constexpr get_domain_t get_domain{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/get_env.hpp b/include/beman/execution/detail/get_env.hpp
index 718163df..ab030f53 100644
--- a/include/beman/execution/detail/get_env.hpp
+++ b/include/beman/execution/detail/get_env.hpp
@@ -13,7 +13,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct get_env_t {
+struct get_env_t {
     template <typename Object>
         requires(not requires(::std::add_const_t<::std::remove_cvref_t<Object>>& object) { object.get_env(); } ||
                  ::beman::execution::detail::queryable<
@@ -31,7 +31,7 @@ BEMAN_EXECUTION_EXPORT struct get_env_t {
     }
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr get_env_t get_env{};
+inline constexpr get_env_t get_env{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/get_scheduler.hpp b/include/beman/execution/detail/get_scheduler.hpp
index 9daac011..3ab03070 100644
--- a/include/beman/execution/detail/get_scheduler.hpp
+++ b/include/beman/execution/detail/get_scheduler.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct get_scheduler_t : ::beman::execution::forwarding_query_t {
+struct get_scheduler_t : ::beman::execution::forwarding_query_t {
     template <typename Env>
         requires requires(const get_scheduler_t& self, Env&& env) { ::std::as_const(env).query(self); }
     auto operator()(Env&& env) const noexcept {
@@ -24,7 +24,7 @@ BEMAN_EXECUTION_EXPORT struct get_scheduler_t : ::beman::execution::forwarding_q
     }
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr get_scheduler_t get_scheduler{};
+inline constexpr get_scheduler_t get_scheduler{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/get_stop_token.hpp b/include/beman/execution/detail/get_stop_token.hpp
index 45d0278b..b81bc5ea 100644
--- a/include/beman/execution/detail/get_stop_token.hpp
+++ b/include/beman/execution/detail/get_stop_token.hpp
@@ -18,7 +18,7 @@ template <typename Token>
 concept decayed_stoppable_token = ::beman::execution::stoppable_token<::std::decay_t<Token>>;
 }
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct get_stop_token_t {
+struct get_stop_token_t {
     template <typename Object>
         requires requires(Object&& object, const get_stop_token_t& tag) {
             { ::std::as_const(object).query(tag) } noexcept -> ::beman::execution::detail::decayed_stoppable_token;
@@ -35,7 +35,7 @@ BEMAN_EXECUTION_EXPORT struct get_stop_token_t {
     constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr get_stop_token_t get_stop_token{};
+inline constexpr get_stop_token_t get_stop_token{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/indices_for.hpp b/include/beman/execution/detail/indices_for.hpp
index 75358276..8c1a12b6 100644
--- a/include/beman/execution/detail/indices_for.hpp
+++ b/include/beman/execution/detail/indices_for.hpp
@@ -11,7 +11,7 @@
 
 namespace beman::execution::detail {
 //-dk:TODO the export below shouldn't be needed, but MSVC++ seems to require it (2026-02-01)
-BEMAN_EXECUTION_EXPORT template <typename Sender> //-dk:TODO detail export
+template <typename Sender> //-dk:TODO detail export
 using indices_for = typename ::std::remove_reference_t<Sender>::indices_for;
 } // namespace beman::execution::detail
 
diff --git a/include/beman/execution/detail/inplace_stop_source.hpp b/include/beman/execution/detail/inplace_stop_source.hpp
index 214f409f..f010dd53 100644
--- a/include/beman/execution/detail/inplace_stop_source.hpp
+++ b/include/beman/execution/detail/inplace_stop_source.hpp
@@ -15,11 +15,11 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT class inplace_stop_token;
-BEMAN_EXECUTION_EXPORT class inplace_stop_source;
-BEMAN_EXECUTION_EXPORT template <typename CallbackFun>
+class inplace_stop_token;
+class inplace_stop_source;
+template <typename CallbackFun>
 class inplace_stop_callback;
-BEMAN_EXECUTION_EXPORT template <typename CallbackFun>
+template <typename CallbackFun>
 inplace_stop_callback(::beman::execution::inplace_stop_token, CallbackFun) -> inplace_stop_callback<CallbackFun>;
 } // namespace beman::execution
 
diff --git a/include/beman/execution/detail/into_variant.hpp b/include/beman/execution/detail/into_variant.hpp
index b4ff8169..b494a9cb 100644
--- a/include/beman/execution/detail/into_variant.hpp
+++ b/include/beman/execution/detail/into_variant.hpp
@@ -30,7 +30,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution::detail {
-BEMAN_EXECUTION_EXPORT struct into_variant_t {
+struct into_variant_t {
     template <::beman::execution::sender Sender>
     auto operator()(Sender&& sender) const {
         auto domain{::beman::execution::detail::get_domain_early(sender)};
@@ -101,8 +101,8 @@ struct completion_signatures_for_impl<
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using into_variant_t = ::beman::execution::detail::into_variant_t;
-BEMAN_EXECUTION_EXPORT inline constexpr into_variant_t into_variant{};
+using into_variant_t = ::beman::execution::detail::into_variant_t;
+inline constexpr into_variant_t into_variant{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/just.hpp b/include/beman/execution/detail/just.hpp
index 1d858cb8..9de59bb5 100644
--- a/include/beman/execution/detail/just.hpp
+++ b/include/beman/execution/detail/just.hpp
@@ -65,9 +65,9 @@ struct impls_for<just_t<Completion>> : ::beman::execution::detail::default_impls
 #include <beman/execution/detail/suppress_pop.hpp>
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using just_t         = ::beman::execution::detail::just_t<::beman::execution::set_value_t>;
-BEMAN_EXECUTION_EXPORT using just_error_t   = ::beman::execution::detail::just_t<::beman::execution::set_error_t>;
-BEMAN_EXECUTION_EXPORT using just_stopped_t = ::beman::execution::detail::just_t<::beman::execution::set_stopped_t>;
+using just_t         = ::beman::execution::detail::just_t<::beman::execution::set_value_t>;
+using just_error_t   = ::beman::execution::detail::just_t<::beman::execution::set_error_t>;
+using just_stopped_t = ::beman::execution::detail::just_t<::beman::execution::set_stopped_t>;
 
 /*!
  * \brief <code>just(_arg_...)</code> yields a sender completing with <code>set_value_t(_Arg_...)</code>
@@ -118,7 +118,7 @@ BEMAN_EXECUTION_EXPORT using just_stopped_t = ::beman::execution::detail::just_t
  * }
  * </pre>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::just_t just{};
+inline constexpr ::beman::execution::just_t just{};
 
 /*!
  * \brief <code>just_error(_error_)</code> yields a sender completing with <code>set_error_t(_Error_)</code>
@@ -176,7 +176,7 @@ BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::just_t just{};
  * }
  * </pre>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::just_error_t just_error{};
+inline constexpr ::beman::execution::just_error_t just_error{};
 
 /*!
  * \brief <code>just_stopped()</code> yields a sender completing with <code>set_stopped_t()</code>
@@ -230,7 +230,7 @@ BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::just_error_t just_er
  * }
  * </pre>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::just_stopped_t just_stopped{};
+inline constexpr ::beman::execution::just_stopped_t just_stopped{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/let.hpp b/include/beman/execution/detail/let.hpp
index ace849b1..5d54d54c 100644
--- a/include/beman/execution/detail/let.hpp
+++ b/include/beman/execution/detail/let.hpp
@@ -239,13 +239,13 @@ struct completion_signatures_for_impl<
 #include <beman/execution/detail/suppress_pop.hpp>
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using let_error_t   = ::beman::execution::detail::let_t<::beman::execution::set_error_t>;
-BEMAN_EXECUTION_EXPORT using let_stopped_t = ::beman::execution::detail::let_t<::beman::execution::set_stopped_t>;
-BEMAN_EXECUTION_EXPORT using let_value_t   = ::beman::execution::detail::let_t<::beman::execution::set_value_t>;
+using let_error_t   = ::beman::execution::detail::let_t<::beman::execution::set_error_t>;
+using let_stopped_t = ::beman::execution::detail::let_t<::beman::execution::set_stopped_t>;
+using let_value_t   = ::beman::execution::detail::let_t<::beman::execution::set_value_t>;
 
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::let_error_t   let_error{};
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::let_stopped_t let_stopped{};
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::let_value_t   let_value{};
+inline constexpr ::beman::execution::let_error_t   let_error{};
+inline constexpr ::beman::execution::let_stopped_t let_stopped{};
+inline constexpr ::beman::execution::let_value_t   let_value{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/make_env.hpp b/include/beman/execution/detail/make_env.hpp
index 535e84cc..b93fdd3c 100644
--- a/include/beman/execution/detail/make_env.hpp
+++ b/include/beman/execution/detail/make_env.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution::detail {
-BEMAN_EXECUTION_EXPORT template <typename Query, typename Value> //-dk:TODO detail export
+template <typename Query, typename Value> //-dk:TODO detail export
 class make_env {
   private:
     Value value;
diff --git a/include/beman/execution/detail/never_stop_token.hpp b/include/beman/execution/detail/never_stop_token.hpp
index 003f2b17..7329e439 100644
--- a/include/beman/execution/detail/never_stop_token.hpp
+++ b/include/beman/execution/detail/never_stop_token.hpp
@@ -9,7 +9,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT class never_stop_token;
+class never_stop_token;
 }
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/nostopstate.hpp b/include/beman/execution/detail/nostopstate.hpp
index b4763343..aeb5aa0b 100644
--- a/include/beman/execution/detail/nostopstate.hpp
+++ b/include/beman/execution/detail/nostopstate.hpp
@@ -9,11 +9,11 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct nostopstate_t {
+struct nostopstate_t {
     explicit nostopstate_t() = default;
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr nostopstate_t nostopstate{};
+inline constexpr nostopstate_t nostopstate{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/on.hpp b/include/beman/execution/detail/on.hpp
index 6038e756..93ed4806 100644
--- a/include/beman/execution/detail/on.hpp
+++ b/include/beman/execution/detail/on.hpp
@@ -136,8 +136,8 @@ struct on_t : ::beman::execution::sender_adaptor_closure<on_t> {
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using on_t = ::beman::execution::detail::on_t;
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::on_t on{};
+using on_t = ::beman::execution::detail::on_t;
+inline constexpr ::beman::execution::on_t on{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/operation_state.hpp b/include/beman/execution/detail/operation_state.hpp
index d1a9a2a8..20d295e8 100644
--- a/include/beman/execution/detail/operation_state.hpp
+++ b/include/beman/execution/detail/operation_state.hpp
@@ -12,9 +12,9 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct operation_state_t {};
+struct operation_state_t {};
 
-BEMAN_EXECUTION_EXPORT template <typename State>
+template <typename State>
 concept operation_state =
     ::std::derived_from<typename State::operation_state_concept, ::beman::execution::operation_state_t> &&
     ::std::is_object_v<State> && requires(State& state) {
diff --git a/include/beman/execution/detail/product_type.hpp b/include/beman/execution/detail/product_type.hpp
index b3951e61..490dd365 100644
--- a/include/beman/execution/detail/product_type.hpp
+++ b/include/beman/execution/detail/product_type.hpp
@@ -6,6 +6,7 @@
 
 #include <beman/execution/detail/common.hpp>
 #include <memory>
+#include <tuple>
 #include <cstddef>
 
 #include <beman/execution/detail/suppress_push.hpp>
diff --git a/include/beman/execution/detail/prop.hpp b/include/beman/execution/detail/prop.hpp
index c5086bec..5fe43e29 100644
--- a/include/beman/execution/detail/prop.hpp
+++ b/include/beman/execution/detail/prop.hpp
@@ -17,7 +17,7 @@ struct prop_like;
 }
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Query, typename Value>
+template <typename Query, typename Value>
 struct prop;
 
 template <typename Query, typename Value>
diff --git a/include/beman/execution/detail/read_env.hpp b/include/beman/execution/detail/read_env.hpp
index aec3b0df..fceab7c5 100644
--- a/include/beman/execution/detail/read_env.hpp
+++ b/include/beman/execution/detail/read_env.hpp
@@ -57,8 +57,8 @@ struct completion_signatures_for_impl<
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using read_env_t = beman::execution::detail::read_env_t;
-BEMAN_EXECUTION_EXPORT inline constexpr read_env_t read_env{};
+using read_env_t = beman::execution::detail::read_env_t;
+inline constexpr read_env_t read_env{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/receiver.hpp b/include/beman/execution/detail/receiver.hpp
index a05ed1ee..ce4a84c9 100644
--- a/include/beman/execution/detail/receiver.hpp
+++ b/include/beman/execution/detail/receiver.hpp
@@ -13,9 +13,9 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct receiver_t {};
+struct receiver_t {};
 
-BEMAN_EXECUTION_EXPORT template <typename Rcvr>
+template <typename Rcvr>
 concept receiver =
     ::std::derived_from<typename ::std::remove_cvref_t<Rcvr>::receiver_concept, ::beman::execution::receiver_t> &&
     requires(const ::std::remove_cvref_t<Rcvr>& rcvr) {
diff --git a/include/beman/execution/detail/receiver_of.hpp b/include/beman/execution/detail/receiver_of.hpp
index dc0be306..b2901ce9 100644
--- a/include/beman/execution/detail/receiver_of.hpp
+++ b/include/beman/execution/detail/receiver_of.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Receiver, typename Completions>
+template <typename Receiver, typename Completions>
 concept receiver_of =
     beman::execution::receiver<Receiver> && beman::execution::detail::has_completions<Receiver, Completions>;
 }
diff --git a/include/beman/execution/detail/run_loop.hpp b/include/beman/execution/detail/run_loop.hpp
index 2799ff0f..37a57559 100644
--- a/include/beman/execution/detail/run_loop.hpp
+++ b/include/beman/execution/detail/run_loop.hpp
@@ -26,7 +26,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT class run_loop {
+class run_loop {
   private:
     struct scheduler;
 
diff --git a/include/beman/execution/detail/schedule.hpp b/include/beman/execution/detail/schedule.hpp
index 25e54591..150596a6 100644
--- a/include/beman/execution/detail/schedule.hpp
+++ b/include/beman/execution/detail/schedule.hpp
@@ -13,7 +13,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct schedule_t {
+struct schedule_t {
     template <typename Scheduler>
         requires(not requires(Scheduler&& sched) {
                     { ::std::forward<Scheduler>(sched).schedule() } -> ::beman::execution::sender;
@@ -30,7 +30,7 @@ BEMAN_EXECUTION_EXPORT struct schedule_t {
     }
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::schedule_t schedule{};
+inline constexpr ::beman::execution::schedule_t schedule{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/schedule_from.hpp b/include/beman/execution/detail/schedule_from.hpp
index f2b7cdcb..64de4d2d 100644
--- a/include/beman/execution/detail/schedule_from.hpp
+++ b/include/beman/execution/detail/schedule_from.hpp
@@ -191,8 +191,8 @@ struct completion_signatures_for_impl<
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using schedule_from_t = beman::execution::detail::schedule_from_t;
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::schedule_from_t schedule_from{};
+using schedule_from_t = beman::execution::detail::schedule_from_t;
+inline constexpr ::beman::execution::schedule_from_t schedule_from{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/schedule_result_t.hpp b/include/beman/execution/detail/schedule_result_t.hpp
index 1f7b7a88..6b5d26b0 100644
--- a/include/beman/execution/detail/schedule_result_t.hpp
+++ b/include/beman/execution/detail/schedule_result_t.hpp
@@ -12,7 +12,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <::beman::execution::scheduler Scheduler>
+template <::beman::execution::scheduler Scheduler>
 using schedule_result_t = decltype(::beman::execution::schedule(::std::declval<Scheduler>()));
 }
 
diff --git a/include/beman/execution/detail/scheduler.hpp b/include/beman/execution/detail/scheduler.hpp
index 71ae0bc8..8dbadbae 100644
--- a/include/beman/execution/detail/scheduler.hpp
+++ b/include/beman/execution/detail/scheduler.hpp
@@ -17,7 +17,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Scheduler>
+template <typename Scheduler>
 concept scheduler = ::beman::execution::detail::almost_scheduler<Scheduler> && requires(Scheduler&& sched) {
     {
         ::beman::execution::get_completion_scheduler<::beman::execution::set_value_t>(
diff --git a/include/beman/execution/detail/scheduler_t.hpp b/include/beman/execution/detail/scheduler_t.hpp
index 2765f271..45b415cd 100644
--- a/include/beman/execution/detail/scheduler_t.hpp
+++ b/include/beman/execution/detail/scheduler_t.hpp
@@ -13,7 +13,7 @@ namespace beman::execution {
  * \brief Tag type to indicate a class is a scheduler.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT struct scheduler_t {};
+struct scheduler_t {};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/scope_token.hpp b/include/beman/execution/detail/scope_token.hpp
index 1e5b0fe6..7ace3ca3 100644
--- a/include/beman/execution/detail/scope_token.hpp
+++ b/include/beman/execution/detail/scope_token.hpp
@@ -29,7 +29,7 @@ static_assert(::beman::execution::sender_in<::beman::execution::detail::token_te
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Token>
+template <typename Token>
 concept scope_token = ::std::copyable<Token> && requires(Token token) {
     { token.try_associate() } -> ::std::same_as<bool>;
     { token.disassociate() } noexcept;
diff --git a/include/beman/execution/detail/sender.hpp b/include/beman/execution/detail/sender.hpp
index 1633d1fc..746459e8 100644
--- a/include/beman/execution/detail/sender.hpp
+++ b/include/beman/execution/detail/sender.hpp
@@ -16,7 +16,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct sender_t {};
+struct sender_t {};
 } // namespace beman::execution
 namespace beman::execution::detail {
 template <typename Sender>
@@ -29,7 +29,7 @@ concept enable_sender =
                                              ::beman::execution::detail::env_promise<::beman::execution::env<>>>;
 } // namespace beman::execution::detail
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Sender>
+template <typename Sender>
 concept sender = ::beman::execution::detail::enable_sender<::std::remove_cvref_t<Sender>> &&
                  requires(const ::std::remove_cvref_t<Sender>& sndr) {
                      { ::beman::execution::get_env(sndr) } -> ::beman::execution::detail::queryable;
diff --git a/include/beman/execution/detail/sender_adaptor.hpp b/include/beman/execution/detail/sender_adaptor.hpp
index a23d3bdc..97f29061 100644
--- a/include/beman/execution/detail/sender_adaptor.hpp
+++ b/include/beman/execution/detail/sender_adaptor.hpp
@@ -16,7 +16,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution::detail {
-BEMAN_EXECUTION_EXPORT template <typename Adaptor, typename... T> //-dk:TODO detail export
+template <typename Adaptor, typename... T> //-dk:TODO detail export
 struct sender_adaptor : ::beman::execution::detail::product_type<::std::decay_t<Adaptor>, ::std::decay_t<T>...>,
                         ::beman::execution::sender_adaptor_closure<sender_adaptor<Adaptor, T...>> {
     template <::beman::execution::sender Sender, typename Self>
diff --git a/include/beman/execution/detail/sender_adaptor_closure.hpp b/include/beman/execution/detail/sender_adaptor_closure.hpp
index 1974093c..1018f4de 100644
--- a/include/beman/execution/detail/sender_adaptor_closure.hpp
+++ b/include/beman/execution/detail/sender_adaptor_closure.hpp
@@ -18,7 +18,7 @@ struct sender_adaptor_closure_base {};
 
 namespace beman::execution {
 // NOLINTBEGIN(bugprone-crtp-constructor-accessibility)
-BEMAN_EXECUTION_EXPORT template <typename>
+template <typename>
 struct sender_adaptor_closure : ::beman::execution::detail::pipeable::sender_adaptor_closure_base {};
 // NOLINTEND(bugprone-crtp-constructor-accessibility)
 
@@ -31,7 +31,7 @@ concept is_sender_adaptor_closure =
 }
 
 namespace beman::execution::detail::pipeable {
-BEMAN_EXECUTION_EXPORT template <::beman::execution::sender Sender, typename Adaptor>
+template <::beman::execution::sender Sender, typename Adaptor>
     requires(!::beman::execution::sender<Adaptor>) &&
             ::std::derived_from<::std::decay_t<Adaptor>,
                                 ::beman::execution::sender_adaptor_closure<::std::decay_t<Adaptor>>> &&
diff --git a/include/beman/execution/detail/sender_in.hpp b/include/beman/execution/detail/sender_in.hpp
index b2f2957f..74f158a8 100644
--- a/include/beman/execution/detail/sender_in.hpp
+++ b/include/beman/execution/detail/sender_in.hpp
@@ -14,7 +14,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Sender, typename Env = ::beman::execution::env<>>
+template <typename Sender, typename Env = ::beman::execution::env<>>
 concept sender_in =
     ::beman::execution::sender<Sender> && ::beman::execution::detail::queryable<Env> &&
     requires(Sender&& sender, Env&& env) {
diff --git a/include/beman/execution/detail/sends_stopped.hpp b/include/beman/execution/detail/sends_stopped.hpp
index 56a0bf82..ae88a299 100644
--- a/include/beman/execution/detail/sends_stopped.hpp
+++ b/include/beman/execution/detail/sends_stopped.hpp
@@ -16,7 +16,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Sender, typename Env = ::beman::execution::env<>>
+template <typename Sender, typename Env = ::beman::execution::env<>>
     requires ::beman::execution::sender_in<Sender, Env>
 inline constexpr bool sends_stopped{!::std::same_as<
     ::beman::execution::detail::type_list<>,
diff --git a/include/beman/execution/detail/set_error.hpp b/include/beman/execution/detail/set_error.hpp
index bd00fc45..9f54268d 100644
--- a/include/beman/execution/detail/set_error.hpp
+++ b/include/beman/execution/detail/set_error.hpp
@@ -16,7 +16,7 @@ namespace beman::execution {
  * \brief Type of the customization point object for error completions.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT struct set_error_t {
+struct set_error_t {
     template <typename Receiver, typename Error>
     auto operator()(Receiver&, Error&&) const
         -> void = BEMAN_EXECUTION_DELETE("set_error requires the receiver to be passed as non-const rvalue");
@@ -46,7 +46,7 @@ BEMAN_EXECUTION_EXPORT struct set_error_t {
  * \brief Customization point object for error completions.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr set_error_t set_error{};
+inline constexpr set_error_t set_error{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/set_stopped.hpp b/include/beman/execution/detail/set_stopped.hpp
index 43a68d33..12cc38cc 100644
--- a/include/beman/execution/detail/set_stopped.hpp
+++ b/include/beman/execution/detail/set_stopped.hpp
@@ -16,7 +16,7 @@ namespace beman::execution {
  * \brief Type of the customization point object for cancellation completions.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT struct set_stopped_t {
+struct set_stopped_t {
     template <typename Receiver>
     auto operator()(Receiver&) const
         -> void = BEMAN_EXECUTION_DELETE("set_stopped requires the receiver to be passed as non-const rvalue");
@@ -42,7 +42,7 @@ BEMAN_EXECUTION_EXPORT struct set_stopped_t {
  * \brief Customization point object for cancellation completions.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr set_stopped_t set_stopped{};
+inline constexpr set_stopped_t set_stopped{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/set_value.hpp b/include/beman/execution/detail/set_value.hpp
index 30dd8bbf..0abd506c 100644
--- a/include/beman/execution/detail/set_value.hpp
+++ b/include/beman/execution/detail/set_value.hpp
@@ -16,7 +16,7 @@ namespace beman::execution {
  * \brief Type of the customization point object for successful completions.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT struct set_value_t {
+struct set_value_t {
     template <typename Receiver, typename... Args>
     auto operator()(Receiver&, Args&&...) const
         -> void = BEMAN_EXECUTION_DELETE("set_value requires the receiver to be passed as non-const rvalue");
@@ -44,7 +44,7 @@ BEMAN_EXECUTION_EXPORT struct set_value_t {
  * \brief Customization point object for successful completions.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr set_value_t set_value{};
+inline constexpr set_value_t set_value{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/simple_allocator.hpp b/include/beman/execution/detail/simple_allocator.hpp
index eab53f60..ca806273 100644
--- a/include/beman/execution/detail/simple_allocator.hpp
+++ b/include/beman/execution/detail/simple_allocator.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution::detail {
-BEMAN_EXECUTION_EXPORT template <typename Alloc> //-dk:TODO detail export
+template <typename Alloc> //-dk:TODO detail export
 concept simple_allocator =
     requires(::std::remove_cvref_t<Alloc> alloc, ::std::size_t n) {
         { *alloc.allocate(n) } -> ::std::same_as<typename ::std::remove_cvref_t<Alloc>::value_type&>;
diff --git a/include/beman/execution/detail/simple_counting_scope.hpp b/include/beman/execution/detail/simple_counting_scope.hpp
index 1a5d1269..ddad87aa 100644
--- a/include/beman/execution/detail/simple_counting_scope.hpp
+++ b/include/beman/execution/detail/simple_counting_scope.hpp
@@ -14,7 +14,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT class simple_counting_scope;
+class simple_counting_scope;
 }
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/spawn.hpp b/include/beman/execution/detail/spawn.hpp
index ae4b6ecc..fd058303 100644
--- a/include/beman/execution/detail/spawn.hpp
+++ b/include/beman/execution/detail/spawn.hpp
@@ -85,8 +85,8 @@ struct spawn_t {
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using spawn_t = ::beman::execution::detail::spawn_t;
-BEMAN_EXECUTION_EXPORT inline constexpr spawn_t spawn{};
+using spawn_t = ::beman::execution::detail::spawn_t;
+inline constexpr spawn_t spawn{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/spawn_future.hpp b/include/beman/execution/detail/spawn_future.hpp
index 86f36ce8..e3f8d646 100644
--- a/include/beman/execution/detail/spawn_future.hpp
+++ b/include/beman/execution/detail/spawn_future.hpp
@@ -262,8 +262,8 @@ struct impls_for<spawn_future_t> : ::beman::execution::detail::default_impls {
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using spawn_future_t = ::beman::execution::detail::spawn_future_t;
-BEMAN_EXECUTION_EXPORT inline constexpr spawn_future_t spawn_future{};
+using spawn_future_t = ::beman::execution::detail::spawn_future_t;
+inline constexpr spawn_future_t spawn_future{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/split.hpp b/include/beman/execution/detail/split.hpp
index 150f1880..cbf4e67f 100644
--- a/include/beman/execution/detail/split.hpp
+++ b/include/beman/execution/detail/split.hpp
@@ -381,9 +381,9 @@ struct completion_signatures_for_impl<
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using split_t = ::beman::execution::detail::split_t;
+using split_t = ::beman::execution::detail::split_t;
 
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::split_t split{};
+inline constexpr ::beman::execution::split_t split{};
 } // namespace beman::execution
 
 #endif // INCLUDED_BEMAN_EXECUTION_DETAIL_SPLIT
diff --git a/include/beman/execution/detail/start.hpp b/include/beman/execution/detail/start.hpp
index 9e62737a..06029f07 100644
--- a/include/beman/execution/detail/start.hpp
+++ b/include/beman/execution/detail/start.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT struct start_t {
+struct start_t {
     template <typename State>
     auto operator()(State&&) const -> void = BEMAN_EXECUTION_DELETE("start(obj) requires an lvalue argument");
     template <typename State>
@@ -44,7 +44,7 @@ BEMAN_EXECUTION_EXPORT struct start_t {
     // NOLINTEND(misc-no-recursion)
 };
 
-BEMAN_EXECUTION_EXPORT inline constexpr start_t start{};
+inline constexpr start_t start{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/starts_on.hpp b/include/beman/execution/detail/starts_on.hpp
index 1a09d71a..381dfab9 100644
--- a/include/beman/execution/detail/starts_on.hpp
+++ b/include/beman/execution/detail/starts_on.hpp
@@ -54,8 +54,8 @@ struct starts_on_t {
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using starts_on_t = ::beman::execution::detail::starts_on_t;
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::detail::starts_on_t starts_on{};
+using starts_on_t = ::beman::execution::detail::starts_on_t;
+inline constexpr ::beman::execution::detail::starts_on_t starts_on{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/stop_callback_for_t.hpp b/include/beman/execution/detail/stop_callback_for_t.hpp
index 9b658149..65233aca 100644
--- a/include/beman/execution/detail/stop_callback_for_t.hpp
+++ b/include/beman/execution/detail/stop_callback_for_t.hpp
@@ -10,7 +10,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <class Token, class CallbackFun>
+template <class Token, class CallbackFun>
 using stop_callback_for_t = typename Token::template callback_type<CallbackFun>;
 }
 
diff --git a/include/beman/execution/detail/stop_source.hpp b/include/beman/execution/detail/stop_source.hpp
index d24752a6..cc7d59f2 100644
--- a/include/beman/execution/detail/stop_source.hpp
+++ b/include/beman/execution/detail/stop_source.hpp
@@ -16,11 +16,11 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT class stop_token;
-BEMAN_EXECUTION_EXPORT class stop_source;
-BEMAN_EXECUTION_EXPORT template <typename CallbackFun>
+class stop_token;
+class stop_source;
+template <typename CallbackFun>
 class stop_callback;
-BEMAN_EXECUTION_EXPORT template <typename CallbackFun>
+template <typename CallbackFun>
 stop_callback(::beman::execution::stop_token, CallbackFun) -> stop_callback<CallbackFun>;
 } // namespace beman::execution
 
diff --git a/include/beman/execution/detail/stop_token_of_t.hpp b/include/beman/execution/detail/stop_token_of_t.hpp
index cb2ea4e5..263bade5 100644
--- a/include/beman/execution/detail/stop_token_of_t.hpp
+++ b/include/beman/execution/detail/stop_token_of_t.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename T>
+template <typename T>
 using stop_token_of_t = ::std::remove_cvref_t<decltype(::beman::execution::get_stop_token(::std::declval<T>()))>;
 }
 
diff --git a/include/beman/execution/detail/stoppable_source.hpp b/include/beman/execution/detail/stoppable_source.hpp
index 3bad57a7..b75f0582 100644
--- a/include/beman/execution/detail/stoppable_source.hpp
+++ b/include/beman/execution/detail/stoppable_source.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution::detail {
-BEMAN_EXECUTION_EXPORT template <typename Source> //-dk:TODO detail export
+template <typename Source> //-dk:TODO detail export
 concept stoppable_source = requires(Source& source, const Source& csource) {
     { csource.get_token() } -> ::beman::execution::stoppable_token;
     { csource.stop_possible() } noexcept -> ::std::same_as<bool>;
diff --git a/include/beman/execution/detail/stoppable_token.hpp b/include/beman/execution/detail/stoppable_token.hpp
index ac2f0add..ac737cd5 100644
--- a/include/beman/execution/detail/stoppable_token.hpp
+++ b/include/beman/execution/detail/stoppable_token.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Token>
+template <typename Token>
 concept stoppable_token = requires(const Token& token) {
     typename ::beman::execution::detail::check_type_alias_exist<Token::template callback_type>;
     { token.stop_requested() } noexcept -> ::std::same_as<bool>;
diff --git a/include/beman/execution/detail/sync_wait.hpp b/include/beman/execution/detail/sync_wait.hpp
index ffceee6b..698bd95e 100644
--- a/include/beman/execution/detail/sync_wait.hpp
+++ b/include/beman/execution/detail/sync_wait.hpp
@@ -26,22 +26,21 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution::detail {
-BEMAN_EXECUTION_EXPORT struct sync_wait_env { // dk:TODO detail export
+struct sync_wait_env { // dk:TODO detail export
     ::beman::execution::run_loop* loop{};
 
     auto query(::beman::execution::get_scheduler_t) const noexcept { return this->loop->get_scheduler(); }
     auto query(::beman::execution::get_delegation_scheduler_t) const noexcept { return this->loop->get_scheduler(); }
 };
 
-BEMAN_EXECUTION_EXPORT template <
-    ::beman::execution::sender_in<::beman::execution::detail::sync_wait_env> Sender> // dk:TODO detail export
+template <::beman::execution::sender_in<::beman::execution::detail::sync_wait_env> Sender> // dk:TODO detail export
 using sync_wait_result_type =
     ::std::optional<::beman::execution::value_types_of_t<Sender,
                                                          ::beman::execution::detail::sync_wait_env,
                                                          ::beman::execution::detail::decayed_tuple,
                                                          ::std::type_identity_t>>;
 
-BEMAN_EXECUTION_EXPORT template <typename Sender> // dk:TODO detail export
+template <typename Sender> // dk:TODO detail export
 struct sync_wait_state {
     ::beman::execution::run_loop loop{};
     ::std::exception_ptr         error{};
@@ -49,7 +48,7 @@ struct sync_wait_state {
     ::beman::execution::detail::sync_wait_result_type<Sender> result{};
 };
 
-BEMAN_EXECUTION_EXPORT template <typename Sender> // dk:TODO detail export
+template <typename Sender> // dk:TODO detail export
 struct sync_wait_receiver {
     using receiver_concept = ::beman::execution::receiver_t;
 
@@ -109,7 +108,7 @@ struct sync_wait_t {
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using sync_wait_t = ::beman::execution::detail::sync_wait_t;
+using sync_wait_t = ::beman::execution::detail::sync_wait_t;
 /*!
  * \brief <code>sync_wait(_sender_)</code> starts <code>_sender_</code> and waits for its completion.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
@@ -157,7 +156,7 @@ BEMAN_EXECUTION_EXPORT using sync_wait_t = ::beman::execution::detail::sync_wait
  * }
  * </pre>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::sync_wait_t sync_wait{};
+inline constexpr ::beman::execution::sync_wait_t sync_wait{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/tag_of_t.hpp b/include/beman/execution/detail/tag_of_t.hpp
index 7a83c2fb..166ee288 100644
--- a/include/beman/execution/detail/tag_of_t.hpp
+++ b/include/beman/execution/detail/tag_of_t.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Sender>
+template <typename Sender>
 using tag_of_t = typename decltype(::beman::execution::detail::get_sender_meta(::std::declval<Sender&&>()))::tag_type;
 }
 
diff --git a/include/beman/execution/detail/then.hpp b/include/beman/execution/detail/then.hpp
index af24f68a..c8b9db80 100644
--- a/include/beman/execution/detail/then.hpp
+++ b/include/beman/execution/detail/then.hpp
@@ -153,17 +153,17 @@ namespace beman::execution {
  * \brief <code>then_t</code> is the type of <code>then</code>.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT using then_t = ::beman::execution::detail::then_t<::beman::execution::set_value_t>;
+using then_t = ::beman::execution::detail::then_t<::beman::execution::set_value_t>;
 /*!
  * \brief <code>upon_error_t</code> is the type of <code>upon_error</code>.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT using upon_error_t = ::beman::execution::detail::then_t<::beman::execution::set_error_t>;
+using upon_error_t = ::beman::execution::detail::then_t<::beman::execution::set_error_t>;
 /*!
  * \brief <code>upon_stopped_t</code> is the type of <code>upon_stopped</code>.
  * \headerfile beman/execution/execution.hpp <beman/execution/execution.hpp>
  */
-BEMAN_EXECUTION_EXPORT using upon_stopped_t = ::beman::execution::detail::then_t<::beman::execution::set_stopped_t>;
+using upon_stopped_t = ::beman::execution::detail::then_t<::beman::execution::set_stopped_t>;
 
 /*!
  * \brief <code>then(_sender_, _fun_)</code> yields a sender transforming a <code>set_value_t(_A_...)</code> completion
@@ -215,7 +215,7 @@ BEMAN_EXECUTION_EXPORT using upon_stopped_t = ::beman::execution::detail::then_t
  * }
  * </pre>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::then_t then{};
+inline constexpr ::beman::execution::then_t then{};
 
 /*!
  * \brief <code>upon_error(_sender_, _fun_)</code> yields a sender transforming a <code>set_error_t(_E_)</code>
@@ -269,7 +269,7 @@ BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::then_t then{};
  * }
  * </pre>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::upon_error_t upon_error{};
+inline constexpr ::beman::execution::upon_error_t upon_error{};
 
 /*!
  * \brief <code>upon_stopped(_sender_, _fun_)</code> yields a sender transforming a <code>set_stopped_t()</code>
@@ -320,7 +320,7 @@ BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::upon_error_t upon_er
  * }
  * </pre>
  */
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::upon_stopped_t upon_stopped{};
+inline constexpr ::beman::execution::upon_stopped_t upon_stopped{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/transform_sender.hpp b/include/beman/execution/detail/transform_sender.hpp
index 10ec17d4..c7ca9bb3 100644
--- a/include/beman/execution/detail/transform_sender.hpp
+++ b/include/beman/execution/detail/transform_sender.hpp
@@ -66,7 +66,7 @@ constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env)
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+template <typename Domain, ::beman::execution::sender Sender, typename... Env>
     requires(sizeof...(Env) < 2) &&
             requires(Domain dom, Sender&& sender, const Env&... env) {
                 dom.transform_sender(::std::forward<Sender>(sender), env...);
@@ -79,7 +79,7 @@ constexpr auto transform_sender(Domain, Sender&& sender, const Env&...) noexcept
     return ::std::forward<Sender>(sender);
 }
 
-BEMAN_EXECUTION_EXPORT template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+template <typename Domain, ::beman::execution::sender Sender, typename... Env>
     requires(sizeof...(Env) < 2) &&
             requires(Domain dom, Sender&& sender, const Env&... env) {
                 dom.transform_sender(::std::forward<Sender>(sender), env...);
@@ -93,7 +93,7 @@ constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env)
         dom, dom.transform_sender(::std::forward<Sender>(sender), env...), env...);
 }
 
-BEMAN_EXECUTION_EXPORT template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+template <typename Domain, ::beman::execution::sender Sender, typename... Env>
     requires(sizeof...(Env) < 2) && (not requires(Domain dom, Sender&& sender, const Env&... env) {
                 dom.transform_sender(::std::forward<Sender>(sender), env...);
             }) &&
@@ -106,7 +106,7 @@ constexpr auto
     return ::std::forward<Sender>(sender);
 }
 
-BEMAN_EXECUTION_EXPORT template <typename Domain, ::beman::execution::sender Sender, typename... Env>
+template <typename Domain, ::beman::execution::sender Sender, typename... Env>
     requires(sizeof...(Env) < 2) && (not requires(Domain dom, Sender&& sender, const Env&... env) {
                 dom.transform_sender(::std::forward<Sender>(sender), env...);
             }) &&
diff --git a/include/beman/execution/detail/unstoppable_token.hpp b/include/beman/execution/detail/unstoppable_token.hpp
index b1d4bc97..75c9e561 100644
--- a/include/beman/execution/detail/unstoppable_token.hpp
+++ b/include/beman/execution/detail/unstoppable_token.hpp
@@ -11,7 +11,7 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Token>
+template <typename Token>
 concept unstoppable_token = ::beman::execution::stoppable_token<Token> &&
                             requires() { requires ::std::bool_constant<not Token::stop_possible()>::value; };
 } // namespace beman::execution
diff --git a/include/beman/execution/detail/valid_completion_for.hpp b/include/beman/execution/detail/valid_completion_for.hpp
index 9b69b057..24048377 100644
--- a/include/beman/execution/detail/valid_completion_for.hpp
+++ b/include/beman/execution/detail/valid_completion_for.hpp
@@ -24,7 +24,7 @@ struct valid_completion_for_aux<Rcvr, Tag (*)(Args...)> {
     {}
 };
 
-BEMAN_EXECUTION_EXPORT template <typename Signature, typename Rcvr> // dk:TODO detail export
+template <typename Signature, typename Rcvr> // dk:TODO detail export
 concept valid_completion_for = requires(Signature* signature) {
 #if 1
     valid_completion_for_aux<Rcvr, Signature*>::test(signature);
diff --git a/include/beman/execution/detail/value_types_of_t.hpp b/include/beman/execution/detail/value_types_of_t.hpp
index 1c279184..eb5508d7 100644
--- a/include/beman/execution/detail/value_types_of_t.hpp
+++ b/include/beman/execution/detail/value_types_of_t.hpp
@@ -15,10 +15,10 @@
 // ----------------------------------------------------------------------------
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <typename Sender,
-                                 typename Env                         = ::beman::execution::env<>,
-                                 template <typename...> class Tuple   = ::beman::execution::detail::decayed_tuple,
-                                 template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
+template <typename Sender,
+          typename Env                         = ::beman::execution::env<>,
+          template <typename...> class Tuple   = ::beman::execution::detail::decayed_tuple,
+          template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
     requires ::beman::execution::sender_in<Sender, Env>
 using value_types_of_t =
     ::beman::execution::detail::gather_signatures<::beman::execution::set_value_t,
diff --git a/include/beman/execution/detail/when_all.hpp b/include/beman/execution/detail/when_all.hpp
index 47f1474b..fe74a6d2 100644
--- a/include/beman/execution/detail/when_all.hpp
+++ b/include/beman/execution/detail/when_all.hpp
@@ -276,8 +276,8 @@ struct completion_signatures_for_impl<
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using when_all_t = ::beman::execution::detail::when_all_t;
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::when_all_t when_all{};
+using when_all_t = ::beman::execution::detail::when_all_t;
+inline constexpr ::beman::execution::when_all_t when_all{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/when_all_with_variant.hpp b/include/beman/execution/detail/when_all_with_variant.hpp
index 5a37adc9..5d1882f8 100644
--- a/include/beman/execution/detail/when_all_with_variant.hpp
+++ b/include/beman/execution/detail/when_all_with_variant.hpp
@@ -41,8 +41,8 @@ struct when_all_with_variant_t {
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using when_all_with_variant_t = ::beman::execution::detail::when_all_with_variant_t;
-BEMAN_EXECUTION_EXPORT inline constexpr ::beman::execution::when_all_with_variant_t when_all_with_variant{};
+using when_all_with_variant_t = ::beman::execution::detail::when_all_with_variant_t;
+inline constexpr ::beman::execution::when_all_with_variant_t when_all_with_variant{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/include/beman/execution/detail/with_awaitable_senders.hpp b/include/beman/execution/detail/with_awaitable_senders.hpp
index a744a3dc..c9b2610a 100644
--- a/include/beman/execution/detail/with_awaitable_senders.hpp
+++ b/include/beman/execution/detail/with_awaitable_senders.hpp
@@ -12,7 +12,7 @@
 #include <coroutine>
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT template <::beman::execution::detail::class_type Promise>
+template <::beman::execution::detail::class_type Promise>
 struct with_awaitable_senders {
     template <class OtherPromise>
         requires(!::std::same_as<OtherPromise, void>)
diff --git a/include/beman/execution/detail/write_env.hpp b/include/beman/execution/detail/write_env.hpp
index 3b5c2d67..c55dae1d 100644
--- a/include/beman/execution/detail/write_env.hpp
+++ b/include/beman/execution/detail/write_env.hpp
@@ -56,8 +56,8 @@ inline constexpr write_env_t write_env{};
 } // namespace beman::execution::detail
 
 namespace beman::execution {
-BEMAN_EXECUTION_EXPORT using write_env_t = ::beman::execution::detail::write_env_t;
-BEMAN_EXECUTION_EXPORT inline constexpr write_env_t write_env{};
+using write_env_t = ::beman::execution::detail::write_env_t;
+inline constexpr write_env_t write_env{};
 } // namespace beman::execution
 
 // ----------------------------------------------------------------------------
diff --git a/src/beman/execution/CMakeLists.txt b/src/beman/execution/CMakeLists.txt
index ebd7bdf6..10774bac 100644
--- a/src/beman/execution/CMakeLists.txt
+++ b/src/beman/execution/CMakeLists.txt
@@ -201,7 +201,7 @@ if(BEMAN_USE_MODULES)
         PUBLIC
             FILE_SET CXX_MODULES
                 BASE_DIRS ${PROJECT_SOURCE_DIR}/src/beman/execution
-                FILES ${PROJECT_SOURCE_DIR}/src/beman/execution/execution-using.cppm
+                FILES ${PROJECT_SOURCE_DIR}/src/beman/execution/execution.cppm
     )
     target_link_libraries(${TARGET_PREFIX} PUBLIC ${TARGET_NAME})
 endif()
diff --git a/src/beman/execution/execution-using.cppm b/src/beman/execution/execution-using.cppm
deleted file mode 100644
index 5ff6ed6a..00000000
--- a/src/beman/execution/execution-using.cppm
+++ /dev/null
@@ -1,258 +0,0 @@
-module;
-// src/beman/execution/execution-using.cppm
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-
-#include <beman/execution/execution.hpp>
-#include <beman/execution/stop_token.hpp>
-
-export module beman.execution;
-
-namespace beman::execution {
-export using beman::execution::detail::pipeable::operator|;
-
-// [stoptoken.concepts], stop token concepts
-export using ::beman::execution::stoppable_token;
-export using ::beman::execution::unstoppable_token;
-
-// [stoptoken], class stop_token
-export using ::beman::execution::stop_token;
-
-// [stopsource], class stop_source
-export using ::beman::execution::stop_source;
-
-export using ::beman::execution::nostopstate_t;
-export using ::beman::execution::nostopstate;
-
-// [stopcallback], class template stop_callback
-export using ::beman::execution::stop_callback;
-
-// [stoptoken.never], class never_stop_token
-export using ::beman::execution::never_stop_token;
-
-// [stoptoken.inplace], class inplace_stop_token
-export using ::beman::execution::inplace_stop_token;
-
-// [stopsource.inplace], class inplace_stop_source
-export using ::beman::execution::inplace_stop_source;
-
-// [stopcallback.inplace], class template inplace_stop_callback
-export using ::beman::execution::inplace_stop_callback;
-export using ::beman::execution::stop_callback_for_t;
-
-#if 0
-    //-dk:TODO enable the execution policies
-    export using ::std::is_execution_policy;
-    export using ::std::is_execution_policy_v;
-
-    export using ::std::execution::sequenced_policy;
-    export using ::std::execution::parallel_policy;
-    export using ::std::execution::parallel_unsequenced_policy;
-    export using ::std::execution::unsequenced_policy;
-
-    export using ::std::execution::seq;
-    export using ::std::execution::par;
-    export using ::std::execution::par_unseq;
-    export using ::std::execution::unseq;
-#endif
-
-// [exec.queries], queries
-export using ::beman::execution::forwarding_query_t;
-export using ::beman::execution::get_allocator_t;
-export using ::beman::execution::get_stop_token_t;
-
-export using ::beman::execution::forwarding_query;
-export using ::beman::execution::get_allocator;
-export using ::beman::execution::get_stop_token;
-
-export using ::beman::execution::stop_token_of_t;
-
-export using ::beman::execution::get_domain_t;
-export using ::beman::execution::get_scheduler_t;
-export using ::beman::execution::get_delegation_scheduler_t;
-//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee_t;
-export using ::beman::execution::get_completion_scheduler_t;
-
-export using ::beman::execution::get_domain;
-export using ::beman::execution::get_scheduler;
-export using ::beman::execution::get_delegation_scheduler;
-//-dk:TODO export using ::beman::execution::forward_progress_guarantee;
-//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee;
-export using ::beman::execution::get_completion_scheduler;
-
-export using ::beman::execution::env;
-export using ::beman::execution::get_env_t;
-export using ::beman::execution::get_env;
-
-export using ::beman::execution::env_of_t;
-
-// [exec.domain.default], execution_domains
-export using ::beman::execution::default_domain;
-
-// [exec.sched], schedulers
-export using ::beman::execution::scheduler_t;
-export using ::beman::execution::scheduler;
-
-// [exec.recv], receivers
-export using ::beman::execution::receiver_t;
-export using ::beman::execution::receiver;
-export using ::beman::execution::receiver_of;
-
-export using ::beman::execution::set_value_t;
-export using ::beman::execution::set_error_t;
-export using ::beman::execution::set_stopped_t;
-
-export using ::beman::execution::set_value;
-export using ::beman::execution::set_error;
-export using ::beman::execution::set_stopped;
-
-// [exec.opstate], operation states
-export using ::beman::execution::operation_state_t;
-export using ::beman::execution::operation_state;
-export using ::beman::execution::start_t;
-export using ::beman::execution::start;
-
-// [exec.snd], senders
-export using ::beman::execution::sender_t;
-export using ::beman::execution::sender;
-export using ::beman::execution::sender_in;
-//-dk:TODO export using ::beman::execution::sender_to;
-
-// [exec.getcomplsigs], completion signatures
-export using ::beman::execution::get_completion_signatures_t;
-export using ::beman::execution::get_completion_signatures;
-export using ::beman::execution::completion_signatures_of_t;
-export using ::beman::execution::value_types_of_t;
-export using ::beman::execution::error_types_of_t;
-export using ::beman::execution::sends_stopped;
-export using ::beman::execution::tag_of_t;
-
-// [exec.snd.transform], sender transformations
-export using ::beman::execution::transform_sender;
-
-// [exec.snd.transform.env], environment transformations
-//-dk:TODO export using ::beman::execution::transform_env;
-
-// [exec.snd.apply], sender algorithm application
-export using ::beman::execution::apply_sender;
-
-// [exec.connect], the connect sender algorithm
-export using ::beman::execution::connect_t;
-export using ::beman::execution::connect;
-export using ::beman::execution::connect_result_t;
-
-// [exec.factories], sender factories
-export using ::beman::execution::just_t;
-export using ::beman::execution::just_error_t;
-export using ::beman::execution::just_stopped_t;
-export using ::beman::execution::schedule_t;
-
-export using ::beman::execution::just;
-export using ::beman::execution::just_error;
-export using ::beman::execution::just_stopped;
-export using ::beman::execution::schedule;
-export using ::beman::execution::read_env;
-
-export using ::beman::execution::schedule_result_t;
-
-// [exec.adapt], sender adaptors
-export using ::beman::execution::sender_adaptor_closure;
-
-export using ::beman::execution::starts_on_t;
-export using ::beman::execution::continues_on_t;
-export using ::beman::execution::on_t;
-export using ::beman::execution::schedule_from_t;
-export using ::beman::execution::then_t;
-export using ::beman::execution::upon_error_t;
-export using ::beman::execution::upon_stopped_t;
-export using ::beman::execution::let_value_t;
-export using ::beman::execution::let_error_t;
-export using ::beman::execution::let_stopped_t;
-export using ::beman::execution::bulk_t;
-export using ::beman::execution::split_t;
-export using ::beman::execution::when_all_t;
-export using ::beman::execution::when_all_with_variant_t;
-export using ::beman::execution::into_variant_t;
-//-dk:TODO export using ::beman::execution::stopped_as_optional_t;
-//-dk:TODO export using ::beman::execution::stopped_as_error_t;
-
-export using ::beman::execution::starts_on;
-export using ::beman::execution::continues_on;
-export using ::beman::execution::on;
-export using ::beman::execution::schedule_from;
-export using ::beman::execution::then;
-export using ::beman::execution::upon_error;
-export using ::beman::execution::upon_stopped;
-export using ::beman::execution::let_value;
-export using ::beman::execution::let_error;
-export using ::beman::execution::let_stopped;
-export using ::beman::execution::bulk;
-export using ::beman::execution::split;
-export using ::beman::execution::when_all;
-export using ::beman::execution::when_all_with_variant;
-export using ::beman::execution::into_variant;
-//-dk:TODO export using ::beman::execution::stopped_as_optional;
-//-dk:TODO export using ::beman::execution::stopped_as_error;
-
-// [exec.util.cmplsig]
-export using ::beman::execution::completion_signatures;
-
-// [exec.util.cmplsig.trans]
-//-dk:TODO export using ::beman::execution::transform_completion_signatures;
-//-dk:TODO export using ::beman::execution::transform_completion_signatures_of;
-
-// [exec.run.loop], run_loop
-export using ::beman::execution::run_loop;
-
-// [exec.consumers], consumers
-export using ::beman::execution::sync_wait_t;
-//-dk:TODO export using ::beman::execution::sync_wait_with_variant_t;
-
-export using ::beman::execution::sync_wait;
-//-dk:TODO export using ::beman::execution::sync_wait_with_variant;
-
-// [exec.as.awaitable]
-export using ::beman::execution::as_awaitable_t;
-export using ::beman::execution::as_awaitable;
-
-// [exec.with.awaitable.senders]
-export using ::beman::execution::with_awaitable_senders;
-
-//-dk:TODO add section
-export using ::beman::execution::prop;
-export using ::beman::execution::write_env_t;
-export using ::beman::execution::write_env;
-export using ::beman::execution::affine_on_t;
-export using ::beman::execution::affine_on;
-export using ::beman::execution::read_env_t;
-export using ::beman::execution::read_env;
-export using ::beman::execution::simple_counting_scope;
-export using ::beman::execution::counting_scope;
-export using ::beman::execution::scope_token;
-
-namespace detail {
-export using ::beman::execution::detail::basic_sender;
-export using ::beman::execution::detail::product_type;
-export using ::beman::execution::detail::product_type_base;
-export using ::beman::execution::detail::is_product_type_c;
-export using ::beman::execution::detail::env_promise;
-export using ::beman::execution::detail::await_result_type;
-export using ::beman::execution::detail::simple_allocator;
-export using ::beman::execution::detail::sync_wait_env;
-export using ::beman::execution::detail::sync_wait_result_type;
-export using ::beman::execution::detail::sync_wait_state;
-export using ::beman::execution::detail::sync_wait_receiver;
-export using ::beman::execution::detail::connect_all_t;
-export using ::beman::execution::detail::connect_all;
-} // namespace detail
-
-} // namespace beman::execution
-
-namespace std {
-export template <typename T>
-    requires ::beman::execution::detail::is_product_type_c<T>
-struct tuple_size<T>;
-
-export template <::std::size_t I, typename T>
-    requires ::beman::execution::detail::is_product_type_c<T>
-struct tuple_element<I, T>;
-} // namespace std
diff --git a/src/beman/execution/execution.cppm b/src/beman/execution/execution.cppm
index e54eb38a..5ff6ed6a 100644
--- a/src/beman/execution/execution.cppm
+++ b/src/beman/execution/execution.cppm
@@ -1,6472 +1,258 @@
 module;
+// src/beman/execution/execution-using.cppm
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// *****************************************************;
-// *** WARNING: this file is generated: do not edit! ***;
-// *****************************************************;
-// generated by ./bin/mk-module.py src/beman/execution/execution.cppm
 
-#include <beman/execution/modules_export.hpp>
-#include <cassert>
-
-#ifdef BEMAN_HAS_IMPORT_STD
-import std;
-#else
-#line 239 "./bin/mk-module.py"
-#include <algorithm>
-#line 239 "./bin/mk-module.py"
-#include <atomic>
-#line 239 "./bin/mk-module.py"
-#include <cassert>
-#line 239 "./bin/mk-module.py"
-#include <concepts>
-#line 239 "./bin/mk-module.py"
-#include <condition_variable>
-#line 239 "./bin/mk-module.py"
-#include <coroutine>
-#line 239 "./bin/mk-module.py"
-#include <cstddef>
-#line 239 "./bin/mk-module.py"
-#include <cstdlib>
-#line 239 "./bin/mk-module.py"
-#include <exception>
-#line 239 "./bin/mk-module.py"
-#include <functional>
-#line 239 "./bin/mk-module.py"
-#include <memory>
-#line 239 "./bin/mk-module.py"
-#include <mutex>
-#line 239 "./bin/mk-module.py"
-#include <optional>
-#line 239 "./bin/mk-module.py"
-#include <system_error>
-#line 239 "./bin/mk-module.py"
-#include <thread>
-#line 239 "./bin/mk-module.py"
-#include <tuple>
-#line 239 "./bin/mk-module.py"
-#include <type_traits>
-#line 239 "./bin/mk-module.py"
-#include <utility>
-#line 239 "./bin/mk-module.py"
-#include <variant>
-#endif
+#include <beman/execution/execution.hpp>
+#include <beman/execution/stop_token.hpp>
 
 export module beman.execution;
 
-#line 5 "include/beman/execution/execution.hpp"
-
-#line 9 "include/beman/execution/detail/common.hpp"
-#ifndef BEMAN_EXECUTION_EXPORT
-#define BEMAN_EXECUTION_EXPORT
-#endif
-
-#if defined(disabled__cpp_deleted_function)
-#define BEMAN_EXECUTION_DELETE(msg) delete (msg)
-#else
-#define BEMAN_EXECUTION_DELETE(msg) delete
-#endif
-
-#line 43 "include/beman/execution/detail/common.hpp"
-namespace beman {
-
-#line 54 "include/beman/execution/detail/common.hpp"
-namespace execution {
-
-#line 61 "include/beman/execution/detail/common.hpp"
-namespace detail {}
-} // namespace execution
-} // namespace beman
-
-#line 6 "include/beman/execution/detail/suppress_push.hpp"
-#if defined(__GNUC__)
-#define BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wmissing-braces"
-#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
-#endif
-
-#if defined(__clang__)
-#define BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunknown-warning-option"
-#pragma clang diagnostic ignored "-Wmissing-braces"
-#pragma clang diagnostic ignored "-Wc++26-extensions"
-#endif
-#line 3 "include/beman/execution/detail/suppress_pop.hpp"
-
-#line 6 "include/beman/execution/detail/suppress_pop.hpp"
-#ifdef BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
-#if defined(__GNUC__)
-#pragma GCC diagnostic pop
-#endif
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-#undef BEMAN_EXECUTION_DIAGNOSTIC_PUSHED
-#endif
-#line 3 "include/beman/execution/detail/queryable.hpp"
-
-#line 12 "include/beman/execution/detail/queryable.hpp"
-namespace beman::execution::detail {
-template <typename T>
-concept queryable = ::std::destructible<T>;
-}
-#line 14 "include/beman/execution/detail/forwarding_query.hpp"
-namespace beman::execution::detail {
-
-#line 20 "include/beman/execution/detail/forwarding_query.hpp"
-struct forwarding_query_t {
-    template <typename Object>
-        requires requires(Object&& object, const forwarding_query_t& query) {
-            { ::std::forward<Object>(object).query(query) } noexcept -> ::std::same_as<bool>;
-        }
-    constexpr auto operator()(Object&& object) const noexcept -> bool {
-        return ::std::forward<Object>(object).query(*this);
-    }
-    template <typename Object>
-    constexpr auto operator()(Object&&) const noexcept -> bool {
-        return ::std::derived_from<::std::remove_cvref_t<Object>, ::beman::execution::detail::forwarding_query_t>;
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-
-#line 40 "include/beman/execution/detail/forwarding_query.hpp"
-export /* --------- */ using forwarding_query_t = beman::execution::detail::forwarding_query_t;
-
-#line 53 "include/beman/execution/detail/forwarding_query.hpp"
-export /* --------- */ inline constexpr forwarding_query_t forwarding_query{};
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/movable_value.hpp"
-namespace beman::execution::detail {
-template <typename T>
-concept movable_value =
-    ::std::move_constructible<::std::decay_t<T>> && ::std::constructible_from<::std::decay_t<T>, T> &&
-    (!::std::is_array_v<::std::remove_reference_t<T>>);
-}
-#line 12 "include/beman/execution/detail/matching_sig.hpp"
-namespace beman::execution::detail {
-template <typename Fun>
-struct matching_sig_transform {
-    using type = Fun;
-};
-template <typename Return, typename... Args>
-struct matching_sig_transform<Return(Args...)> {
-    using type = Return(Args&&...);
-};
-
-template <typename Fun1, typename Fun2>
-inline constexpr bool matching_sig =
-    ::std::same_as<typename ::beman::execution::detail::matching_sig_transform<Fun1>::type,
-                   typename ::beman::execution::detail::matching_sig_transform<Fun2>::type>;
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/as_except_ptr.hpp"
-namespace beman::execution::detail {
-
-#line 23 "include/beman/execution/detail/as_except_ptr.hpp"
-template <typename Error>
-decltype(auto) as_except_ptr(Error&& error) {
-    if constexpr (::std::same_as<::std::exception_ptr, ::std::decay_t<Error>>) {
-        return ::std::forward<Error>(error);
-    } else if constexpr (::std::same_as<::std::error_code, ::std::decay_t<Error>>) {
-        return ::std::make_exception_ptr(::std::system_error(error));
-    } else {
-        return ::std::make_exception_ptr(::std::forward<Error>(error));
-    }
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/set_value.hpp"
-namespace beman::execution {
-
-#line 19 "include/beman/execution/detail/set_value.hpp"
-export /* --------- */ struct set_value_t {
-    template <typename Receiver, typename... Args>
-    auto operator()(Receiver&, Args&&...) const
-        -> void = BEMAN_EXECUTION_DELETE("set_value requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver, typename... Args>
-    auto operator()(const Receiver&&, Args&&...) const
-        -> void = BEMAN_EXECUTION_DELETE("set_value requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver, typename... Args>
-    auto operator()(Receiver&&, Args&&...) const -> void
-        requires(not requires(Receiver&& receiver, Args&&... args) {
-                    ::std::forward<Receiver>(receiver).set_value(::std::forward<Args>(args)...);
-                })
-    = BEMAN_EXECUTION_DELETE("set_value requires a suitable member overload on the receiver");
-    template <typename Receiver, typename... Args>
-        requires(not noexcept(::std::declval<Receiver>().set_value(::std::declval<Args>()...)))
-    auto operator()(Receiver&&, Args&&...) const
-        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_value(args...) has to be noexcept");
-
-    template <typename Receiver, typename... Args>
-    auto operator()(Receiver&& receiver, Args&&... args) const noexcept -> void {
-        ::std::forward<Receiver>(receiver).set_value(::std::forward<Args>(args)...);
-    }
-};
-
-#line 47 "include/beman/execution/detail/set_value.hpp"
-export /* --------- */ inline constexpr set_value_t set_value{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/set_error.hpp"
-namespace beman::execution {
-
-#line 19 "include/beman/execution/detail/set_error.hpp"
-export /* --------- */ struct set_error_t {
-    template <typename Receiver, typename Error>
-    auto operator()(Receiver&, Error&&) const
-        -> void = BEMAN_EXECUTION_DELETE("set_error requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver, typename Error>
-    auto operator()(const Receiver&&, Error&&) const
-        -> void = BEMAN_EXECUTION_DELETE("set_error requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver, typename Error>
-    auto operator()(Receiver&&, Error&&) const -> void
-        requires(not requires(Receiver&& receiver, Error&& error) {
-                    ::std::forward<Receiver>(receiver).set_error(::std::forward<Error>(error));
-                })
-    = BEMAN_EXECUTION_DELETE("set_error requires a suitable member overload on the receiver");
-    template <typename Receiver, typename Error>
-        requires(not noexcept(::std::declval<Receiver>().set_error(::std::declval<Error>())))
-    auto operator()(Receiver&&, Error&&) const
-        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_error(error) has to be noexcept");
-
-    // NOLINTBEGIN(misc-no-recursion)
-    template <typename Receiver, typename Error>
-    auto operator()(Receiver&& receiver, Error&& error) const noexcept -> void {
-        ::std::forward<Receiver>(receiver).set_error(::std::forward<Error>(error));
-    }
-    // NOLINTEND(misc-no-recursion)
-};
-
-#line 49 "include/beman/execution/detail/set_error.hpp"
-export /* --------- */ inline constexpr set_error_t set_error{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/set_stopped.hpp"
-namespace beman::execution {
-
-#line 19 "include/beman/execution/detail/set_stopped.hpp"
-export /* --------- */ struct set_stopped_t {
-    template <typename Receiver>
-    auto operator()(Receiver&) const
-        -> void = BEMAN_EXECUTION_DELETE("set_stopped requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver>
-    auto operator()(const Receiver&&) const
-        -> void = BEMAN_EXECUTION_DELETE("set_stopped requires the receiver to be passed as non-const rvalue");
-    template <typename Receiver>
-    auto operator()(Receiver&&) const -> void
-        requires(not requires(Receiver&& receiver) { ::std::forward<Receiver>(receiver).set_stopped(); })
-    = BEMAN_EXECUTION_DELETE("set_stopped requires a suitable member overload on the receiver");
-    template <typename Receiver>
-        requires(not noexcept(::std::declval<Receiver>().set_stopped()))
-    auto operator()(Receiver&&) const
-        -> void = BEMAN_EXECUTION_DELETE("the call to receiver.set_stopped() has to be noexcept");
-
-    template <typename Receiver>
-    auto operator()(Receiver&& receiver) const noexcept -> void {
-        ::std::forward<Receiver>(receiver).set_stopped();
-    }
-};
-
-#line 45 "include/beman/execution/detail/set_stopped.hpp"
-export /* --------- */ inline constexpr set_stopped_t set_stopped{};
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/start.hpp"
 namespace beman::execution {
-export /* --------- */ struct start_t {
-    template <typename State>
-    auto operator()(State&&) const -> void = BEMAN_EXECUTION_DELETE("start(obj) requires an lvalue argument");
-    template <typename State>
-        requires(not requires(State& state) { state.start(); })
-    auto operator()(State&) const -> void = BEMAN_EXECUTION_DELETE("state needs to have a start() member");
-    template <typename State>
-        requires(not requires(const State& state) { state.start(); })
-    auto operator()(const State&) const -> void = BEMAN_EXECUTION_DELETE("state needs to have a start() member");
-
-    template <typename State>
-        requires(not requires(State& state) {
-                    { state.start() } noexcept;
-                })
-    auto operator()(State&) const -> void = BEMAN_EXECUTION_DELETE("state start() member has to be noexcept");
-    template <typename State>
-        requires(not requires(const State& state) {
-                    { state.start() } noexcept;
-                })
-    auto operator()(const State&) const -> void = BEMAN_EXECUTION_DELETE("state start() member has to be noexcept");
+export using beman::execution::detail::pipeable::operator|;
 
-    template <typename State>
-    auto operator()(const State& state) const noexcept -> void {
-        state.start();
-    }
-    // NOLINTBEGIN(misc-no-recursion)
-    template <typename State>
-    auto operator()(State& state) const noexcept -> void {
-        state.start();
-    }
-    // NOLINTEND(misc-no-recursion)
-};
+// [stoptoken.concepts], stop token concepts
+export using ::beman::execution::stoppable_token;
+export using ::beman::execution::unstoppable_token;
 
-export /* --------- */ inline constexpr start_t start{};
-} // namespace beman::execution
-
-#line 11 "include/beman/execution/detail/non_assignable.hpp"
-namespace beman::execution::detail {
-struct non_assignable;
-}
-#line 17 "include/beman/execution/detail/non_assignable.hpp"
-struct beman::execution::detail::non_assignable {
-    non_assignable()                                         = default;
-    non_assignable(non_assignable&&)                         = default;
-    non_assignable(const non_assignable&)                    = default;
-    auto operator=(non_assignable&&) -> non_assignable&      = delete;
-    auto operator=(const non_assignable&) -> non_assignable& = delete;
-};
-
-#line 13 "include/beman/execution/detail/simple_allocator.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <typename Alloc>
-concept simple_allocator =
-    requires(::std::remove_cvref_t<Alloc> alloc, ::std::size_t n) {
-        { *alloc.allocate(n) } -> ::std::same_as<typename ::std::remove_cvref_t<Alloc>::value_type&>;
-        alloc.deallocate(alloc.allocate(n), n);
-    } && ::std::copy_constructible<::std::remove_cvref_t<Alloc>> &&
-    ::std::equality_comparable<::std::remove_cvref_t<Alloc>>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/never_stop_token.hpp"
-namespace beman::execution {
-export /* --------- */ class never_stop_token;
-}
-#line 17 "include/beman/execution/detail/never_stop_token.hpp"
-class beman::execution::never_stop_token {
-    struct private_callback_type {
-        explicit private_callback_type(never_stop_token, auto&&) noexcept {}
-    };
-
-  public:
-    template <typename>
-    using callback_type = private_callback_type;
+// [stoptoken], class stop_token
+export using ::beman::execution::stop_token;
 
-    static constexpr auto stop_requested() noexcept -> bool { return {}; }
-    static constexpr auto stop_possible() noexcept -> bool { return {}; }
-    auto                  operator==(const never_stop_token&) const -> bool = default;
-};
+// [stopsource], class stop_source
+export using ::beman::execution::stop_source;
 
-#line 12 "include/beman/execution/detail/decayed_same_as.hpp"
-namespace beman::execution::detail {
+export using ::beman::execution::nostopstate_t;
+export using ::beman::execution::nostopstate;
 
-#line 19 "include/beman/execution/detail/decayed_same_as.hpp"
-template <typename T0, typename T1>
-concept decayed_same_as = ::std::same_as<::std::remove_cvref_t<T0>, ::std::remove_cvref_t<T1>>;
-} // namespace beman::execution::detail
+// [stopcallback], class template stop_callback
+export using ::beman::execution::stop_callback;
 
-#line 12 "include/beman/execution/detail/callable.hpp"
-namespace beman::execution::detail {
+// [stoptoken.never], class never_stop_token
+export using ::beman::execution::never_stop_token;
 
-#line 19 "include/beman/execution/detail/callable.hpp"
-template <typename Fun, typename... Args>
-concept callable = requires(Fun&& fun, Args&&... args) { ::std::forward<Fun>(fun)(::std::forward<Args>(args)...); };
-} // namespace beman::execution::detail
+// [stoptoken.inplace], class inplace_stop_token
+export using ::beman::execution::inplace_stop_token;
 
-#line 15 "include/beman/execution/detail/forward_like.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct forward_like_helper;
+// [stopsource.inplace], class inplace_stop_source
+export using ::beman::execution::inplace_stop_source;
 
-template <typename T>
-struct forward_like_helper {
-    template <typename U>
-    static auto forward(U&& u) -> ::std::remove_reference_t<U>&& {
-        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
-    }
-};
-template <typename T>
-struct forward_like_helper<T&&> {
-    template <typename U>
-    static auto forward(U&& u) -> ::std::remove_cvref_t<U>&& {
-        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
-    }
-};
-template <typename T>
-struct forward_like_helper<T&> {
-    template <typename U>
-    static auto forward(U&& u) -> ::std::remove_cvref_t<U>& {
-        return ::std::forward<U&&>(u);
-    }
-};
-template <typename T>
-struct forward_like_helper<const T&&> {
-    template <typename U>
-    static auto forward(U&& u) -> const ::std::remove_cvref_t<U>&& {
-        return ::std::move(u); // NOLINT(bugprone-move-forwarding-reference)
-    }
-};
-template <typename T>
-struct forward_like_helper<const T&> {
-    template <typename U>
-    static auto forward(U&& u) -> const ::std::remove_cvref_t<U>& {
-        return ::std::forward<U&&>(u);
-    }
-};
+// [stopcallback.inplace], class template inplace_stop_callback
+export using ::beman::execution::inplace_stop_callback;
+export using ::beman::execution::stop_callback_for_t;
 
-#line 57 "include/beman/execution/detail/forward_like.hpp"
-template <typename T, typename U>
-auto own_forward_like(U&& u) noexcept -> decltype(auto) {
-    return ::beman::execution::detail::forward_like_helper<T>::forward(::std::forward<U>(u));
-}
-#line 67 "include/beman/execution/detail/forward_like.hpp"
-template <typename T, typename U>
-auto forward_like(U&& u) noexcept -> decltype(auto) {
-#if 202207 <= disabled__cpp_lib_forward_like
-    return ::std::forward_like<T>(::std::forward<U>(u));
-#else
-    return ::beman::execution::detail::forward_like_helper<T>::forward(::std::forward<U>(u));
+#if 0
+    //-dk:TODO enable the execution policies
+    export using ::std::is_execution_policy;
+    export using ::std::is_execution_policy_v;
+
+    export using ::std::execution::sequenced_policy;
+    export using ::std::execution::parallel_policy;
+    export using ::std::execution::parallel_unsequenced_policy;
+    export using ::std::execution::unsequenced_policy;
+
+    export using ::std::execution::seq;
+    export using ::std::execution::par;
+    export using ::std::execution::par_unseq;
+    export using ::std::execution::unseq;
 #endif
-}
-#line 76 "include/beman/execution/detail/forward_like.hpp"
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/join_env.hpp"
-namespace beman::execution::detail {
-template <typename Env1, typename Env2>
-class join_env {
-  private:
-    Env1 env1;
-    Env2 env2;
-
-  public:
-    template <typename E1, typename E2>
-    join_env(E1&& e1, E2&& e2) : env1(::std::forward<E1>(e1)), env2(::std::forward<E2>(e2)) {}
-
-    template <typename Query, typename... Args>
-        requires requires(Env1&, const Query& query, Args&&... args) {
-            env1.query(query, ::std::forward<Args>(args)...);
-        }
-    auto query(const Query& query, Args&&... args) noexcept -> decltype(auto) {
-        return this->env1.query(query, ::std::forward<Args>(args)...);
-    }
-    template <typename Query, typename... Args>
-        requires(
-            not requires(Env1&, const Query& query, Args&&... args) {
-                env1.query(query, ::std::forward<Args>(args)...);
-            } &&
-            requires(Env2& e2, const Query& query, Args&&... args) { e2.query(query, ::std::forward<Args>(args)...); })
-    auto query(const Query& query, Args&&... args) noexcept -> decltype(auto) {
-        return this->env2.query(query, ::std::forward<Args>(args)...);
-    }
-    template <typename Query, typename... Args>
-        requires requires(const Env1& e1, const Query& query, Args&&... args) {
-            { e1.query(query, ::std::forward<Args>(args)...) } noexcept;
-        }
-    auto query(const Query& query, Args&&... args) const noexcept -> decltype(auto) {
-        return this->env1.query(query, ::std::forward<Args>(args)...);
-    }
-    template <typename Query, typename... Args>
-        requires(
-            not requires(const Env1& e1, const Query& query, Args&&... args) {
-                { e1.query(query, ::std::forward<Args>(args)...) } noexcept;
-            } &&
-            requires(const Env2& e2, const Query& query, Args&&... args) {
-                { e2.query(query, ::std::forward<Args>(args)...) } noexcept;
-            })
-    auto query(const Query& query, Args&&... args) const noexcept -> decltype(auto) {
-        return this->env2.query(query, ::std::forward<Args>(args)...);
-    }
-};
-
-template <typename Env1, typename Env2>
-join_env(Env1&&, Env2&&) -> join_env<::std::remove_cvref_t<Env1>, ::std::remove_cvref_t<Env2>>;
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/product_type.hpp"
-namespace beman::execution::detail {
-
-template <::std::size_t I, typename T>
-struct product_type_element {
-    T    value;
-    auto operator==(const product_type_element&) const -> bool = default;
-};
-
-template <typename, typename...>
-struct product_type_base;
-
-template <::std::size_t... I, typename... T>
-struct product_type_base<::std::index_sequence<I...>, T...>
-    : ::beman::execution::detail::product_type_element<I, T>... {
-    static constexpr ::std::size_t size() { return sizeof...(T); }
-    static constexpr bool          is_product_type{true};
-
-    template <::std::size_t J, typename S>
-    static auto element_get(::beman::execution::detail::product_type_element<J, S>& self) noexcept -> S& {
-        return self.value;
-    }
-    template <::std::size_t J, typename S>
-    static auto element_get(::beman::execution::detail::product_type_element<J, S>&& self) noexcept -> S&& {
-        return ::std::move(self.value);
-    }
-    template <::std::size_t J, typename S>
-    static auto element_get(const ::beman::execution::detail::product_type_element<J, S>& self) noexcept -> const S& {
-        return self.value;
-    }
-#line 45 "include/beman/execution/detail/product_type.hpp"
-    template <::std::size_t J>
-    auto get() & -> decltype(auto) {
-        return this->element_get<J>(*this);
-    }
-    template <::std::size_t J>
-    auto get() && -> decltype(auto) {
-        return this->element_get<J>(::std::move(*this));
-    }
-    template <::std::size_t J>
-    auto get() const& -> decltype(auto) {
-        return this->element_get<J>(*this);
-    }
-#line 58 "include/beman/execution/detail/product_type.hpp"
-    template <::std::size_t J, typename Allocator, typename Self>
-    static auto make_element(Allocator&& alloc, Self&& self) -> decltype(auto) {
-        using type = ::std::remove_cvref_t<decltype(product_type_base::element_get<J>(std::forward<Self>(self)))>;
-        if constexpr (::std::uses_allocator_v<type, Allocator>)
-            return ::std::make_obj_using_allocator<type>(alloc,
-                                                         product_type_base::element_get<J>(std::forward<Self>(self)));
-        else
-            return product_type_base::element_get<J>(std::forward<Self>(self));
-    }
-#line 68 "include/beman/execution/detail/product_type.hpp"
-    auto operator==(const product_type_base&) const -> bool = default;
-};
 
-template <typename T>
-concept is_product_type_c = requires(const T& t) { T::is_product_type; };
+// [exec.queries], queries
+export using ::beman::execution::forwarding_query_t;
+export using ::beman::execution::get_allocator_t;
+export using ::beman::execution::get_stop_token_t;
+
+export using ::beman::execution::forwarding_query;
+export using ::beman::execution::get_allocator;
+export using ::beman::execution::get_stop_token;
+
+export using ::beman::execution::stop_token_of_t;
+
+export using ::beman::execution::get_domain_t;
+export using ::beman::execution::get_scheduler_t;
+export using ::beman::execution::get_delegation_scheduler_t;
+//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee_t;
+export using ::beman::execution::get_completion_scheduler_t;
+
+export using ::beman::execution::get_domain;
+export using ::beman::execution::get_scheduler;
+export using ::beman::execution::get_delegation_scheduler;
+//-dk:TODO export using ::beman::execution::forward_progress_guarantee;
+//-dk:TODO export using ::beman::execution::get_forward_progress_guarantee;
+export using ::beman::execution::get_completion_scheduler;
+
+export using ::beman::execution::env;
+export using ::beman::execution::get_env_t;
+export using ::beman::execution::get_env;
+
+export using ::beman::execution::env_of_t;
+
+// [exec.domain.default], execution_domains
+export using ::beman::execution::default_domain;
+
+// [exec.sched], schedulers
+export using ::beman::execution::scheduler_t;
+export using ::beman::execution::scheduler;
+
+// [exec.recv], receivers
+export using ::beman::execution::receiver_t;
+export using ::beman::execution::receiver;
+export using ::beman::execution::receiver_of;
+
+export using ::beman::execution::set_value_t;
+export using ::beman::execution::set_error_t;
+export using ::beman::execution::set_stopped_t;
+
+export using ::beman::execution::set_value;
+export using ::beman::execution::set_error;
+export using ::beman::execution::set_stopped;
+
+// [exec.opstate], operation states
+export using ::beman::execution::operation_state_t;
+export using ::beman::execution::operation_state;
+export using ::beman::execution::start_t;
+export using ::beman::execution::start;
+
+// [exec.snd], senders
+export using ::beman::execution::sender_t;
+export using ::beman::execution::sender;
+export using ::beman::execution::sender_in;
+//-dk:TODO export using ::beman::execution::sender_to;
+
+// [exec.getcomplsigs], completion signatures
+export using ::beman::execution::get_completion_signatures_t;
+export using ::beman::execution::get_completion_signatures;
+export using ::beman::execution::completion_signatures_of_t;
+export using ::beman::execution::value_types_of_t;
+export using ::beman::execution::error_types_of_t;
+export using ::beman::execution::sends_stopped;
+export using ::beman::execution::tag_of_t;
+
+// [exec.snd.transform], sender transformations
+export using ::beman::execution::transform_sender;
+
+// [exec.snd.transform.env], environment transformations
+//-dk:TODO export using ::beman::execution::transform_env;
+
+// [exec.snd.apply], sender algorithm application
+export using ::beman::execution::apply_sender;
+
+// [exec.connect], the connect sender algorithm
+export using ::beman::execution::connect_t;
+export using ::beman::execution::connect;
+export using ::beman::execution::connect_result_t;
+
+// [exec.factories], sender factories
+export using ::beman::execution::just_t;
+export using ::beman::execution::just_error_t;
+export using ::beman::execution::just_stopped_t;
+export using ::beman::execution::schedule_t;
+
+export using ::beman::execution::just;
+export using ::beman::execution::just_error;
+export using ::beman::execution::just_stopped;
+export using ::beman::execution::schedule;
+export using ::beman::execution::read_env;
+
+export using ::beman::execution::schedule_result_t;
+
+// [exec.adapt], sender adaptors
+export using ::beman::execution::sender_adaptor_closure;
+
+export using ::beman::execution::starts_on_t;
+export using ::beman::execution::continues_on_t;
+export using ::beman::execution::on_t;
+export using ::beman::execution::schedule_from_t;
+export using ::beman::execution::then_t;
+export using ::beman::execution::upon_error_t;
+export using ::beman::execution::upon_stopped_t;
+export using ::beman::execution::let_value_t;
+export using ::beman::execution::let_error_t;
+export using ::beman::execution::let_stopped_t;
+export using ::beman::execution::bulk_t;
+export using ::beman::execution::split_t;
+export using ::beman::execution::when_all_t;
+export using ::beman::execution::when_all_with_variant_t;
+export using ::beman::execution::into_variant_t;
+//-dk:TODO export using ::beman::execution::stopped_as_optional_t;
+//-dk:TODO export using ::beman::execution::stopped_as_error_t;
+
+export using ::beman::execution::starts_on;
+export using ::beman::execution::continues_on;
+export using ::beman::execution::on;
+export using ::beman::execution::schedule_from;
+export using ::beman::execution::then;
+export using ::beman::execution::upon_error;
+export using ::beman::execution::upon_stopped;
+export using ::beman::execution::let_value;
+export using ::beman::execution::let_error;
+export using ::beman::execution::let_stopped;
+export using ::beman::execution::bulk;
+export using ::beman::execution::split;
+export using ::beman::execution::when_all;
+export using ::beman::execution::when_all_with_variant;
+export using ::beman::execution::into_variant;
+//-dk:TODO export using ::beman::execution::stopped_as_optional;
+//-dk:TODO export using ::beman::execution::stopped_as_error;
+
+// [exec.util.cmplsig]
+export using ::beman::execution::completion_signatures;
+
+// [exec.util.cmplsig.trans]
+//-dk:TODO export using ::beman::execution::transform_completion_signatures;
+//-dk:TODO export using ::beman::execution::transform_completion_signatures_of;
+
+// [exec.run.loop], run_loop
+export using ::beman::execution::run_loop;
+
+// [exec.consumers], consumers
+export using ::beman::execution::sync_wait_t;
+//-dk:TODO export using ::beman::execution::sync_wait_with_variant_t;
+
+export using ::beman::execution::sync_wait;
+//-dk:TODO export using ::beman::execution::sync_wait_with_variant;
+
+// [exec.as.awaitable]
+export using ::beman::execution::as_awaitable_t;
+export using ::beman::execution::as_awaitable;
+
+// [exec.with.awaitable.senders]
+export using ::beman::execution::with_awaitable_senders;
+
+//-dk:TODO add section
+export using ::beman::execution::prop;
+export using ::beman::execution::write_env_t;
+export using ::beman::execution::write_env;
+export using ::beman::execution::affine_on_t;
+export using ::beman::execution::affine_on;
+export using ::beman::execution::read_env_t;
+export using ::beman::execution::read_env;
+export using ::beman::execution::simple_counting_scope;
+export using ::beman::execution::counting_scope;
+export using ::beman::execution::scope_token;
+
+namespace detail {
+export using ::beman::execution::detail::basic_sender;
+export using ::beman::execution::detail::product_type;
+export using ::beman::execution::detail::product_type_base;
+export using ::beman::execution::detail::is_product_type_c;
+export using ::beman::execution::detail::env_promise;
+export using ::beman::execution::detail::await_result_type;
+export using ::beman::execution::detail::simple_allocator;
+export using ::beman::execution::detail::sync_wait_env;
+export using ::beman::execution::detail::sync_wait_result_type;
+export using ::beman::execution::detail::sync_wait_state;
+export using ::beman::execution::detail::sync_wait_receiver;
+export using ::beman::execution::detail::connect_all_t;
+export using ::beman::execution::detail::connect_all;
+} // namespace detail
 
-template <typename... T>
-struct product_type : ::beman::execution::detail::product_type_base<::std::index_sequence_for<T...>, T...> {
-    template <typename Allocator, typename Product, std::size_t... I>
-    static auto make_from(Allocator&& allocator, Product&& product, std::index_sequence<I...>) -> product_type {
-        return {product_type::template make_element<I>(allocator, ::std::forward<Product>(product))...};
-    }
-#line 81 "include/beman/execution/detail/product_type.hpp"
-    template <typename Allocator, typename Product>
-    static auto make_from(Allocator&& allocator, Product&& product) -> product_type {
-        return product_type::make_from(
-            ::std::forward<Allocator>(allocator), ::std::forward<Product>(product), ::std::index_sequence_for<T...>{});
-    }
-#line 87 "include/beman/execution/detail/product_type.hpp"
-    template <typename Fun, ::std::size_t... I>
-    constexpr auto apply_elements(::std::index_sequence<I...>, Fun&& fun) const -> decltype(auto) {
-        return ::std::forward<Fun>(fun)(this->template get<I>()...);
-    }
-    template <typename Fun>
-    constexpr auto apply(Fun&& fun) const -> decltype(auto) {
-        return apply_elements(::std::index_sequence_for<T...>{}, ::std::forward<Fun>(fun));
-    }
-    template <typename Fun, ::std::size_t... I>
-    constexpr auto apply_elements(::std::index_sequence<I...>, Fun&& fun) -> decltype(auto) {
-
-        return ::std::forward<Fun>(fun)(std::move(this->template get<I>())...);
-    }
-    template <typename Fun>
-    constexpr auto apply(Fun&& fun) -> decltype(auto) {
-        return apply_elements(::std::index_sequence_for<T...>{}, ::std::forward<Fun>(fun));
-    }
-};
-template <typename... T>
-product_type(T&&...) -> product_type<::std::decay_t<T>...>;
-
-template <typename T>
-constexpr auto is_product_type(const T&) -> ::std::false_type {
-    return {};
-}
-template <typename... T>
-constexpr auto is_product_type(const ::beman::execution::detail::product_type<T...>&) -> ::std::true_type {
-    return {};
-}
-#line 117 "include/beman/execution/detail/product_type.hpp"
-template <::std::size_t Start, typename Fun, typename Tuple, ::std::size_t... I>
-constexpr auto sub_apply_helper(Fun&& fun, Tuple&& tuple, ::std::index_sequence<I...>) -> decltype(auto) {
-    // NOLINTNEXTLINE(bugprone-use-after-move,hicpp-invalid-access-moved)
-    return ::std::forward<Fun>(fun)(::std::forward<Tuple>(tuple).template get<I + Start>()...);
-}
-#line 123 "include/beman/execution/detail/product_type.hpp"
-template <::std::size_t Start, typename Fun, typename Tuple>
-constexpr auto sub_apply(Fun&& fun, Tuple&& tuple) -> decltype(auto) {
-    constexpr ::std::size_t TSize{::std::tuple_size_v<::std::remove_cvref_t<Tuple>>};
-    static_assert(Start <= TSize);
-    return sub_apply_helper<Start>(
-        ::std::forward<Fun>(fun), ::std::forward<Tuple>(tuple), ::std::make_index_sequence<TSize - Start>());
-}
-#line 131 "include/beman/execution/detail/product_type.hpp"
-} // namespace beman::execution::detail
+} // namespace beman::execution
 
 namespace std {
-template <typename T>
+export template <typename T>
     requires ::beman::execution::detail::is_product_type_c<T>
-struct tuple_size<T> : ::std::integral_constant<std::size_t, T::size()> {};
+struct tuple_size<T>;
 
-template <::std::size_t I, typename T>
+export template <::std::size_t I, typename T>
     requires ::beman::execution::detail::is_product_type_c<T>
-struct tuple_element<I, T> {
-    using type = ::std::decay_t<decltype(::std::declval<T>().template get<I>())>;
-};
+struct tuple_element<I, T>;
 } // namespace std
-
-#line 12 "include/beman/execution/detail/query_with_default.hpp"
-namespace beman::execution::detail {
-template <typename Tag, typename Env, typename Value>
-    requires requires(const Tag& tag, const Env& env) { tag(env); }
-constexpr auto query_with_default(Tag, const Env& env, Value&&) noexcept(noexcept(Tag()(env))) -> decltype(auto) {
-    return Tag()(env);
-}
-#line 19 "include/beman/execution/detail/query_with_default.hpp"
-template <typename Tag, typename Env, typename Value>
-constexpr auto
-query_with_default(Tag, const Env&, Value&& value) noexcept(noexcept(static_cast<Value>(std::forward<Value>(value))))
-    -> decltype(auto) {
-    return static_cast<Value>(std::forward<Value>(value));
-}
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/child_type.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/child_type.hpp"
-template <typename Sender, ::std::size_t I = 0u>
-using child_type = decltype(::std::declval<Sender>().template get<I + 2>());
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/decayed_tuple.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/decayed_tuple.hpp"
-template <typename... T>
-using decayed_tuple = ::std::tuple<::std::decay_t<T>...>;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/make_env.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <typename Query, typename Value>
-class make_env {
-  private:
-    Value value;
-
-  public:
-    template <typename V>
-    make_env(const Query&, V&& v) : value(::std::forward<V>(v)) {}
-    constexpr auto query(const Query&) const noexcept -> const Value& { return this->value; }
-    constexpr auto query(const Query&) noexcept -> Value& { return this->value; }
-};
-template <typename Query, typename Value>
-make_env(Query&&, Value&& value) -> make_env<::std::remove_cvref_t<Query>, ::std::remove_cvref_t<Value>>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/meta_prepend.hpp"
-namespace beman::execution::detail::meta::detail {
-template <typename, typename>
-struct prepend;
-
-template <template <typename...> class List, typename H, typename... T>
-struct prepend<H, List<T...>> {
-    using type = List<H, T...>;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <typename H, typename Tail>
-using prepend = typename ::beman::execution::detail::meta::detail::prepend<H, Tail>::type;
-}
-#line 11 "include/beman/execution/detail/meta_to.hpp"
-namespace beman::execution::detail::meta {
-template <template <typename...> class To, typename>
-struct to_type_list;
-template <template <typename...> class To, template <typename...> class List, typename... T>
-struct to_type_list<To, List<T...>> {
-    using type = To<T...>;
-};
-template <template <typename...> class To, typename T>
-using to = typename ::beman::execution::detail::meta::to_type_list<To, T>::type;
-} // namespace beman::execution::detail::meta
-
-#line 11 "include/beman/execution/detail/type_list.hpp"
-namespace beman::execution::detail {
-template <typename...>
-struct type_list {};
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/stop_callback_for_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <class Token, class CallbackFun>
-using stop_callback_for_t = typename Token::template callback_type<CallbackFun>;
-}
-#line 17 "include/beman/execution/detail/stop_callback_for_t.hpp"
-namespace beman::execution::detail {
-template <typename CallbackFun, typename Token, typename Initializer = CallbackFun>
-concept stoppable_callback_for =
-    ::std::invocable<CallbackFun> && ::std::constructible_from<CallbackFun, Initializer> &&
-    requires { typename ::beman::execution::stop_callback_for_t<Token, CallbackFun>; } &&
-    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, Token, Initializer> &&
-    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, Token&, Initializer> &&
-    ::std::constructible_from<::beman::execution::stop_callback_for_t<Token, CallbackFun>, const Token&, Initializer>;
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/call_result_t.hpp"
-namespace beman::execution::detail {
-template <typename Fun, typename... Args>
-
-#line 19 "include/beman/execution/detail/call_result_t.hpp"
-using call_result_t = decltype(::std::declval<Fun>()(std::declval<Args>()...));
-} // namespace beman::execution::detail
-#line 12 "include/beman/execution/detail/meta_size.hpp"
-namespace beman::execution::detail::meta {
-template <typename>
-struct size;
-template <template <typename...> class L, typename... T>
-struct size<L<T...>> {
-    static constexpr ::std::size_t value{sizeof...(T)};
-};
-template <typename T>
-inline constexpr ::std::size_t size_v{::beman::execution::detail::meta::size<T>::value};
-} // namespace beman::execution::detail::meta
-
-#line 11 "include/beman/execution/detail/on_stop_request.hpp"
-namespace beman::execution::detail {
-template <typename St>
-struct on_stop_request {
-    St&  st;
-    auto operator()() const -> void { this->st.request_stop(); }
-};
-template <typename T>
-on_stop_request(T&) -> on_stop_request<T>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/check_type_alias_exist.hpp"
-namespace beman::execution::detail {
-
-#line 17 "include/beman/execution/detail/check_type_alias_exist.hpp"
-template <template <typename> class>
-struct check_type_alias_exist;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/scheduler_t.hpp"
-namespace beman::execution {
-
-#line 16 "include/beman/execution/detail/scheduler_t.hpp"
-export /* --------- */ struct scheduler_t {};
-} // namespace beman::execution
-
-#line 12 "include/beman/execution/detail/get_awaiter.hpp"
-namespace beman::execution::detail {
-template <typename Expr, typename Promise>
-auto get_awaiter(Expr&& expr, Promise& promise) -> decltype(auto) {
-    auto transform{[&]() -> decltype(auto) {
-        if constexpr (requires { promise.await_transform(::std::forward<Expr>(expr)); })
-            return promise.await_transform(::std::forward<Expr>(expr));
-        else
-            return ::std::forward<Expr>(expr);
-    }};
-    if constexpr (requires { operator co_await(transform()); }) {
-
-        static_assert(not requires { transform().operator co_await(); }, "only one operator co_await is allowed");
-        return operator co_await(transform());
-    } else if constexpr (requires { transform().operator co_await(); })
-        return transform().operator co_await();
-    else
-        return transform();
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/sender_decompose.hpp"
-namespace beman::execution::detail {
-struct sender_convert_to_any_t {
-    template <typename T>
-    constexpr operator T() const; // NOLINT(hicpp-explicit-conversions)
-};
-
-template <typename Tag, typename Data, typename Children>
-struct sender_meta {
-    using tag_type      = ::std::remove_cvref_t<Tag>;
-    using data_type     = ::std::remove_cvref_t<Data>;
-    using children_type = ::std::remove_cvref_t<Children>;
-};
-
-template <typename Tag, typename Data, typename Children>
-struct sender_data {
-    using tag_type      = ::std::remove_cvref_t<Tag>;
-    using data_type     = ::std::remove_cvref_t<Data>;
-    using children_type = ::std::remove_cvref_t<Children>;
-
-    tag_type tag;
-    Data&    data;
-    Children children;
-};
-template <typename Tag, typename Data, typename Children>
-sender_data(Tag&&, Data&, Children&&) -> sender_data<Tag, Data, Children>;
-
-template <typename Sender>
-auto get_sender_data(Sender&& sender) {
-#if 0
-
-        auto&& [tag, data, ... children] = sender;
-        return sender_meta<decltype(tag), decltype(data), ::std::tuple<decltype(children)...>>;
-#else
-    using sender_type = ::std::remove_cvref_t<Sender>;
-    static constexpr ::beman::execution::detail::sender_convert_to_any_t at{};
-
-    if constexpr (requires {
-                      sender.template get<0>();
-                      sender.size();
-                  })
-        return [&sender]<::std::size_t... I>(::std::index_sequence<I...>) {
-            return ::beman::execution::detail::sender_data{
-                sender.template get<0>(), sender.template get<1>(), ::std::tie(sender.template get<2 + I>()...)};
-        }(::std::make_index_sequence<::std::decay_t<decltype(sender)>::size() - 2u>{});
-    else if constexpr (requires { sender_type{at, at, at, at, at, at}; }) {
-        auto&& [tag, data, c0, c1, c2, c3] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1, c2, c3)};
-    } else if constexpr (requires { sender_type{at, at, at, at, at}; }) {
-        auto&& [tag, data, c0, c1, c2] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1, c2)};
-    } else if constexpr (requires { sender_type{at, at, at, at}; }) {
-        auto&& [tag, data, c0, c1] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0, c1)};
-    } else if constexpr (requires { sender_type{at, at, at}; }) {
-        auto&& [tag, data, c0] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tie(c0)};
-    } else if constexpr (requires { sender_type{at, at}; }) {
-        auto&& [tag, data] = sender;
-        return ::beman::execution::detail::sender_data{tag, data, ::std::tuple<>{}};
-    } else {
-        return ::beman::execution::detail::sender_meta<void, void, void>{};
-    }
-#endif
-}
-#line 79 "include/beman/execution/detail/sender_decompose.hpp"
-template <typename Sender>
-auto get_sender_meta(Sender&& sender) {
-    using type = decltype(get_sender_data(sender));
-    return sender_meta<typename type::tag_type, typename type::data_type, typename type::children_type>{};
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/suspend_complete.hpp"
-namespace beman::execution::detail {
-template <typename Fun, typename... Args>
-auto suspend_complete(Fun fun, Args&&... args) noexcept {
-    auto f{[&, fun]() noexcept { fun(::std::forward<Args>(args)...); }};
-    struct awaiter {
-        decltype(f) fun;
-
-        static constexpr auto await_ready() noexcept -> bool { return false; }
-        auto                  await_suspend(::std::coroutine_handle<>) noexcept { this->fun(); }
-#if __cpp_lib_unreachable < 202202L
-        [[noreturn]] auto await_resume() noexcept -> void { ::std::terminate(); }
-#else
-        [[noreturn]] auto await_resume() noexcept -> void { ::std::unreachable(); }
-#endif
-    };
-    return awaiter{f};
-}
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/meta_contains.hpp"
-namespace beman::execution::detail::meta {
-template <typename T, typename... S>
-inline constexpr bool contains{(::std::same_as<T, S> || ...)};
-}
-#line 13 "include/beman/execution/detail/decays_to.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/decays_to.hpp"
-template <typename From, typename To>
-concept decays_to = ::std::same_as<::std::decay_t<From>, To>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/intrusive_stack.hpp"
-namespace beman::execution::detail {
-
-template <auto Next>
-class atomic_intrusive_stack;
-
-template <auto Next>
-class intrusive_stack;
-
-#line 20 "include/beman/execution/detail/intrusive_stack.hpp"
-template <class Item, Item* Item::* Next>
-class intrusive_stack<Next> {
-  public:
-#line 24 "include/beman/execution/detail/intrusive_stack.hpp"
-    auto push(Item* item) noexcept -> void { item->*Next = std::exchange(head_, item); }
-
-#line 29 "include/beman/execution/detail/intrusive_stack.hpp"
-    auto pop() noexcept -> Item* {
-        if (head_) {
-            auto item = head_;
-            head_     = std::exchange(item->*Next, nullptr);
-            return item;
-        }
-        return nullptr;
-    }
-#line 39 "include/beman/execution/detail/intrusive_stack.hpp"
-    auto empty() const noexcept -> bool { return !head_; }
-
-  private:
-    friend class atomic_intrusive_stack<Next>;
-    Item* head_{nullptr};
-};
-
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/immovable.hpp"
-namespace beman::execution::detail {
-struct immovable;
-struct virtual_immovable;
-} // namespace beman::execution::detail
-
-struct beman::execution::detail::immovable {
-    constexpr immovable()                          = default;
-    immovable(immovable&&)                         = delete;
-    immovable(const immovable&)                    = delete;
-    ~immovable()                                   = default;
-    auto operator=(immovable&&) -> immovable&      = delete;
-    auto operator=(const immovable&) -> immovable& = delete;
-};
-
-struct beman::execution::detail::virtual_immovable {
-    constexpr virtual_immovable()                                  = default;
-    virtual_immovable(virtual_immovable&&)                         = delete;
-    virtual_immovable(const virtual_immovable&)                    = delete;
-    virtual ~virtual_immovable()                                   = default;
-    auto operator=(virtual_immovable&&) -> virtual_immovable&      = delete;
-    auto operator=(const virtual_immovable&) -> virtual_immovable& = delete;
-};
-
-#line 10 "include/beman/execution/detail/unspecified_promise.hpp"
-namespace beman::execution::detail {
-struct unspecified_promise {
-    auto get_return_object() noexcept -> unspecified_promise;
-    auto initial_suspend() noexcept -> ::std::suspend_never;
-    auto final_suspend() noexcept -> ::std::suspend_never;
-    void unhandled_exception() noexcept;
-    void return_void() noexcept;
-    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<>;
-};
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/await_suspend_result.hpp"
-namespace beman::execution::detail {
-
-#line 20 "include/beman/execution/detail/await_suspend_result.hpp"
-template <typename>
-struct is_coroutine_handle : ::std::false_type {};
-
-#line 27 "include/beman/execution/detail/await_suspend_result.hpp"
-template <typename T>
-struct is_coroutine_handle<::std::coroutine_handle<T>> : ::std::true_type {};
-
-#line 35 "include/beman/execution/detail/await_suspend_result.hpp"
-template <typename T>
-concept await_suspend_result =
-    ::std::same_as<T, void> || ::std::same_as<T, bool> || ::beman::execution::detail::is_coroutine_handle<T>::value;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/valid_specialization.hpp"
-namespace beman::execution::detail {
-template <template <typename...> class T, typename... Args>
-concept valid_specialization = requires { typename T<Args...>; };
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/indirect_meta_apply.hpp"
-namespace beman::execution::detail {
-template <bool>
-struct indirect_meta_apply {
-    template <template <typename...> class T, class... A>
-    using meta_apply = T<A...>;
-};
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/indices_for.hpp"
-namespace beman::execution::detail {
-
-export /* --------- */ template <typename Sender>
-using indices_for = typename ::std::remove_reference_t<Sender>::indices_for;
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/decayed_typeof.hpp"
-namespace beman::execution::detail {
-
-#line 18 "include/beman/execution/detail/decayed_typeof.hpp"
-template <auto&& Tag>
-using decayed_typeof = ::std::decay_t<decltype(Tag)>;
-} // namespace beman::execution::detail
-
-#line 11 "include/beman/execution/detail/nostopstate.hpp"
-namespace beman::execution {
-export /* --------- */ struct nostopstate_t {
-    explicit nostopstate_t() = default;
-};
-
-export /* --------- */ inline constexpr nostopstate_t nostopstate{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/env.hpp"
-namespace beman::execution::detail {
-template <::beman::execution::detail::queryable Env>
-struct env_base {
-    Env env_;
-};
-
-template <typename E, typename Q>
-concept has_query = requires(const E& e) { e.query(::std::declval<Q>()); };
-
-template <typename Q, typename... E>
-struct find_env;
-template <typename Q, typename E0, typename... E>
-    requires has_query<E0, Q>
-struct find_env<Q, E0, E...> {
-    using type = E0;
-};
-template <typename Q, typename E0, typename... E>
-    requires(not has_query<E0, Q>)
-struct find_env<Q, E0, E...> {
-    using type = typename find_env<Q, E...>::type;
-};
-} // namespace beman::execution::detail
-
-#line 39 "include/beman/execution/detail/env.hpp"
-namespace beman::execution {
-export /* --------- */ template <::beman::execution::detail::queryable... Envs>
-struct env : ::beman::execution::detail::env_base<Envs>... {
-    [[no_unique_address]] ::beman::execution::detail::non_assignable na_{};
-
-    template <typename Q>
-        requires(::beman::execution::detail::has_query<Envs, Q> || ...)
-    constexpr auto query(Q q) const noexcept -> decltype(auto) {
-        using E = typename ::beman::execution::detail::find_env<Q, Envs...>::type;
-        return q(static_cast<const ::beman::execution::detail::env_base<E>&>(*this).env_);
-    }
-};
-
-template <::beman::execution::detail::queryable... Envs>
-env(Envs...) -> env<::std::unwrap_reference_t<Envs>...>;
-} // namespace beman::execution
-
-#line 17 "include/beman/execution/detail/get_allocator.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_allocator_t {
-    template <typename Object>
-        requires(not requires(Object&& object, const get_allocator_t& tag) { ::std::as_const(object).query(tag); })
-    auto
-    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the object requires a const query(get_allocator_t) overload");
-    template <typename Object>
-        requires(
-                    not requires(const Object& object, const get_allocator_t& tag) { object.query(tag); } &&
-                    not requires(Object&& object, const get_allocator_t& tag) { ::std::as_const(object).query(tag); })
-    auto operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the object requires a query(get_allocator_t) overload");
-    template <typename Object>
-        requires(not requires(const Object& object, const get_allocator_t& tag) {
-                    { object.query(tag) } noexcept;
-                })
-    auto
-    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the query(get_allocator_t) overload needs to be noexcept");
-
-    template <typename Object>
-        requires(not requires(const Object& object, const get_allocator_t& tag) {
-                    { object.query(tag) } noexcept -> ::beman::execution::detail::simple_allocator<>;
-                })
-    auto
-    operator()(Object&&) const = BEMAN_EXECUTION_DELETE("the query(get_allocator_t) overload needs to be noexcept");
-
-    template <typename Object>
-        requires(requires(const Object& object, const get_allocator_t& tag) {
-            { object.query(tag) } noexcept -> ::beman::execution::detail::simple_allocator<>;
-        })
-    auto operator()(Object&& object) const noexcept {
-        return ::std::as_const(object).query(*this);
-    }
-#line 50 "include/beman/execution/detail/get_allocator.hpp"
-    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
-};
-
-export /* --------- */ inline constexpr get_allocator_t get_allocator{};
-} // namespace beman::execution
-
-#line 15 "include/beman/execution/detail/get_domain.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_domain_t {
-    template <typename Object>
-        requires(not requires(Object&& object, const get_domain_t& tag) {
-                    ::std::forward<Object>(object).query(tag);
-                }) && (not requires(Object&& object, const get_domain_t& tag) { ::std::as_const(object).query(tag); })
-    auto operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("object needs a query(get_domain_t) overload");
-    template <typename Object>
-        requires(not requires(Object&& object, const get_domain_t& tag) { ::std::as_const(object).query(tag); })
-    auto
-    operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("query(get_domain_t) overload needs to be const");
-    template <typename Object>
-        requires(not requires(Object&& object, const get_domain_t& tag) {
-                    { ::std::as_const(object).query(tag) } noexcept;
-                })
-    auto
-    operator()(Object&&) const noexcept = BEMAN_EXECUTION_DELETE("query(get_domain_t) overload needs to be noexcept");
-
-    template <typename Object>
-    constexpr auto operator()(Object&& object) const noexcept {
-        return ::std::as_const(object).query(*this);
-    }
-    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
-};
-
-export /* --------- */ inline constexpr get_domain_t get_domain{};
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/get_scheduler.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_scheduler_t : ::beman::execution::forwarding_query_t {
-    template <typename Env>
-        requires requires(const get_scheduler_t& self, Env&& env) { ::std::as_const(env).query(self); }
-    auto operator()(Env&& env) const noexcept {
-        static_assert(noexcept(::std::as_const(env).query(*this)));
-
-#line 23 "include/beman/execution/detail/get_scheduler.hpp"
-        return ::std::as_const(env).query(*this);
-    }
-};
-
-export /* --------- */ inline constexpr get_scheduler_t get_scheduler{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/operation_state.hpp"
-namespace beman::execution {
-export /* --------- */ struct operation_state_t {};
-
-export /* --------- */ template <typename State>
-concept operation_state =
-    ::std::derived_from<typename State::operation_state_concept, ::beman::execution::operation_state_t> &&
-    ::std::is_object_v<State> && requires(State& state) {
-        { ::beman::execution::start(state) } noexcept;
-    };
-} // namespace beman::execution
-
-#line 16 "include/beman/execution/detail/valid_completion_for.hpp"
-namespace beman::execution::detail {
-template <typename, typename>
-struct valid_completion_for_aux;
-
-template <typename Rcvr, typename Tag, typename... Args>
-struct valid_completion_for_aux<Rcvr, Tag (*)(Args...)> {
-    static auto test(Tag (*)(Args...)) -> void
-        requires ::beman::execution::detail::callable<Tag, ::std::remove_cvref_t<Rcvr>, Args...>
-    {}
-};
-
-export /* --------- */ template <typename Signature, typename Rcvr>
-concept valid_completion_for = requires(Signature* signature) {
-#if 1
-    valid_completion_for_aux<Rcvr, Signature*>::test(signature);
-#else
-#line 33 "include/beman/execution/detail/valid_completion_for.hpp"
-    []<typename Tag, typename... Args>(Tag (*)(Args...))
-        requires ::beman::execution::detail::callable<Tag, ::std::remove_cvref_t<Rcvr>, Args...>
-    {}(signature);
-#endif
-};
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/completion_signature.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct is_set_error : ::std::false_type {};
-template <typename Error>
-struct is_set_error<::beman::execution::set_error_t(Error)> : ::std::true_type {};
-
-template <typename Fun>
-using is_set_stopped = ::std::is_same<Fun, ::beman::execution::set_stopped_t()>;
-
-template <typename>
-struct is_set_value : ::std::false_type {};
-template <typename... Args>
-struct is_set_value<::beman::execution::set_value_t(Args...)> : ::std::true_type {};
-
-#line 42 "include/beman/execution/detail/completion_signature.hpp"
-template <typename Fun>
-concept completion_signature =
-    ::beman::execution::detail::is_set_error<Fun>::value || ::beman::execution::detail::is_set_stopped<Fun>::value ||
-    ::beman::execution::detail::is_set_value<Fun>::value;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/prop.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct prop_like;
-}
-#line 19 "include/beman/execution/detail/prop.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Query, typename Value>
-struct prop;
-
-template <typename Query, typename Value>
-prop(Query, Value, ::beman::execution::detail::non_assignable = {}) -> prop<Query, ::std::unwrap_reference_t<Value>>;
-} // namespace beman::execution
-
-template <typename V>
-struct beman::execution::detail::prop_like {
-    V    value;
-    auto query(auto) const noexcept -> const V& { return this->value; }
-};
-
-template <typename Query, typename Value>
-struct beman::execution::prop {
-    static_assert(::beman::execution::detail::callable<Query, ::beman::execution::detail::prop_like<Value>>);
-
-    [[no_unique_address]] Query                                      query_{};
-    [[no_unique_address]] Value                                      value_{};
-    [[no_unique_address]] ::beman::execution::detail::non_assignable non_assignable_{};
-
-#line 46 "include/beman/execution/detail/prop.hpp"
-    constexpr auto query(Query) const noexcept -> const Value& { return this->value_; }
-};
-
-#line 13 "include/beman/execution/detail/stoppable_token.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Token>
-concept stoppable_token = requires(const Token& token) {
-    typename ::beman::execution::detail::check_type_alias_exist<Token::template callback_type>;
-    { token.stop_requested() } noexcept -> ::std::same_as<bool>;
-    { token.stop_possible() } noexcept -> ::std::same_as<bool>;
-    { Token(token) } noexcept;
-} && ::std::copyable<Token> && ::std::equality_comparable<Token> && ::std::swappable<Token>;
-} // namespace beman::execution
-
-#line 15 "include/beman/execution/detail/completion_tag.hpp"
-namespace beman::execution::detail {
-
-#line 21 "include/beman/execution/detail/completion_tag.hpp"
-template <typename Tag>
-concept completion_tag =
-    ::std::same_as<Tag, ::beman::execution::set_error_t> || ::std::same_as<Tag, ::beman::execution::set_stopped_t> ||
-    ::std::same_as<Tag, ::beman::execution::set_value_t>;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/await_result_type.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/await_result_type.hpp"
-export /* --------- */ template <typename T, typename Promise>
-using await_result_type =
-    decltype(::beman::execution::detail::get_awaiter(::std::declval<T>(), ::std::declval<Promise&>()).await_resume());
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/fwd_env.hpp"
-namespace beman::execution::detail {
-
-#line 22 "include/beman/execution/detail/fwd_env.hpp"
-export /* --------- */ template <typename Env>
-class fwd_env {
-  private:
-    Env env;
-
-  public:
-    explicit fwd_env(Env&& e) : env(::std::forward<Env>(e)) {}
-
-    template <typename Query, typename... Args>
-        requires(!::beman::execution::forwarding_query(::std::remove_cvref_t<Query>()))
-    constexpr auto query(Query&& q,
-                         Args&&... args) const = BEMAN_EXECUTION_DELETE("the used query is not forwardable");
-
-    template <typename Query, typename... Args>
-        requires(::beman::execution::forwarding_query(::std::remove_cvref_t<Query>())) &&
-                requires(const Env& e, Query&& q, Args&&... args) { e.query(q, ::std::forward<Args>(args)...); }
-    constexpr auto query(Query&& q, Args&&... args) const
-        noexcept(noexcept(env.query(q, ::std::forward<Args>(args)...))) {
-        return env.query(q, ::std::forward<Args>(args)...);
-    }
-};
-template <typename Env>
-fwd_env(Env&&) -> fwd_env<Env>;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/tag_of_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Sender>
-using tag_of_t = typename decltype(::beman::execution::detail::get_sender_meta(::std::declval<Sender&&>()))::tag_type;
-}
-#line 13 "include/beman/execution/detail/meta_combine.hpp"
-namespace beman::execution::detail::meta::detail {
-template <typename...>
-struct combine;
-
-template <template <typename...> class L0, typename... T0>
-struct combine<L0<T0...>> {
-    using type = L0<T0...>;
-};
-template <template <typename...> class L0,
-          typename... T0,
-          template <typename...> class L1,
-          typename... T1,
-          typename... L>
-struct combine<L0<T0...>, L1<T1...>, L...> {
-    using type = typename combine<L0<T0..., T1...>, L...>::type;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <typename... L>
-using combine = typename ::beman::execution::detail::meta::detail::combine<L...>::type;
-}
-#line 15 "include/beman/execution/detail/meta_unique.hpp"
-namespace beman::execution::detail::meta::detail {
-template <typename, typename>
-struct make_unique;
-template <typename>
-struct unique;
-
-template <template <typename...> class List, typename... R>
-struct make_unique<List<R...>, List<>> {
-    using type = List<R...>;
-};
-
-template <template <typename...> class List, typename... R, typename H, typename... T>
-struct make_unique<List<R...>, List<H, T...>> {
-    using type = typename ::beman::execution::detail::meta::detail::make_unique<
-        ::std::conditional_t<::beman::execution::detail::meta::contains<H, R...>, List<R...>, List<R..., H>>,
-        List<T...>>::type;
-};
-
-template <template <typename...> class List, typename... T>
-struct unique<List<T...>> {
-    using type = typename ::beman::execution::detail::meta::detail::make_unique<List<>, List<T...>>::type;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <typename T>
-using unique = typename ::beman::execution::detail::meta::detail::unique<T>::type;
-}
-#line 13 "include/beman/execution/detail/meta_filter.hpp"
-namespace beman::execution::detail::meta::detail {
-template <template <typename> class, typename>
-struct filter;
-
-template <template <typename, typename> class, typename, typename>
-struct filter_tag;
-
-template <template <typename> class Predicate, template <typename...> class List>
-struct filter<Predicate, List<>> {
-    using type = List<>;
-};
-
-template <template <typename, typename> class Predicate, typename Tag, template <typename...> class List>
-struct filter_tag<Predicate, Tag, List<>> {
-    using type = List<>;
-};
-
-template <template <typename> class Predicate, template <typename...> class List, typename H, typename... T>
-struct filter<Predicate, List<H, T...>> {
-    using tail = typename beman::execution::detail::meta::detail::filter<Predicate, List<T...>>::type;
-    using type = ::std::conditional_t<Predicate<H>::value, ::beman::execution::detail::meta::prepend<H, tail>, tail>;
-};
-
-template <template <typename, typename> class Predicate,
-          typename Tag,
-          template <typename...> class List,
-          typename H,
-          typename... T>
-struct filter_tag<Predicate, Tag, List<H, T...>> {
-    using tail = typename beman::execution::detail::meta::detail::filter_tag<Predicate, Tag, List<T...>>::type;
-    using type =
-        ::std::conditional_t<Predicate<Tag, H>::value, ::beman::execution::detail::meta::prepend<H, tail>, tail>;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <template <typename> class Predicate, typename List>
-using filter = typename ::beman::execution::detail::meta::detail::filter<Predicate, List>::type;
-
-template <template <typename, typename> class Predicate, typename Tag, typename List>
-using filter_tag = typename ::beman::execution::detail::meta::detail::filter_tag<Predicate, Tag, List>::type;
-} // namespace beman::execution::detail::meta
-
-#line 12 "include/beman/execution/detail/meta_transform.hpp"
-namespace beman::execution::detail::meta::detail {
-template <template <typename> class Transform, typename List>
-struct transform;
-
-template <template <typename> class Transform, template <typename... T> class List, typename... T>
-struct transform<Transform, List<T...>> {
-    using type = List<Transform<T>...>;
-};
-} // namespace beman::execution::detail::meta::detail
-
-namespace beman::execution::detail::meta {
-template <template <typename> class Transform, typename List>
-using transform = typename ::beman::execution::detail::meta::detail::transform<Transform, List>::type;
-}
-#line 12 "include/beman/execution/detail/as_tuple.hpp"
-namespace beman::execution::detail {
-
-#line 17 "include/beman/execution/detail/as_tuple.hpp"
-template <typename T>
-struct as_tuple;
-
-#line 23 "include/beman/execution/detail/as_tuple.hpp"
-template <typename Rc, typename... A>
-struct as_tuple<Rc(A...)> {
-    using type = ::beman::execution::detail::decayed_tuple<Rc, A...>;
-};
-
-template <typename T>
-using as_tuple_t = typename ::beman::execution::detail::as_tuple<T>::type;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-namespace beman::execution::detail {
-
-template <auto Next>
-class atomic_intrusive_stack;
-
-#line 35 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-template <class Item, Item* Item::* Next>
-class atomic_intrusive_stack<Next> {
-  public:
-    atomic_intrusive_stack() = default;
-    ~atomic_intrusive_stack() { assert(!head_ || head_ == this); }
-    atomic_intrusive_stack(const atomic_intrusive_stack&)                        = delete;
-    auto operator=(const atomic_intrusive_stack&) -> atomic_intrusive_stack&     = delete;
-    atomic_intrusive_stack(atomic_intrusive_stack&&) noexcept                    = delete;
-    auto operator=(atomic_intrusive_stack&&) noexcept -> atomic_intrusive_stack& = delete;
-
-#line 51 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-    auto try_push(Item* item) noexcept -> std::optional<Item*> {
-        void* ptr = head_.load();
-        if (ptr == this) {
-            return std::nullopt;
-        }
-        item->*Next = static_cast<Item*>(ptr);
-        while (!head_.compare_exchange_weak(ptr, item)) {
-            if (ptr == this) {
-                return std::nullopt;
-            }
-            item->*Next = static_cast<Item*>(ptr);
-        }
-        return static_cast<Item*>(ptr);
-    }
-#line 67 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-    auto empty_and_not_shutdown() const noexcept -> bool { return head_.load() == nullptr; }
-
-#line 72 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-    auto pop_all_and_shutdown() noexcept -> ::beman::execution::detail::intrusive_stack<Next> {
-        auto  stack = ::beman::execution::detail::intrusive_stack<Next>{};
-        void* ptr   = head_.exchange(this);
-        if (ptr == this) {
-            return stack;
-        }
-        auto item   = static_cast<Item*>(ptr);
-        stack.head_ = item;
-        return stack;
-    }
-#line 83 "include/beman/execution/detail/atomic_intrusive_stack.hpp"
-  private:
-    ::std::atomic<void*> head_{nullptr};
-};
-
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/inplace_stop_source.hpp"
-namespace beman::execution {
-export /* --------- */ class inplace_stop_token;
-export /* --------- */ class inplace_stop_source;
-export /* --------- */ template <typename CallbackFun>
-class inplace_stop_callback;
-export /* --------- */ template <typename CallbackFun>
-inplace_stop_callback(::beman::execution::inplace_stop_token, CallbackFun) -> inplace_stop_callback<CallbackFun>;
-} // namespace beman::execution
-
-#line 28 "include/beman/execution/detail/inplace_stop_source.hpp"
-class beman::execution::inplace_stop_token {
-  public:
-    template <typename CallbackFun>
-    using callback_type = ::beman::execution::inplace_stop_callback<CallbackFun>;
-
-    inplace_stop_token() = default;
-
-    constexpr auto stop_requested() const noexcept -> bool;
-    constexpr auto stop_possible() const noexcept -> bool;
-    auto           operator==(const inplace_stop_token&) const -> bool = default;
-
-    auto swap(inplace_stop_token&) noexcept -> void;
-
-  private:
-    friend class ::beman::execution::inplace_stop_source;
-    template <typename CallbackFun>
-    friend class ::beman::execution::inplace_stop_callback;
-    explicit inplace_stop_token(::beman::execution::inplace_stop_source* src) : source(src) {}
-
-    ::beman::execution::inplace_stop_source* source{};
-};
-
-#line 52 "include/beman/execution/detail/inplace_stop_source.hpp"
-class beman::execution::inplace_stop_source {
-    struct callback_base : public ::beman::execution::detail::virtual_immovable {
-        callback_base* next{};
-        virtual auto   call() -> void = 0;
-    };
-
-  public:
-    auto                  stop_requested() const noexcept -> bool;
-    static constexpr auto stop_possible() noexcept -> bool;
-    auto                  get_token() const -> ::beman::execution::inplace_stop_token;
-
-    auto request_stop() -> bool;
-
-  private:
-    template <typename CallbackFun>
-    friend class ::beman::execution::inplace_stop_callback;
-    ::std::atomic<bool>           stopped{};
-    ::std::atomic<callback_base*> running{};
-    ::std::thread::id             id{};
-    ::std::mutex                  lock;
-    callback_base*                callbacks{};
-
-    auto add(callback_base* cb) -> void;
-    auto deregister(callback_base* cb) -> void;
-};
-
-#line 80 "include/beman/execution/detail/inplace_stop_source.hpp"
-template <typename CallbackFun>
-class beman::execution::inplace_stop_callback final : public ::beman::execution::inplace_stop_source::callback_base {
-  public:
-    using callback_type = CallbackFun;
-
-    template <typename Init>
-    inplace_stop_callback(::beman::execution::inplace_stop_token, Init&&);
-    inplace_stop_callback(const inplace_stop_callback&) = delete;
-    inplace_stop_callback(inplace_stop_callback&&)      = delete;
-    ~inplace_stop_callback() override {
-        if (this->source) {
-            this->source->deregister(this);
-        }
-    }
-    auto operator=(const inplace_stop_callback&) -> inplace_stop_callback& = delete;
-    auto operator=(inplace_stop_callback&&) -> inplace_stop_callback&      = delete;
-
-  private:
-    auto call() -> void override;
-
-    CallbackFun                              fun;
-    ::beman::execution::inplace_stop_source* source;
-};
-
-#line 106 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline constexpr auto beman::execution::inplace_stop_token::stop_requested() const noexcept -> bool {
-    return this->source && this->source->stop_requested();
-}
-#line 110 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline constexpr auto beman::execution::inplace_stop_token::stop_possible() const noexcept -> bool {
-    return this->source;
-}
-#line 114 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_token::swap(inplace_stop_token& other) noexcept -> void {
-    ::std::swap(this->source, other.source);
-}
-#line 118 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_source::stop_requested() const noexcept -> bool { return this->stopped; }
-
-inline constexpr auto beman::execution::inplace_stop_source::stop_possible() noexcept -> bool { return true; }
-
-inline auto beman::execution::inplace_stop_source::get_token() const -> ::beman::execution::inplace_stop_token {
-    return ::beman::execution::inplace_stop_token(const_cast<::beman::execution::inplace_stop_source*>(this));
-}
-#line 126 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_source::request_stop() -> bool {
-    using relock = ::std::unique_ptr<::std::unique_lock<::std::mutex>, decltype([](auto p) { p->lock(); })>;
-    if (false == this->stopped.exchange(true)) {
-        ::std::unique_lock guard(this->lock);
-        for (auto it = this->callbacks; it != nullptr; it = this->callbacks) {
-            this->running   = it;
-            this->id        = ::std::this_thread::get_id();
-            this->callbacks = it->next;
-            {
-                relock r(&guard);
-                guard.unlock();
-                it->call();
-            }
-            this->running = nullptr;
-        }
-        return true;
-    }
-    return false;
-}
-#line 146 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_source::add(callback_base* cb) -> void {
-    if (this->stopped) {
-        cb->call();
-    } else {
-        ::std::lock_guard guard(this->lock);
-        cb->next = ::std::exchange(this->callbacks, cb);
-    }
-}
-#line 155 "include/beman/execution/detail/inplace_stop_source.hpp"
-inline auto beman::execution::inplace_stop_source::deregister(callback_base* cb) -> void {
-    ::std::unique_lock guard(this->lock);
-    if (this->running == cb) {
-        if (this->id == ::std::this_thread::get_id()) {
-            return;
-        }
-        guard.unlock();
-        while (this->running == cb) {
-        }
-        return;
-    }
-#line 167 "include/beman/execution/detail/inplace_stop_source.hpp"
-    for (callback_base** it{&this->callbacks}; *it; it = &(*it)->next) {
-        if (*it == cb) {
-            *it = cb->next;
-            break;
-        }
-    }
-}
-#line 175 "include/beman/execution/detail/inplace_stop_source.hpp"
-template <typename CallbackFun>
-template <typename Init>
-inline beman::execution::inplace_stop_callback<CallbackFun>::inplace_stop_callback(
-    ::beman::execution::inplace_stop_token token, Init&& init)
-    : fun(::std::forward<Init>(init)), source(token.source) {
-    if (this->source) {
-        this->source->add(this);
-    }
-}
-#line 185 "include/beman/execution/detail/inplace_stop_source.hpp"
-template <typename CallbackFun>
-inline auto beman::execution::inplace_stop_callback<CallbackFun>::call() -> void {
-    this->fun();
-}
-#line 13 "include/beman/execution/detail/decayed_type_list.hpp"
-namespace beman::execution::detail {
-template <class... Args>
-using decayed_type_list = ::beman::execution::detail::type_list<::std::decay_t<Args>...>;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/class_type.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/class_type.hpp"
-template <typename Tp>
-concept class_type = ::beman::execution::detail::decays_to<Tp, Tp> && ::std::is_class_v<Tp>;
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/nothrow_callable.hpp"
-namespace beman::execution::detail {
-template <typename Fun, typename... Args>
-concept nothrow_callable = ::beman::execution::detail::callable<Fun, Args...> && requires(Fun&& fun, Args&&... args) {
-    { ::std::forward<Fun>(fun)(::std::forward<Args>(args)...) } noexcept;
-};
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/counting_scope_base.hpp"
-namespace beman::execution::detail {
-class counting_scope_base;
-}
-#line 22 "include/beman/execution/detail/counting_scope_base.hpp"
-class beman::execution::detail::counting_scope_base : ::beman::execution::detail::immovable {
-  public:
-    counting_scope_base()                      = default;
-    counting_scope_base(counting_scope_base&&) = delete;
-    ~counting_scope_base();
-
-    static constexpr ::std::size_t max_associations{8194u};
-
-    auto close() noexcept -> void;
-
-    struct node {
-        virtual auto complete() noexcept -> void        = 0;
-        virtual auto complete_inline() noexcept -> void = 0;
-        node*        next{};
-    };
-    auto start_node(node*) -> void;
-
-  protected:
-    class token {
-      public:
-        auto try_associate() const noexcept -> bool { return this->scope->try_associate(); }
-        auto disassociate() const noexcept -> void { this->scope->disassociate(); }
-
-      protected:
-        explicit token(::beman::execution::detail::counting_scope_base* s) : scope(s) {}
-        ::beman::execution::detail::counting_scope_base* scope;
-    };
-
-  private:
-    enum class state_t : unsigned char {
-        unused,
-        open,
-        open_and_joining,
-        closed,
-        closed_and_joining,
-        unused_and_closed,
-        joined
-    };
-
-    auto try_associate() noexcept -> bool;
-    auto disassociate() noexcept -> void;
-    auto complete() noexcept -> void;
-    auto add_node(node* n, ::std::lock_guard<::std::mutex>&) noexcept -> void;
-
-    ::std::mutex mutex;
-
-    ::std::size_t count{};
-    state_t       state{state_t::unused};
-    node*         head{};
-};
-
-#line 75 "include/beman/execution/detail/counting_scope_base.hpp"
-inline beman::execution::detail::counting_scope_base::~counting_scope_base() {
-    ::std::lock_guard kerberos(this->mutex);
-    switch (this->state) {
-    default:
-        ::std::terminate();
-    case state_t::unused:
-    case state_t::unused_and_closed:
-    case state_t::joined:
-        break;
-    }
-}
-#line 87 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::close() noexcept -> void {
-    switch (this->state) {
-    default:
-        break;
-    case state_t::unused:
-        this->state = state_t::unused_and_closed;
-        break;
-    case state_t::open:
-        this->state = state_t::closed;
-        break;
-    case state_t::open_and_joining:
-        this->state = state_t::closed_and_joining;
-        break;
-    }
-}
-#line 103 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::add_node(node* n, ::std::lock_guard<::std::mutex>&) noexcept
-    -> void {
-    n->next = std::exchange(this->head, n);
-}
-#line 108 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::try_associate() noexcept -> bool {
-    ::std::lock_guard lock(this->mutex);
-    switch (this->state) {
-    default:
-        return false;
-    case state_t::unused:
-        this->state = state_t::open;
-        [[fallthrough]];
-    case state_t::open:
-    case state_t::open_and_joining:
-        ++this->count;
-        return true;
-    }
-}
-#line 123 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::disassociate() noexcept -> void {
-    {
-        ::std::lock_guard lock(this->mutex);
-        if (0u < --this->count)
-            return;
-        this->state = state_t::joined;
-    }
-    this->complete();
-}
-#line 133 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::complete() noexcept -> void {
-    node* current{[this] {
-        ::std::lock_guard lock(this->mutex);
-        return ::std::exchange(this->head, nullptr);
-    }()};
-    while (current) {
-        ::std::exchange(current, current->next)->complete();
-    }
-}
-#line 143 "include/beman/execution/detail/counting_scope_base.hpp"
-inline auto beman::execution::detail::counting_scope_base::start_node(node* n) -> void {
-    ::std::lock_guard kerberos(this->mutex);
-    switch (this->state) {
-    case ::beman::execution::detail::counting_scope_base::state_t::unused:
-    case ::beman::execution::detail::counting_scope_base::state_t::unused_and_closed:
-    case ::beman::execution::detail::counting_scope_base::state_t::joined:
-        this->state = ::beman::execution::detail::counting_scope_base::state_t::joined;
-        n->complete_inline();
-        return;
-    case ::beman::execution::detail::counting_scope_base::state_t::open:
-        this->state = ::beman::execution::detail::counting_scope_base::state_t::open_and_joining;
-        break;
-    case ::beman::execution::detail::counting_scope_base::state_t::open_and_joining:
-        break;
-    case ::beman::execution::detail::counting_scope_base::state_t::closed:
-        this->state = ::beman::execution::detail::counting_scope_base::state_t::closed_and_joining;
-        break;
-    case ::beman::execution::detail::counting_scope_base::state_t::closed_and_joining:
-        break;
-    }
-    this->add_node(n, kerberos);
-}
-#line 13 "include/beman/execution/detail/is_awaiter.hpp"
-namespace beman::execution::detail {
-template <typename Awaiter, typename Promise>
-concept is_awaiter = requires(Awaiter& awaiter, ::std::coroutine_handle<Promise> handle) {
-    awaiter.await_ready() ? 1 : 0;
-    { awaiter.await_suspend(handle) } -> ::beman::execution::detail::await_suspend_result;
-    awaiter.await_resume();
-};
-} // namespace beman::execution::detail
-
-#line 18 "include/beman/execution/detail/stop_source.hpp"
-namespace beman::execution {
-export /* --------- */ class stop_token;
-export /* --------- */ class stop_source;
-export /* --------- */ template <typename CallbackFun>
-class stop_callback;
-export /* --------- */ template <typename CallbackFun>
-stop_callback(::beman::execution::stop_token, CallbackFun) -> stop_callback<CallbackFun>;
-} // namespace beman::execution
-
-namespace beman::execution::detail {
-struct stop_state;
-struct stop_callback_base;
-} // namespace beman::execution::detail
-
-#line 33 "include/beman/execution/detail/stop_source.hpp"
-struct beman::execution::detail::stop_state {
-    ::std::atomic<bool>                           stop_requested{};
-    ::std::atomic<::std::size_t>                  sources{};
-    ::std::mutex                                  lock{};
-    beman::execution::detail::stop_callback_base* callbacks{};
-    ::std::atomic<bool>                           executing{};
-
-    auto stop_possible() const -> bool { return this->sources != 0 || this->stop_requested; }
-};
-
-#line 45 "include/beman/execution/detail/stop_source.hpp"
-struct beman::execution::detail::stop_callback_base {
-  private:
-    using stop_state = ::beman::execution::detail::stop_state;
-    ::std::shared_ptr<stop_state> state;
-
-    virtual auto do_call() -> void = 0;
-
-  protected:
-    explicit stop_callback_base(const ::beman::execution::stop_token&);
-    ~stop_callback_base();
-
-  public:
-    stop_callback_base(stop_callback_base&&)                         = delete;
-    stop_callback_base(const stop_callback_base&)                    = delete;
-    auto operator=(stop_callback_base&&) -> stop_callback_base&      = delete;
-    auto operator=(const stop_callback_base&) -> stop_callback_base& = delete;
-    auto call() -> void;
-    auto setup() -> void;
-    auto deregister() -> void;
-
-    stop_callback_base* next{};
-    ::std::thread::id   id{};
-};
-
-#line 71 "include/beman/execution/detail/stop_source.hpp"
-class beman::execution::stop_source {
-  private:
-    using stop_state = ::beman::execution::detail::stop_state;
-
-    ::std::shared_ptr<stop_state> state{::std::make_shared<stop_state>()};
-
-  public:
-    using stop_token = ::beman::execution::stop_token;
-
-    stop_source();
-    explicit stop_source(::beman::execution::nostopstate_t) noexcept;
-    stop_source(const stop_source&);
-    stop_source(stop_source&&) = default;
-    auto operator=(const stop_source&) -> stop_source&;
-    auto operator=(stop_source&&) -> stop_source& = default;
-    ~stop_source();
-
-    auto swap(stop_source&) noexcept -> void;
-    auto get_token() const -> stop_token;
-    auto stop_requested() const noexcept -> bool;
-    auto stop_possible() const noexcept -> bool;
-    auto request_stop() noexcept -> bool;
-};
-
-#line 97 "include/beman/execution/detail/stop_source.hpp"
-class beman::execution::stop_token {
-  private:
-    friend ::beman::execution::stop_source;
-    friend ::beman::execution::detail::stop_callback_base;
-    ::std::shared_ptr<::beman::execution::detail::stop_state> state;
-
-    explicit stop_token(::std::shared_ptr<::beman::execution::detail::stop_state>);
-
-  public:
-    template <typename Fun>
-    using callback_type = ::beman::execution::stop_callback<Fun>;
-
-    stop_token() = default;
-
-    auto               swap(stop_token& other) noexcept -> void;
-    [[nodiscard]] auto stop_requested() const noexcept -> bool;
-    [[nodiscard]] auto stop_possible() const noexcept -> bool;
-
-    [[nodiscard]] auto operator==(const stop_token&) const noexcept -> bool = default;
-};
-
-#line 120 "include/beman/execution/detail/stop_source.hpp"
-template <typename CallbackFun>
-class beman::execution::stop_callback final : private CallbackFun, beman::execution::detail::stop_callback_base {
-  private:
-    static_assert(::std::invocable<CallbackFun>);
-    static_assert(::std::destructible<CallbackFun>);
-
-    using stop_token = ::beman::execution::stop_token;
-
-    auto do_call() -> void override { (*this)(); }
-
-  public:
-    using callback_type = CallbackFun;
-
-    template <typename Initializer>
-    stop_callback(const stop_token& token,
-                  Initializer&&     init) noexcept(::std::is_nothrow_constructible_v<CallbackFun, Initializer>)
-        requires(::std::constructible_from<CallbackFun, Initializer>)
-        : CallbackFun(::std::forward<Initializer>(init)), stop_callback_base(token) {
-        this->setup();
-    }
-    template <typename Initializer>
-    stop_callback(stop_token&&  token,
-                  Initializer&& init) noexcept(::std::is_nothrow_constructible_v<CallbackFun, Initializer>)
-        requires(::std::is_constructible_v<CallbackFun, Initializer>)
-        : CallbackFun(::std::forward<Initializer>(init)), stop_callback_base(::std::move(token)) {
-        this->setup();
-    }
-    stop_callback(const stop_callback&) = delete;
-    stop_callback(stop_callback&&)      = delete;
-    ~stop_callback() { this->deregister(); }
-    auto operator=(stop_callback&&) -> stop_callback&      = delete;
-    auto operator=(const stop_callback&) -> stop_callback& = delete;
-};
-
-#line 156 "include/beman/execution/detail/stop_source.hpp"
-inline beman::execution::detail::stop_callback_base::stop_callback_base(const ::beman::execution::stop_token& token)
-    : state(token.state) {}
-
-inline beman::execution::detail::stop_callback_base::~stop_callback_base() {}
-
-inline auto beman::execution::detail::stop_callback_base::setup() -> void {
-    if (this->state) {
-        {
-            ::std::lock_guard guard(this->state->lock);
-            if (!this->state->stop_requested) {
-                this->next = ::std::exchange(this->state->callbacks, this);
-                return;
-            }
-        }
-        this->call();
-    }
-}
-#line 174 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::detail::stop_callback_base::deregister() -> void {
-    if (this->state) {
-        ::std::unique_lock guard(this->state->lock);
-        if (this->state->executing && this->id != ::std::this_thread::get_id()) {
-            using lock_again = decltype([](auto p) { p->lock(); });
-            ::std::unique_ptr<decltype(guard), lock_again> relock(&guard);
-            relock->unlock();
-            while (this->state->executing)
-                ;
-        }
-        for (auto n = &this->state->callbacks; *n; n = &this->next) {
-            if (*n == this) {
-                *n = this->next;
-                break;
-            }
-        }
-    }
-}
-#line 193 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::detail::stop_callback_base::call() -> void { this->do_call(); }
-
-inline beman::execution::stop_token::stop_token(::std::shared_ptr<::beman::execution::detail::stop_state> st)
-    : state(::std::move(st)) {}
-
-inline auto beman::execution::stop_token::swap(stop_token& other) noexcept -> void { this->state.swap(other.state); }
-
-inline auto beman::execution::stop_token::stop_requested() const noexcept -> bool {
-    return this->state && this->state->stop_requested;
-}
-#line 204 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::stop_token::stop_possible() const noexcept -> bool {
-    return this->state && this->state->stop_possible();
-}
-#line 210 "include/beman/execution/detail/stop_source.hpp"
-inline beman::execution::stop_source::stop_source() { ++this->state->sources; }
-
-inline beman::execution::stop_source::stop_source(::beman::execution::nostopstate_t) noexcept : state() {}
-
-inline beman::execution::stop_source::stop_source(const stop_source& other) : state(other.state) {
-    ++this->state->sources;
-}
-#line 218 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::stop_source::operator=(const stop_source& other) -> stop_source& {
-    stop_source(other).swap(*this);
-    return *this;
-}
-#line 223 "include/beman/execution/detail/stop_source.hpp"
-inline beman::execution::stop_source::~stop_source() { this->state && --this->state->sources; }
-
-inline auto beman::execution::stop_source::swap(::beman::execution::stop_source& other) noexcept -> void {
-    this->state.swap(other.state);
-}
-#line 229 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::stop_source::get_token() const -> stop_token { return stop_token{this->state}; }
-
-inline auto beman::execution::stop_source::stop_requested() const noexcept -> bool {
-    return this->state && this->state->stop_requested;
-}
-#line 235 "include/beman/execution/detail/stop_source.hpp"
-inline auto beman::execution::stop_source::stop_possible() const noexcept -> bool { return true && this->state; }
-
-inline auto beman::execution::stop_source::request_stop() noexcept -> bool {
-    using release    = decltype([](auto p) { *p = false; });
-    using lock_again = decltype([](auto p) { p->lock(); });
-
-    if (this->state && not this->state->stop_requested.exchange(true)) {
-        ::std::unique_lock guard(this->state->lock);
-        while (this->state->callbacks) {
-            auto front = ::std::exchange(this->state->callbacks, this->state->callbacks->next);
-            ::std::unique_ptr<::std::atomic<bool>, release> reset(&state->executing);
-            *reset    = true;
-            front->id = ::std::this_thread::get_id();
-            ::std::unique_ptr<decltype(guard), lock_again> relock(&guard);
-            relock->unlock();
-            front->call();
-        }
-        return true;
-    }
-    return false;
-}
-#line 16 "include/beman/execution/detail/get_stop_token.hpp"
-namespace beman::execution::detail {
-template <typename Token>
-concept decayed_stoppable_token = ::beman::execution::stoppable_token<::std::decay_t<Token>>;
-}
-namespace beman::execution {
-export /* --------- */ struct get_stop_token_t {
-    template <typename Object>
-        requires requires(Object&& object, const get_stop_token_t& tag) {
-            { ::std::as_const(object).query(tag) } noexcept -> ::beman::execution::detail::decayed_stoppable_token;
-        }
-    auto operator()(Object&& object) const noexcept {
-        return ::std::as_const(object).query(*this);
-    }
-#line 30 "include/beman/execution/detail/get_stop_token.hpp"
-    template <typename Object>
-    auto operator()(Object&&) const noexcept -> ::beman::execution::never_stop_token {
-        return {};
-    }
-#line 35 "include/beman/execution/detail/get_stop_token.hpp"
-    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
-};
-
-export /* --------- */ inline constexpr get_stop_token_t get_stop_token{};
-} // namespace beman::execution
-
-#line 15 "include/beman/execution/detail/get_env.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_env_t {
-    template <typename Object>
-        requires(not requires(::std::add_const_t<::std::remove_cvref_t<Object>>& object) { object.get_env(); } ||
-                 ::beman::execution::detail::queryable<
-                     std::remove_cvref_t<decltype(::std::declval<const ::std::remove_cvref_t<Object>&>().get_env())>>)
-    auto operator()(Object&& object) const noexcept -> decltype(auto) {
-        ::std::add_const_t<::std::remove_cvref_t<Object>>& obj{object};
-        if constexpr (requires { obj.get_env(); }) {
-            static_assert(noexcept(obj.get_env()), "get_env requires the expression to be noexcept");
-            static_assert(::beman::execution::detail::queryable<std::remove_cvref_t<decltype(obj.get_env())>>,
-                          "get_env requires the result type to be destructible");
-            return obj.get_env();
-        } else {
-            return ::beman::execution::env<>{};
-        }
-    }
-};
-
-export /* --------- */ inline constexpr get_env_t get_env{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/completion_signatures.hpp"
-namespace beman::execution {
-
-#line 24 "include/beman/execution/detail/completion_signatures.hpp"
-export /* --------- */ template <::beman::execution::detail::completion_signature...>
-struct completion_signatures {};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/is_awaitable.hpp"
-namespace beman::execution::detail {
-template <typename T, typename Promise>
-concept is_awaitable = requires(Promise& promise) {
-    {
-        ::beman::execution::detail::get_awaiter(::std::declval<T>(), promise)
-    } -> ::beman::execution::detail::is_awaiter<Promise>;
-};
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/emplace_from.hpp"
-namespace beman::execution::detail {
-
-#line 21 "include/beman/execution/detail/emplace_from.hpp"
-template <typename Fun>
-struct emplace_from {
-    using type = ::beman::execution::detail::call_result_t<Fun>;
-    Fun fun;
-
-    explicit constexpr operator type() && noexcept(::beman::execution::detail::nothrow_callable<Fun>) {
-        return ::std::move(fun)();
-    }
-};
-template <typename Fun>
-emplace_from(Fun&&) -> emplace_from<::std::remove_cvref_t<Fun>>;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/variant_or_empty.hpp"
-namespace beman::execution::detail {
-struct empty_variant {
-    empty_variant() = delete;
-};
-
-template <typename... T>
-struct variant_or_empty_helper;
-
-template <>
-struct variant_or_empty_helper<> {
-    using type = ::beman::execution::detail::empty_variant;
-};
-
-template <typename... T>
-struct variant_or_empty_helper {
-    using type = ::beman::execution::detail::meta::unique<::std::variant<::std::decay_t<T>...>>;
-};
-
-template <typename... T>
-using variant_or_empty = typename ::beman::execution::detail::variant_or_empty_helper<T...>::type;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/stoppable_source.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <typename Source>
-concept stoppable_source = requires(Source& source, const Source& csource) {
-    { csource.get_token() } -> ::beman::execution::stoppable_token;
-    { csource.stop_possible() } noexcept -> ::std::same_as<bool>;
-    { csource.stop_requested() } noexcept -> ::std::same_as<bool>;
-    { source.request_stop() } -> ::std::same_as<bool>;
-};
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/receiver.hpp"
-namespace beman::execution {
-export /* --------- */ struct receiver_t {};
-
-export /* --------- */ template <typename Rcvr>
-concept receiver =
-    ::std::derived_from<typename ::std::remove_cvref_t<Rcvr>::receiver_concept, ::beman::execution::receiver_t> &&
-    requires(const ::std::remove_cvref_t<Rcvr>& rcvr) {
-        { ::beman::execution::get_env(rcvr) } -> ::beman::execution::detail::queryable;
-    } && ::std::move_constructible<::std::remove_cvref_t<Rcvr>> &&
-    ::std::constructible_from<::std::remove_cvref_t<Rcvr>, Rcvr> && (!::std::is_final_v<::std::remove_cvref_t<Rcvr>>);
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/valid_completion_signatures.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct valid_completion_signatures_helper : ::std::false_type {};
-template <typename... Sigs>
-struct valid_completion_signatures_helper<::beman::execution::completion_signatures<Sigs...>> : ::std::true_type {};
-
-template <typename Signatures>
-concept valid_completion_signatures = valid_completion_signatures_helper<Signatures>::value;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/env_of_t.hpp"
-namespace beman::execution {
-
-#line 18 "include/beman/execution/detail/env_of_t.hpp"
-export /* --------- */ template <typename T>
-using env_of_t = decltype(::beman::execution::get_env(::std::declval<T>()));
-} // namespace beman::execution
-
-#line 17 "include/beman/execution/detail/allocator_aware_move.hpp"
-namespace beman::execution::detail {
-template <typename T, typename Context>
-
-#line 24 "include/beman/execution/detail/allocator_aware_move.hpp"
-auto allocator_aware_move(T&& obj, Context&& context) noexcept -> decltype(auto) {
-    try {
-        if constexpr (requires { ::beman::execution::get_allocator(::beman::execution::get_env(context)); }) {
-            if constexpr (decltype(::beman::execution::detail::is_product_type(obj))()) {
-                return obj.make_from(::beman::execution::get_allocator(::beman::execution::get_env(context)),
-                                     ::std::forward<T>(obj));
-            } else {
-                return ::std::make_obj_using_allocator<T>(
-                    ::beman::execution::get_allocator(::beman::execution::get_env(context)), ::std::forward<T>(obj));
-            }
-        } else {
-            return ::std::forward<T>(obj);
-        }
-    } catch (...) {
-        ::std::terminate();
-    }
-}
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/stop_token_of_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename T>
-using stop_token_of_t = ::std::remove_cvref_t<decltype(::beman::execution::get_stop_token(::std::declval<T>()))>;
-}
-#line 13 "include/beman/execution/detail/unstoppable_token.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Token>
-concept unstoppable_token = ::beman::execution::stoppable_token<Token> &&
-                            requires() { requires ::std::bool_constant<not Token::stop_possible()>::value; };
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/has_as_awaitable.hpp"
-namespace beman::execution::detail {
-template <typename T, typename Promise>
-concept has_as_awaitable = requires(T&& obj, Promise& promise) {
-    { ::std::forward<T>(obj).as_awaitable(promise) } -> ::beman::execution::detail::is_awaitable<Promise&>;
-};
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/has_completions.hpp"
-namespace beman::execution::detail {
-template <typename Receiver, typename Completions>
-concept has_completions = requires(Completions* completions) {
-    []<::beman::execution::detail::valid_completion_for<Receiver>... Signatures>(
-        ::beman::execution::completion_signatures<Signatures...>*) {}(completions);
-};
-} // namespace beman::execution::detail
-
-#line 23 "include/beman/execution/detail/default_impls.hpp"
-namespace beman::execution::detail {
-
-#line 29 "include/beman/execution/detail/default_impls.hpp"
-struct default_impls {
-    struct get_attrs_impl {
-        auto operator()(const auto&, const auto&... child) const noexcept -> decltype(auto) {
-            if constexpr (1 == sizeof...(child))
-                return (::beman::execution::detail::fwd_env(::beman::execution::get_env(child)), ...);
-            else
-                return ::beman::execution::env<>{};
-        }
-    };
-    static constexpr auto get_attrs = get_attrs_impl{};
-    struct get_env_impl {
-        auto operator()(auto, auto&, const auto& receiver) const noexcept -> decltype(auto) {
-            return ::beman::execution::detail::fwd_env(::beman::execution::get_env(receiver));
-        }
-    };
-    static constexpr auto get_env = get_env_impl{};
-    struct get_state_impl {
-        template <typename Sender, typename Receiver>
-        auto operator()(Sender&& sender, Receiver& receiver) const noexcept -> decltype(auto) {
-            auto&& data{[&sender]() -> decltype(auto) {
-                if constexpr (requires {
-                                  sender.size();
-                                  sender.template get<1>();
-                              })
-                    return sender.template get<1>();
-                else
-                    return ::beman::execution::detail::get_sender_data(::std::forward<Sender>(sender)).data;
-            }()};
-
-            return ::beman::execution::detail::allocator_aware_move(
-                ::beman::execution::detail::forward_like<Sender>(data), receiver);
-        }
-    };
-    static constexpr auto get_state = get_state_impl{};
-    struct start_impl {
-        auto operator()(auto&, auto&, auto&... ops) const noexcept -> void { (::beman::execution::start(ops), ...); }
-    };
-    static constexpr auto start = start_impl{};
-    struct complete_impl {
-        template <typename Index, typename Receiver, typename Tag, typename... Args>
-            requires ::beman::execution::detail::callable<Tag, Receiver, Args...>
-        auto operator()(Index, auto&, Receiver& receiver, Tag, Args&&... args) const noexcept -> void {
-            static_assert(Index::value == 0);
-            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
-        }
-    };
-    static constexpr auto complete = complete_impl{};
-};
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/with_await_transform.hpp"
-namespace beman::execution::detail {
-// NOLINTBEGIN(bugprone-crtp-constructor-accessibility)
-template <typename Derived>
-struct with_await_transform {
-    template <typename T>
-    auto await_transform(T&& obj) noexcept -> T&& {
-        return ::std::forward<T>(obj);
-    }
-#line 23 "include/beman/execution/detail/with_await_transform.hpp"
-    template <::beman::execution::detail::has_as_awaitable<Derived> T>
-    auto await_transform(T&& obj) noexcept(noexcept(::std::forward<T>(obj).as_awaitable(::std::declval<Derived&>())))
-        -> decltype(auto) {
-        return ::std::forward<T>(obj).as_awaitable(static_cast<Derived&>(*this));
-    }
-};
-// NOLINTEND(bugprone-crtp-constructor-accessibility)
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/receiver_of.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Receiver, typename Completions>
-concept receiver_of =
-    beman::execution::receiver<Receiver> && beman::execution::detail::has_completions<Receiver, Completions>;
-}
-#line 15 "include/beman/execution/detail/gather_signatures.hpp"
-namespace beman::execution::detail {
-template <typename...>
-concept always_true = true;
-
-template <typename, typename>
-struct same_tag;
-template <typename Tag, typename R, typename... A>
-struct same_tag<Tag, R(A...)> {
-    static constexpr bool value = ::std::same_as<Tag, R>;
-};
-template <typename Tag>
-struct bound_tag {
-    using type = Tag;
-    template <typename T>
-    using predicate = ::beman::execution::detail::same_tag<Tag, T>;
-};
-
-template <typename, template <typename...> class>
-struct gather_signatures_apply;
-template <typename R, typename... A, template <typename...> class Transform>
-    requires requires {
-        typename ::beman::execution::detail::indirect_meta_apply<
-            ::beman::execution::detail::always_true<R>>::template meta_apply<Transform, A...>;
-    }
-struct gather_signatures_apply<R(A...), Transform> {
-    using type = typename ::beman::execution::detail::indirect_meta_apply<
-        ::beman::execution::detail::always_true<R>>::template meta_apply<Transform, A...>;
-};
-
-template <::beman::execution::detail::valid_completion_signatures,
-          template <typename...> class,
-          template <typename...> class>
-struct gather_signatures_helper;
-
-template <typename... Signatures, template <typename...> class Tuple, template <typename...> class Variant>
-    requires requires {
-        requires always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
-    } && requires {
-        typename ::beman::execution::detail::indirect_meta_apply<
-            always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>>::
-            template meta_apply<
-                Variant,
-                typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
-    }
-struct gather_signatures_helper<::beman::execution::completion_signatures<Signatures...>, Tuple, Variant> {
-    using type = typename ::beman::execution::detail::indirect_meta_apply<
-        always_true<typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>>::
-        template meta_apply<Variant,
-                            typename ::beman::execution::detail::gather_signatures_apply<Signatures, Tuple>::type...>;
-};
-
-template <typename Tag,
-          ::beman::execution::detail::valid_completion_signatures signatures,
-          template <typename...> class Tuple,
-          template <typename...> class Variant>
-    requires requires {
-        typename ::beman::execution::detail::gather_signatures_helper<
-            ::beman::execution::detail::meta::filter_tag<::beman::execution::detail::same_tag, Tag, signatures>,
-            Tuple,
-            Variant>::type;
-    }
-using gather_signatures = typename ::beman::execution::detail::gather_signatures_helper<
-    ::beman::execution::detail::meta::filter_tag<::beman::execution::detail::same_tag, Tag, signatures>,
-    Tuple,
-    Variant>::type;
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/env_promise.hpp"
-namespace beman::execution::detail {
-
-#line 19 "include/beman/execution/detail/env_promise.hpp"
-export /* --------- */ template <typename Env>
-struct env_promise : ::beman::execution::detail::with_await_transform<Env> {
-    auto get_return_object() noexcept -> void;
-    auto initial_suspend() noexcept -> ::std::suspend_always;
-    auto final_suspend() noexcept -> ::std::suspend_always;
-    auto unhandled_exception() noexcept -> void;
-    auto return_void() noexcept -> void;
-    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<>;
-    auto get_env() const noexcept -> const Env&;
-};
-} // namespace beman::execution::detail
-
-#line 12 "include/beman/execution/detail/impls_for.hpp"
-namespace beman::execution::detail {
-template <typename Tag>
-struct impls_for : ::beman::execution::detail::default_impls {};
-} // namespace beman::execution::detail
-
-#line 19 "include/beman/execution/detail/operation_state_task.hpp"
-namespace beman::execution::detail {
-template <typename Receiver>
-struct operation_state_task;
-
-template <typename Receiver>
-struct connect_awaitable_promise;
-} // namespace beman::execution::detail
-
-#line 29 "include/beman/execution/detail/operation_state_task.hpp"
-template <typename Receiver>
-struct beman::execution::detail::connect_awaitable_promise
-    : ::beman::execution::detail::with_await_transform<connect_awaitable_promise<Receiver>> {
-    connect_awaitable_promise(auto&&, Receiver& rcvr) noexcept : receiver(rcvr) {}
-    auto              initial_suspend() noexcept -> ::std::suspend_always { return {}; }
-    [[noreturn]] auto final_suspend() noexcept -> ::std::suspend_always { ::std::terminate(); }
-    [[noreturn]] auto unhandled_exception() noexcept -> void { ::std::terminate(); }
-    [[noreturn]] auto return_void() noexcept -> void { ::std::terminate(); }
-
-    auto unhandled_stopped() noexcept -> ::std::coroutine_handle<> {
-        ::beman::execution::set_stopped(::std::move(this->receiver));
-        return ::std::noop_coroutine();
-    }
-#line 43 "include/beman/execution/detail/operation_state_task.hpp"
-    auto get_env() const noexcept -> ::beman::execution::env_of_t<Receiver> {
-        return ::beman::execution::get_env(this->receiver);
-    }
-#line 47 "include/beman/execution/detail/operation_state_task.hpp"
-    auto get_return_object() noexcept -> ::beman::execution::detail::operation_state_task<Receiver>;
-
-  private:
-    Receiver& receiver;
-};
-
-#line 55 "include/beman/execution/detail/operation_state_task.hpp"
-template <typename Receiver>
-struct beman::execution::detail::operation_state_task {
-    using operation_state_concept = ::beman::execution::operation_state_t;
-    using promise_type            = ::beman::execution::detail::connect_awaitable_promise<Receiver>;
-
-    explicit operation_state_task(::std::coroutine_handle<> hndl) noexcept : handle(hndl) {}
-    operation_state_task(const operation_state_task&) = delete;
-    operation_state_task(operation_state_task&& other) noexcept : handle(::std::exchange(other.handle, {})) {}
-    ~operation_state_task() {
-        if (this->handle)
-            this->handle.destroy();
-    }
-    auto operator=(operation_state_task&&) -> operation_state_task&      = delete;
-    auto operator=(const operation_state_task&) -> operation_state_task& = delete;
-
-    auto start() & noexcept -> void { this->handle.resume(); }
-
-    ::std::coroutine_handle<> handle;
-};
-
-#line 77 "include/beman/execution/detail/operation_state_task.hpp"
-template <typename Receiver>
-auto beman::execution::detail::connect_awaitable_promise<Receiver>::get_return_object() noexcept
-    -> ::beman::execution::detail::operation_state_task<Receiver> {
-    return ::beman::execution::detail::operation_state_task<Receiver>(
-        std::coroutine_handle<connect_awaitable_promise>::from_promise(*this));
-}
-#line 18 "include/beman/execution/detail/sender.hpp"
-namespace beman::execution {
-export /* --------- */ struct sender_t {};
-} // namespace beman::execution
-namespace beman::execution::detail {
-template <typename Sender>
-concept is_sender = ::std::derived_from<typename Sender::sender_concept, ::beman::execution::sender_t>;
-
-template <typename Sender>
-concept enable_sender =
-    ::beman::execution::detail::is_sender<Sender> ||
-    ::beman::execution::detail::is_awaitable<Sender,
-                                             ::beman::execution::detail::env_promise<::beman::execution::env<>>>;
-} // namespace beman::execution::detail
-namespace beman::execution {
-export /* --------- */ template <typename Sender>
-concept sender = ::beman::execution::detail::enable_sender<::std::remove_cvref_t<Sender>> &&
-                 requires(const ::std::remove_cvref_t<Sender>& sndr) {
-                     { ::beman::execution::get_env(sndr) } -> ::beman::execution::detail::queryable;
-                 } && ::std::move_constructible<::std::remove_cvref_t<Sender>> &&
-                 ::std::constructible_from<::std::remove_cvref_t<Sender>, Sender>;
-} // namespace beman::execution
-
-#line 24 "include/beman/execution/detail/connect_awaitable.hpp"
-namespace beman::execution::detail {
-
-#line 30 "include/beman/execution/detail/connect_awaitable.hpp"
-template <typename T>
-struct awaiter_set_value {
-    using type = ::beman::execution::set_value_t(T);
-};
-
-#line 39 "include/beman/execution/detail/connect_awaitable.hpp"
-template <>
-struct awaiter_set_value<void> {
-    using type = ::beman::execution::set_value_t();
-};
-
-#line 49 "include/beman/execution/detail/connect_awaitable.hpp"
-template <typename Awaiter, typename Receiver>
-using awaiter_completion_signatures = ::beman::execution::completion_signatures<
-    typename ::beman::execution::detail::awaiter_set_value<::beman::execution::detail::await_result_type<
-        Awaiter,
-        ::beman::execution::detail::connect_awaitable_promise<Receiver>>>::type,
-    ::beman::execution::set_error_t(::std::exception_ptr),
-    ::beman::execution::set_stopped_t()>;
-
-#line 62 "include/beman/execution/detail/connect_awaitable.hpp"
-template <typename Awaiter, ::beman::execution::receiver Receiver>
-auto connect_awaitable(Awaiter awaiter, Receiver receiver)
-    -> ::beman::execution::detail::operation_state_task<Receiver>
-    requires ::beman::execution::
-        receiver_of<Receiver, ::beman::execution::detail::awaiter_completion_signatures<Awaiter, Receiver>>
-{
-
-#line 70 "include/beman/execution/detail/connect_awaitable.hpp"
-    using result_type =
-        ::beman::execution::detail::await_result_type<Awaiter,
-                                                      ::beman::execution::detail::connect_awaitable_promise<Receiver>>;
-
-    ::std::exception_ptr ep;
-    try {
-        if constexpr (std::same_as<void, result_type>) {
-            co_await ::std::move(awaiter);
-            co_await ::beman::execution::detail::suspend_complete(::beman::execution::set_value,
-                                                                  ::std::move(receiver));
-        } else {
-            co_await ::beman::execution::detail::suspend_complete(
-                ::beman::execution::set_value, ::std::move(receiver), co_await ::std::move(awaiter));
-        }
-    } catch (...) {
-        ep = ::std::current_exception();
-    }
-    co_await ::beman::execution::detail::suspend_complete(::beman::execution::set_error, ::std::move(receiver), ep);
-}
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/state_type.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Receiver>
-using state_type = ::std::decay_t<::beman::execution::detail::call_result_t<
-    decltype(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_state),
-    Sender,
-    Receiver&>>;
-}
-#line 15 "include/beman/execution/detail/schedule.hpp"
-namespace beman::execution {
-export /* --------- */ struct schedule_t {
-    template <typename Scheduler>
-        requires(not requires(Scheduler&& sched) {
-                    { ::std::forward<Scheduler>(sched).schedule() } -> ::beman::execution::sender;
-                })
-    auto operator()(Scheduler&& sched) const =
-        BEMAN_EXECUTION_DELETE("the scheduler needs a schedule() member returning a sender");
-
-    template <typename Scheduler>
-        requires requires(Scheduler&& sched) {
-            { ::std::forward<Scheduler>(sched).schedule() } -> ::beman::execution::sender;
-        }
-    auto operator()(Scheduler&& sched) const noexcept(noexcept(std::forward<Scheduler>(sched).schedule())) {
-        return std::forward<Scheduler>(sched).schedule();
-    }
-};
-
-export /* --------- */ inline constexpr ::beman::execution::schedule_t schedule{};
-} // namespace beman::execution
-
-#line 15 "include/beman/execution/detail/sender_adaptor_closure.hpp"
-namespace beman::execution::detail::pipeable {
-struct sender_adaptor_closure_base {};
-} // namespace beman::execution::detail::pipeable
-
-namespace beman::execution {
-// NOLINTBEGIN(bugprone-crtp-constructor-accessibility)
-export /* --------- */ template <typename>
-struct sender_adaptor_closure : ::beman::execution::detail::pipeable::sender_adaptor_closure_base {};
-// NOLINTEND(bugprone-crtp-constructor-accessibility)
-
-} // namespace beman::execution
-
-namespace beman::execution::detail {
-template <typename Closure>
-concept is_sender_adaptor_closure =
-    ::std::derived_from<::std::decay_t<Closure>, ::beman::execution::sender_adaptor_closure<::std::decay_t<Closure>>>;
-}
-#line 33 "include/beman/execution/detail/sender_adaptor_closure.hpp"
-namespace beman::execution::detail::pipeable {
-export /* --------- */ template <::beman::execution::sender Sender, typename Adaptor>
-    requires(!::beman::execution::sender<Adaptor>) &&
-            ::std::derived_from<::std::decay_t<Adaptor>,
-                                ::beman::execution::sender_adaptor_closure<::std::decay_t<Adaptor>>> &&
-            requires(Sender&& sender, Adaptor&& adaptor) {
-                { adaptor(::std::forward<Sender>(sender)) } -> ::beman::execution::sender;
-            }
-auto operator|(Sender&& sender, Adaptor&& adaptor) {
-    return adaptor(::std::forward<Sender>(sender));
-}
-} // namespace beman::execution::detail::pipeable
-
-#line 15 "include/beman/execution/detail/sender_for.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Tag>
-concept sender_for = ::beman::execution::sender<Sender> && ::std::same_as<::beman::execution::tag_of_t<Sender>, Tag>;
-}
-#line 14 "include/beman/execution/detail/sender_has_affine_on.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Env>
-concept sender_has_affine_on =
-    beman::execution::sender<::std::remove_cvref_t<Sender>> && requires(Sender&& sndr, const Env& env) {
-        sndr.template get<0>();
-        { sndr.template get<0>().affine_on(std::forward<Sender>(sndr), env) } -> ::beman::execution::sender;
-    };
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/default_domain.hpp"
-namespace beman::execution {
-
-#line 28 "include/beman/execution/detail/default_domain.hpp"
-export /* --------- */ struct default_domain {
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable... Env>
-        requires(sizeof...(Env) <= 1) && requires(Sender&& sender, Env&&... env) {
-            ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
-                                                                    ::std::forward<Env>(env)...);
-        }
-    static constexpr auto transform_sender(Sender&& sender, Env&&... env) noexcept(
-        noexcept(::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
-                                                                         ::std::forward<Env>(env)...)))
-        -> ::beman::execution::sender decltype(auto) {
-        return ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
-                                                                       ::std::forward<Env>(env)...);
-    }
-#line 42 "include/beman/execution/detail/default_domain.hpp"
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable... Env>
-        requires(sizeof...(Env) <= 1) && (not requires(Sender&& sender, Env&&... env) {
-                    ::beman::execution::tag_of_t<Sender>().transform_sender(::std::forward<Sender>(sender),
-                                                                            ::std::forward<Env>(env)...);
-                })
-    static constexpr auto transform_sender(Sender&& sender,
-                                           Env&&...) noexcept(noexcept(::std::forward<Sender>(sender)))
-        -> ::beman::execution::sender decltype(auto) {
-        return ::std::forward<Sender>(sender);
-    }
-#line 53 "include/beman/execution/detail/default_domain.hpp"
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
-        requires requires(Sender&& sender, Env&& env) {
-            ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
-                                                                 ::std::forward<Env>(env));
-        }
-    static constexpr auto transform_env(Sender&& sender, Env&& env) noexcept -> ::beman::execution::detail::queryable
-        decltype(auto) {
-        return ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
-                                                                    ::std::forward<Env>(env));
-    }
-#line 64 "include/beman/execution/detail/default_domain.hpp"
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
-        requires(not requires(Sender&& sender, Env&& env) {
-            ::beman::execution::tag_of_t<Sender>().transform_env(::std::forward<Sender>(sender),
-                                                                 ::std::forward<Env>(env));
-        })
-    static constexpr auto transform_env(Sender&&, Env&& env) noexcept -> ::beman::execution::detail::queryable
-        decltype(auto) {
-        return static_cast<Env>(::std::forward<Env>(env));
-    }
-#line 74 "include/beman/execution/detail/default_domain.hpp"
-    template <typename Tag, ::beman::execution::sender Sender, typename... Args>
-        requires requires(Sender&& sender, Args&&... args) {
-            Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-        }
-    static constexpr auto apply_sender(Tag, Sender&& sender, Args&&... args) noexcept(noexcept(
-        Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...))) -> decltype(auto) {
-        return Tag().apply_sender(::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-    }
-};
-} // namespace beman::execution
-
-#line 18 "include/beman/execution/detail/spawn_get_allocator.hpp"
-namespace beman::execution::detail {
-template <::beman::execution::sender Sndr, typename Ev>
-auto spawn_get_allocator(const Sndr& sndr, const Ev& ev) {
-    if constexpr (requires { ::beman::execution::get_allocator(ev); }) {
-        return ::std::pair(::beman::execution::get_allocator(ev), ev);
-    } else if constexpr (requires { ::beman::execution::get_allocator(::beman::execution::get_env(sndr)); }) {
-        auto alloc{::beman::execution::get_allocator(::beman::execution::get_env(sndr))};
-        return ::std::pair(alloc,
-                           ::beman::execution::detail::join_env(
-                               ::beman::execution::prop(::beman::execution::get_allocator, alloc), ev));
-    } else {
-        return ::std::pair(::std::allocator<void>{}, ev);
-    }
-}
-#line 33 "include/beman/execution/detail/spawn_get_allocator.hpp"
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/basic_state.hpp"
-namespace beman::execution::detail {
-
-#line 24 "include/beman/execution/detail/basic_state.hpp"
-export /* --------- */ template <typename Sender, typename Receiver>
-struct basic_state {
-    basic_state(Sender&& sender, Receiver&& rcvr) noexcept(true)
-        : receiver(::std::move(rcvr)),
-          state(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_state(
-              ::std::forward<Sender>(sender), this->receiver)) {}
-
-    Receiver                                                 receiver;
-    ::beman::execution::detail::state_type<Sender, Receiver> state;
-};
-template <typename Sender, typename Receiver>
-basic_state(Sender&&, Receiver&&) -> basic_state<Sender&&, Receiver>;
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/env_type.hpp"
-namespace beman::execution::detail {
-
-#line 22 "include/beman/execution/detail/env_type.hpp"
-template <typename Index, typename Sender, typename Receiver>
-using env_type = ::beman::execution::detail::call_result_t<
-    decltype(::beman::execution::detail::impls_for<::beman::execution::tag_of_t<Sender>>::get_env),
-    Index,
-    ::beman::execution::detail::state_type<Sender, Receiver>&,
-    const Receiver&>;
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/almost_scheduler.hpp"
-namespace beman::execution::detail {
-
-#line 24 "include/beman/execution/detail/almost_scheduler.hpp"
-template <typename Scheduler>
-concept almost_scheduler = ::std::derived_from<typename ::std::remove_cvref_t<Scheduler>::scheduler_concept,
-                                               ::beman::execution::scheduler_t> &&
-                           ::beman::execution::detail::queryable<Scheduler> &&
-                           requires(Scheduler&& sched) {
-                               {
-                                   ::beman::execution::schedule(::std::forward<Scheduler>(sched))
-                               } -> ::beman::execution::sender;
-                           } && ::std::equality_comparable<::std::remove_cvref_t<Scheduler>> &&
-                           ::std::copy_constructible<::std::remove_cvref_t<Scheduler>>;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/transform_sender.hpp"
-namespace beman::execution::detail {
-template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) &&
-            requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            } &&
-            (::std::same_as<::std::remove_cvref_t<Sender>,
-                            std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
-                                ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
-constexpr auto transform_sender(Domain, Sender&& sender, const Env&...) noexcept -> ::beman::execution::sender auto {
-    return ::std::forward<Sender>(sender);
-}
-#line 27 "include/beman/execution/detail/transform_sender.hpp"
-template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) &&
-            requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            } &&
-            (!::std::same_as<::std::remove_cvref_t<Sender>,
-                             std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
-                                 ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
-constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept -> ::beman::execution::sender
-    decltype(auto) {
-    return ::beman::execution::detail::transform_sender(
-        dom, dom.transform_sender(::std::forward<Sender>(sender), env...), env...);
-}
-#line 41 "include/beman/execution/detail/transform_sender.hpp"
-template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(not requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            }) && ::std::same_as<::std::remove_cvref_t<Sender>,
-                                 ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
-                                     ::std::declval<Sender>(), ::std::declval<Env>()...))>>
-constexpr auto
-    transform_sender(Domain, Sender&& sender, const Env&...) noexcept(noexcept(::std::forward<Sender>(sender)))
-        -> ::beman::execution::sender auto {
-    return sender;
-}
-#line 53 "include/beman/execution/detail/transform_sender.hpp"
-template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(not requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            }) &&
-            (!::std::same_as<::std::remove_cvref_t<Sender>,
-                             ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
-                                 ::std::declval<Sender>(), ::std::declval<Env>()...))>>)
-constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept(noexcept(
-    ::beman::execution::default_domain{}.transform_sender(::std::declval<Sender>(), ::std::declval<Env>()...)))
-    -> ::beman::execution::sender decltype(auto) {
-    return ::beman::execution::detail::transform_sender(
-        dom, ::beman::execution::default_domain{}.transform_sender(::std::forward<Sender>(sender), env...), env...);
-}
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) &&
-            requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            } &&
-            (::std::same_as<::std::remove_cvref_t<Sender>,
-                            std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
-                                ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
-constexpr auto transform_sender(Domain, Sender&& sender, const Env&...) noexcept -> ::beman::execution::sender
-    decltype(auto) {
-    return ::std::forward<Sender>(sender);
-}
-#line 82 "include/beman/execution/detail/transform_sender.hpp"
-export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) &&
-            requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            } &&
-            (!::std::same_as<::std::remove_cvref_t<Sender>,
-                             std::remove_cvref_t<decltype(::std::declval<Domain>().transform_sender(
-                                 ::std::declval<Sender>(), ::std::declval<const Env&>()...))>>)
-constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept -> ::beman::execution::sender
-    auto {
-    return ::beman::execution::detail::transform_sender(
-        dom, dom.transform_sender(::std::forward<Sender>(sender), env...), env...);
-}
-#line 96 "include/beman/execution/detail/transform_sender.hpp"
-export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) && (not requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            }) &&
-            ::std::same_as<::std::remove_cvref_t<Sender>,
-                           ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
-                               ::std::declval<Sender>(), ::std::declval<Env>()...))>>
-constexpr auto
-    transform_sender(Domain, Sender&& sender, const Env&...) noexcept(noexcept(::std::forward<Sender>(sender)))
-        -> ::beman::execution::sender decltype(auto) {
-    return ::std::forward<Sender>(sender);
-}
-#line 109 "include/beman/execution/detail/transform_sender.hpp"
-export /* --------- */ template <typename Domain, ::beman::execution::sender Sender, typename... Env>
-    requires(sizeof...(Env) < 2) && (not requires(Domain dom, Sender&& sender, const Env&... env) {
-                dom.transform_sender(::std::forward<Sender>(sender), env...);
-            }) &&
-            (!::std::same_as<::std::remove_cvref_t<Sender>,
-                             ::std::remove_cvref_t<decltype(::beman::execution::default_domain{}.transform_sender(
-                                 ::std::declval<Sender>(), ::std::declval<Env>()...))>>)
-constexpr auto transform_sender(Domain dom, Sender&& sender, const Env&... env) noexcept(
-    noexcept(::beman::execution::detail::transform_sender(
-        dom,
-        ::beman::execution::default_domain{}.transform_sender(::std::declval<Sender>(), ::std::declval<Env>()...),
-        env...))) -> ::beman::execution::sender decltype(auto) {
-    return ::beman::execution::detail::transform_sender(
-        dom, ::beman::execution::default_domain{}.transform_sender(::std::forward<Sender>(sender), env...), env...);
-}
-} // namespace beman::execution
-
-#line 18 "include/beman/execution/detail/sender_adaptor.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <typename Adaptor, typename... T>
-struct sender_adaptor : ::beman::execution::detail::product_type<::std::decay_t<Adaptor>, ::std::decay_t<T>...>,
-                        ::beman::execution::sender_adaptor_closure<sender_adaptor<Adaptor, T...>> {
-    template <::beman::execution::sender Sender, typename Self>
-    static auto apply(Sender&& sender, Self&& self) {
-        return [&self, &sender]<::std::size_t... I>(::std::index_sequence<I...>) {
-            auto&& fun(self.template get<0>());
-            return fun(::std::forward<Sender>(sender),
-                       ::beman::execution::detail::forward_like<Self>(self.template get<I + 1>())...);
-        }(::std::make_index_sequence<sender_adaptor::size() - 1u>{});
-    }
-    template <::beman::execution::sender Sender>
-    auto operator()(Sender&& sender) {
-        return apply(::std::forward<Sender>(sender), ::std::move(*this));
-    }
-    template <::beman::execution::sender Sender>
-    auto operator()(Sender&& sender) const {
-        return apply(::std::forward<Sender>(sender), *this);
-    }
-};
-template <typename... T>
-sender_adaptor(T&&...) -> sender_adaptor<T...>;
-} // namespace beman::execution::detail
-
-#line 16 "include/beman/execution/detail/sched_env.hpp"
-namespace beman::execution::detail {
-template <typename Scheduler>
-class sched_env {
-  private:
-    Scheduler sched;
-
-  public:
-    template <typename S>
-    explicit sched_env(S sch) : sched(::std::move(sch)) {}
-
-    auto query(const ::beman::execution::get_scheduler_t&) const noexcept { return this->sched; }
-    auto query(const ::beman::execution::get_domain_t& q) const noexcept {
-        if constexpr (requires { this->sched.query(q); })
-            return this->sched.query(q);
-        else
-            return ::beman::execution::default_domain{};
-    }
-};
-
-template <typename Scheduler>
-sched_env(Scheduler&&) -> sched_env<::std::remove_cvref_t<Scheduler>>;
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/apply_sender.hpp"
-namespace beman::execution {
-
-#line 19 "include/beman/execution/detail/apply_sender.hpp"
-export /* --------- */ template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
-    requires requires(Domain domain, Tag tag, Sender&& sender, Args&&... args) {
-        domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-    }
-constexpr auto apply_sender(Domain domain, Tag, Sender&& sender, Args&&... args) noexcept(noexcept(
-    domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...))) -> decltype(auto) {
-    return domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-}
-#line 32 "include/beman/execution/detail/apply_sender.hpp"
-export /* --------- */ template <typename Domain, typename Tag, ::beman::execution::sender Sender, typename... Args>
-    requires(not requires(Domain domain, Tag tag, Sender&& sender, Args&&... args) {
-                domain.apply_sender(Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-            }) && requires(Tag tag, Sender&& sender, Args&&... args) {
-        beman::execution::default_domain().apply_sender(
-            Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-    }
-constexpr auto apply_sender(Domain, Tag, Sender&& sender, Args&&... args) noexcept(
-    noexcept(beman::execution::default_domain().apply_sender(Tag(),
-                                                             ::std::forward<Sender>(sender),
-                                                             ::std::forward<Args>(args)...))) -> decltype(auto) {
-    return beman::execution::default_domain().apply_sender(
-        Tag(), ::std::forward<Sender>(sender), ::std::forward<Args>(args)...);
-}
-#line 47 "include/beman/execution/detail/apply_sender.hpp"
-} // namespace beman::execution
-
-#line 12 "include/beman/execution/detail/nested_sender_has_affine_on.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Env>
-concept nested_sender_has_affine_on = requires(Sender&& sndr, const Env& env) {
-    { sndr.template get<2>() } -> ::beman::execution::detail::sender_has_affine_on<Env>;
-};
-} // namespace beman::execution::detail
-
-#line 25 "include/beman/execution/detail/basic_receiver.hpp"
-namespace beman::execution::detail {
-
-#line 31 "include/beman/execution/detail/basic_receiver.hpp"
-template <typename Sender, typename Receiver, typename Index>
-    requires ::beman::execution::detail::
-        valid_specialization<::beman::execution::detail::env_type, Index, Sender, Receiver>
-    struct basic_receiver {
-    friend struct ::beman::execution::get_env_t;
-    friend struct ::beman::execution::set_error_t;
-    friend struct ::beman::execution::set_stopped_t;
-    friend struct ::beman::execution::set_value_t;
-
-    using receiver_concept                = ::beman::execution::receiver_t;
-    using tag_t                           = ::beman::execution::tag_of_t<Sender>;
-    using state_t                         = ::beman::execution::detail::state_type<Sender, Receiver>;
-    static constexpr const auto& complete = ::beman::execution::detail::impls_for<tag_t>::complete;
-    ::beman::execution::detail::basic_state<Sender, Receiver>* op{};
-
-  private:
-    template <typename... Args>
-    auto set_value(Args&&... args) && noexcept -> void
-        requires ::beman::execution::detail::
-            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_value_t, Args...>
-    {
-        this->complete(Index(),
-                       this->op->state,
-                       this->op->receiver,
-                       ::beman::execution::set_value_t(),
-                       ::std::forward<Args>(args)...);
-    }
-#line 59 "include/beman/execution/detail/basic_receiver.hpp"
-    template <typename Error>
-    auto set_error(Error&& error) && noexcept -> void
-        requires ::beman::execution::detail::
-            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_error_t, Error>
-    {
-        this->complete(Index(),
-                       this->op->state,
-                       this->op->receiver,
-                       ::beman::execution::set_error_t(),
-                       ::std::forward<Error>(error));
-    }
-#line 71 "include/beman/execution/detail/basic_receiver.hpp"
-    auto set_stopped() && noexcept -> void
-        requires ::beman::execution::detail::
-            callable<decltype(complete), Index, state_t&, Receiver&, ::beman::execution::set_stopped_t>
-    {
-        this->complete(Index(), this->op->state, this->op->receiver, ::beman::execution::set_stopped_t());
-    }
-#line 78 "include/beman/execution/detail/basic_receiver.hpp"
-    auto get_env() const noexcept -> ::beman::execution::detail::env_type<Index, Sender, Receiver> {
-        return ::beman::execution::detail::impls_for<tag_t>::get_env(Index(), this->op->state, this->op->receiver);
-    }
-};
-} // namespace beman::execution::detail
-
-#line 25 "include/beman/execution/detail/get_completion_scheduler.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Tag>
-struct get_completion_scheduler_t;
-
-template <typename Tag>
-struct get_completion_scheduler_t : ::beman::execution::forwarding_query_t {
-    template <typename Env>
-        requires(not requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                    env.query(self);
-                })
-    auto operator()(Env&&) const noexcept =
-        BEMAN_EXECUTION_DELETE("The environment needs a query(get_completion_scheduler_t) member");
-
-    template <typename Env>
-        requires(requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                    env.query(self);
-                } && (not requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                     { env.query(self) } noexcept;
-                 }))
-    auto operator()(Env&&) const noexcept =
-        BEMAN_EXECUTION_DELETE("The environment's query(get_completion_scheduler_t) has to be noexcept");
-
-    template <typename Env>
-        requires(
-                    requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                        env.query(self);
-                    } &&
-                    requires(const get_completion_scheduler_t& self, const ::std::remove_cvref_t<Env>& env) {
-                        { env.query(self) } noexcept;
-                    } &&
-                    (not requires(const get_completion_scheduler_t&                                  self,
-                                  const get_completion_scheduler_t<::beman::execution::set_value_t>& value_self,
-                                  const ::std::remove_cvref_t<Env>&                                  env) {
-                        { env.query(self) } noexcept -> ::beman::execution::detail::almost_scheduler;
-                        {
-                            ::beman::execution::get_env(::beman::execution::schedule(env.query(self)))
-                                .query(value_self)
-                        } -> ::beman::execution::detail::decayed_same_as<decltype(env.query(self))>;
-                    }))
-    auto operator()(Env&&) const noexcept =
-        BEMAN_EXECUTION_DELETE("The environment's query(get_completion_scheduler_t) has to return a scheduler");
-
-    template <typename Env>
-        requires requires(const get_completion_scheduler_t&                                  self,
-                          const get_completion_scheduler_t<::beman::execution::set_value_t>& value_self,
-                          const ::std::remove_cvref_t<Env>&                                  env) {
-            { env.query(self) } noexcept -> ::beman::execution::detail::almost_scheduler;
-            {
-                ::beman::execution::get_env(::beman::execution::schedule(env.query(self))).query(value_self)
-            } -> ::beman::execution::detail::decayed_same_as<decltype(env.query(self))>;
-        }
-    auto operator()(Env&& env) const noexcept {
-        return ::std::as_const(env).query(*this);
-    }
-};
-
-export /* --------- */ template <::beman::execution::detail::completion_tag Tag>
-inline constexpr get_completion_scheduler_t<Tag> get_completion_scheduler{};
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/scheduler.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Scheduler>
-concept scheduler = ::beman::execution::detail::almost_scheduler<Scheduler> && requires(Scheduler&& sched) {
-    {
-        ::beman::execution::get_completion_scheduler<::beman::execution::set_value_t>(
-            ::beman::execution::get_env(::beman::execution::schedule(::std::forward<Scheduler>(sched))))
-    } -> ::beman::execution::detail::decayed_same_as<Scheduler>;
-};
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/sched_attrs.hpp"
-namespace beman::execution::detail {
-
-template <typename Scheduler>
-class sched_attrs {
-  private:
-    Scheduler sched;
-
-  public:
-    template <typename S>
-        requires(!::std::same_as<sched_attrs, ::std::remove_cvref_t<S>>)
-    explicit sched_attrs(S&& s) : sched(::std::forward<S>(s)) {}
-
-    template <typename Tag>
-    auto query(const ::beman::execution::get_completion_scheduler_t<Tag>&) const noexcept {
-        return this->sched;
-    }
-#line 36 "include/beman/execution/detail/sched_attrs.hpp"
-    template <typename T = bool>
-        requires requires(Scheduler&& s) { s.query(::beman::execution::get_domain); }
-    auto query(const ::beman::execution::get_domain_t& q, T = true) const noexcept {
-        return this->sched.query(q);
-    }
-};
-
-template <typename Scheduler>
-sched_attrs(Scheduler&&) -> sched_attrs<::std::remove_cvref_t<Scheduler>>;
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/completion_domain.hpp"
-namespace beman::execution::detail {
-struct completion_domain_undefined {};
-template <typename, typename>
-struct completion_domain_merge {};
-template <typename T>
-struct completion_domain_merge<T, T> {
-    using type = T;
-};
-template <typename T>
-struct completion_domain_merge<completion_domain_undefined, T> {
-    using type = T;
-};
-template <typename T>
-struct completion_domain_merge<T, completion_domain_undefined> {
-    using type = T;
-};
-template <>
-struct completion_domain_merge<completion_domain_undefined, completion_domain_undefined> {
-    using type = completion_domain_undefined;
-};
-
-#line 43 "include/beman/execution/detail/completion_domain.hpp"
-template <typename Default = ::beman::execution::default_domain, typename Sender>
-constexpr auto completion_domain(const Sender& sender) noexcept {
-
-    static_assert(::beman::execution::sender<Sender>);
-    constexpr auto get = []<typename Tag>(Tag, const Sender& sender) {
-        if constexpr (requires {
-                          ::beman::execution::get_domain(
-                              ::beman::execution::get_completion_scheduler<Tag>(::beman::execution::get_env(sender)));
-                      }) {
-            return ::beman::execution::get_domain(
-                ::beman::execution::get_completion_scheduler<Tag>(::beman::execution::get_env(sender)));
-        } else {
-            return completion_domain_undefined{};
-        }
-    };
-
-    using type = typename completion_domain_merge<
-        typename completion_domain_merge<decltype(get(::beman::execution::set_error, sender)),
-                                         decltype(get(::beman::execution::set_stopped, sender))>::type,
-        decltype(get(::beman::execution::set_value, sender))>::type;
-    return ::std::conditional_t<::std::same_as<type, completion_domain_undefined>, Default, type>();
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/get_delegation_scheduler.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_delegation_scheduler_t {
-    template <typename Env>
-        requires requires(Env&& env, const get_delegation_scheduler_t& g) {
-            { ::std::as_const(env).query(g) } noexcept -> ::beman::execution::scheduler;
-        }
-    auto operator()(Env&& env) const noexcept {
-        return ::std::as_const(env).query(*this);
-    }
-    constexpr auto query(const ::beman::execution::forwarding_query_t&) const noexcept -> bool { return true; }
-};
-
-export /* --------- */ inline constexpr get_delegation_scheduler_t get_delegation_scheduler{};
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/get_domain_late.hpp"
-namespace beman::execution::detail {
-template <typename T>
-concept not_void = !::std::same_as<T, void>;
-
-template <typename Tag>
-struct get_domain_late_helper {
-    template <typename Sender, typename Env>
-    static constexpr auto get(const Sender& sender, const Env& env) noexcept {
-        if constexpr (requires {
-                          {
-                              ::beman::execution::get_domain(::beman::execution::get_env(sender))
-                          } -> ::beman::execution::detail::not_void;
-                      })
-            return ::beman::execution::get_domain(::beman::execution::get_env(sender));
-        else if constexpr (requires {
-                               {
-                                   ::beman::execution::detail::completion_domain<void>(sender)
-                               } -> ::beman::execution::detail::not_void;
-                           })
-            return ::beman::execution::detail::completion_domain<void>(sender);
-        else if constexpr (requires {
-                               { ::beman::execution::get_domain(env) } -> ::beman::execution::detail::not_void;
-                           })
-            return ::beman::execution::get_domain(env);
-        else if constexpr (requires {
-                               {
-                                   ::beman::execution::get_domain(::beman::execution::get_scheduler(env))
-                               } -> ::beman::execution::detail::not_void;
-                           })
-            return ::beman::execution::get_domain(::beman::execution::get_scheduler(env));
-        else
-            return ::beman::execution::default_domain();
-    }
-};
-template <typename Sender, typename Env>
-constexpr auto get_domain_late(const Sender& sender, const Env& env) noexcept {
-    using tag_t = ::beman::execution::tag_of_t<Sender>;
-    return ::beman::execution::detail::get_domain_late_helper<tag_t>::get(sender, env);
-}
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/get_domain_early.hpp"
-namespace beman::execution::detail {
-template <typename Sender>
-constexpr auto get_domain_early(const Sender& sender) noexcept {
-    if constexpr (requires { ::beman::execution::get_domain(::beman::execution::get_env(sender)); })
-        return decltype(::beman::execution::get_domain(::beman::execution::get_env(sender))){};
-    else if constexpr (requires { ::beman::execution::detail::completion_domain(sender); })
-        return decltype(::beman::execution::detail::completion_domain(sender)){};
-    else
-        return ::beman::execution::default_domain{};
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/schedule_result_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <::beman::execution::scheduler Scheduler>
-using schedule_result_t = decltype(::beman::execution::schedule(::std::declval<Scheduler>()));
-}
-#line 28 "include/beman/execution/detail/run_loop.hpp"
-namespace beman::execution {
-export /* --------- */ class run_loop {
-  private:
-    struct scheduler;
-
-    struct env {
-        run_loop* loop;
-
-        template <typename Completion>
-        auto query(const ::beman::execution::get_completion_scheduler_t<Completion>&) const noexcept -> scheduler {
-            return {this->loop};
-        }
-    };
-
-    struct opstate_base : ::beman::execution::detail::virtual_immovable {
-        opstate_base* next{};
-        virtual auto  execute() noexcept -> void = 0;
-    };
-
-    template <typename Receiver>
-    struct opstate : opstate_base {
-        using operation_state_concept = ::beman::execution::operation_state_t;
-
-        run_loop* loop;
-        Receiver  receiver;
-
-        // NOLINTBEGIN(misc-no-recursion)
-        template <typename R>
-        opstate(run_loop* l, R&& rcvr) : loop(l), receiver(::std::forward<Receiver>(rcvr)) {}
-        auto start() & noexcept -> void { this->loop->push_back(this); }
-        // NOLINTEND(misc-no-recursion)
-        auto execute() noexcept -> void override {
-            using token = decltype(::beman::execution::get_stop_token(::beman::execution::get_env(this->receiver)));
-            if constexpr (not ::beman::execution::unstoppable_token<token>) {
-                if (::beman::execution::get_stop_token(::beman::execution::get_env(this->receiver)).stop_requested())
-                    ::beman::execution::set_stopped(::std::move(this->receiver));
-                else
-                    ::beman::execution::set_value(::std::move(this->receiver));
-            } else
-                ::beman::execution::set_value(::std::move(this->receiver));
-        }
-    };
-    struct sender {
-        using sender_concept = ::beman::execution::sender_t;
-        template <typename Env = ::beman::execution::env<>>
-        auto get_completion_signatures(Env&& env) const noexcept {
-            if constexpr (::beman::execution::unstoppable_token<decltype(::beman::execution::get_stop_token(env))>)
-                return ::beman::execution::completion_signatures<::beman::execution::set_value_t()>{};
-            else
-                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(),
-                                                                 ::beman::execution::set_stopped_t()>{};
-        }
-#line 81 "include/beman/execution/detail/run_loop.hpp"
-        run_loop* loop;
-
-        auto get_env() const noexcept -> env { return {this->loop}; }
-        template <typename Receiver>
-        auto connect(Receiver&& receiver) noexcept -> opstate<::std::decay_t<Receiver>> {
-            return {this->loop, ::std::forward<Receiver>(receiver)};
-        }
-    };
-    struct scheduler {
-        using scheduler_concept = ::beman::execution::scheduler_t;
-
-        run_loop* loop;
-
-        auto schedule() noexcept -> sender { return {this->loop}; }
-        auto operator==(const scheduler&) const -> bool = default;
-    };
-
-    enum class state : unsigned char { starting, running, finishing };
-
-    state                     current_state{state::starting};
-    ::std::mutex              mutex{};
-    ::std::condition_variable condition{};
-    opstate_base*             front{};
-    opstate_base*             back{};
-
-    auto push_back(opstate_base* item) noexcept -> void {
-
-        ::std::lock_guard guard(this->mutex);
-        if (auto previous_back{::std::exchange(this->back, item)}) {
-            previous_back->next = item;
-        } else {
-            this->front = item;
-            this->condition.notify_one();
-        }
-    }
-    auto pop_front() noexcept -> opstate_base* {
-
-        ::std::unique_lock guard(this->mutex);
-        this->condition.wait(guard, [this] { return this->front || this->current_state == state::finishing; });
-        if (this->front == this->back)
-            this->back = nullptr;
-        return this->front ? ::std::exchange(this->front, this->front->next) : nullptr;
-    }
-#line 125 "include/beman/execution/detail/run_loop.hpp"
-  public:
-    run_loop() noexcept       = default;
-    run_loop(const run_loop&) = delete;
-    run_loop(run_loop&&)      = delete;
-    ~run_loop() {
-        ::std::lock_guard guard(this->mutex);
-        if (this->front != nullptr || this->current_state == state::running)
-            ::std::terminate();
-    }
-    auto operator=(const run_loop&) -> run_loop& = delete;
-    auto operator=(run_loop&&) -> run_loop&      = delete;
-
-    auto get_scheduler() -> scheduler { return {this}; }
-
-    auto run() -> void {
-        if (::std::lock_guard guard(this->mutex);
-            this->current_state != state::finishing &&
-            state::running == ::std::exchange(this->current_state, state::running)) {
-            ::std::terminate();
-        }
-#line 146 "include/beman/execution/detail/run_loop.hpp"
-        while (auto* op{this->pop_front()}) {
-            op->execute();
-        }
-    }
-    auto finish() -> void {
-        {
-            ::std::lock_guard guard(this->mutex);
-            this->current_state = state::finishing;
-        }
-        this->condition.notify_one();
-    }
-};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/get_completion_signatures.hpp"
-namespace beman::execution {
-export /* --------- */ struct get_completion_signatures_t {
-  private:
-    template <typename Sender, typename Env>
-    static auto get(Sender&& sender, Env&& env) noexcept {
-        auto new_sender{[](auto&& sndr, auto&& e) -> decltype(auto) {
-            auto domain{::beman::execution::detail::get_domain_late(sndr, e)};
-            return ::beman::execution::transform_sender(domain, ::std::forward<Sender>(sndr), ::std::forward<Env>(e));
-        }};
-
-        using sender_type = ::std::remove_cvref_t<decltype(new_sender(sender, env))>;
-        using decayed_env = ::std::remove_cvref_t<Env>;
-        if constexpr (requires { new_sender(sender, env).get_completion_signatures(env); })
-            return decltype(new_sender(sender, env).get_completion_signatures(env)){};
-        else if constexpr (requires { typename sender_type::completion_signatures; })
-            return typename sender_type::completion_signatures{};
-        else if constexpr (::beman::execution::detail::
-                               is_awaitable<sender_type, ::beman::execution::detail::env_promise<decayed_env>>) {
-            using result_type =
-                ::beman::execution::detail::await_result_type<sender_type,
-                                                              ::beman::execution::detail::env_promise<decayed_env>>;
-            if constexpr (::std::same_as<void, result_type>) {
-                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(),
-                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
-                                                                 ::beman::execution::set_stopped_t()>{};
-            } else {
-                return ::beman::execution::completion_signatures<::beman::execution::set_value_t(result_type),
-                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
-                                                                 ::beman::execution::set_stopped_t()>{};
-            }
-        }
-    }
-#line 55 "include/beman/execution/detail/get_completion_signatures.hpp"
-  public:
-    template <typename Sender, typename Env>
-        requires(!::std::same_as<void,
-                                 decltype(get_completion_signatures_t::get(::std::declval<Sender>(),
-                                                                           ::std::declval<Env>()))>)
-    auto operator()(Sender&& sender, Env&& env) const noexcept {
-        return this->get(::std::forward<Sender>(sender), ::std::forward<Env>(env));
-    }
-};
-export /* --------- */ inline constexpr get_completion_signatures_t get_completion_signatures{};
-} // namespace beman::execution
-
-#line 18 "include/beman/execution/detail/connect.hpp"
-namespace beman::execution::detail {
-
-#line 25 "include/beman/execution/detail/connect.hpp"
-export /* --------- */ struct connect_t {
-  private:
-    template <typename Sender, typename Receiver>
-    static auto make_new_sender(Sender&& sender, Receiver&& receiver)
-
-        noexcept(true) -> decltype(auto) {
-        return ::beman::execution::transform_sender(
-            decltype(::beman::execution::detail::get_domain_late(::std::forward<Sender>(sender),
-                                                                 ::beman::execution::get_env(receiver))){},
-            ::std::forward<Sender>(sender),
-            ::beman::execution::get_env(receiver));
-    }
-    template <typename Sender, typename Receiver>
-    static constexpr auto connect_noexcept() -> bool {
-        if constexpr (requires {
-                          make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>())
-                              .connect(::std::declval<Receiver>());
-                      }) {
-            return noexcept(make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>())
-                                .connect(::std::declval<Receiver>()));
-        } else if constexpr (requires {
-                                 ::beman::execution::detail::connect_awaitable(
-                                     make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>()),
-                                     ::std::declval<Receiver>());
-                             }) {
-            return noexcept(::beman::execution::detail::connect_awaitable(
-                make_new_sender(::std::declval<Sender>(), ::std::declval<Receiver>()), ::std::declval<Receiver>()));
-        }
-        return true;
-    }
-#line 56 "include/beman/execution/detail/connect.hpp"
-  public:
-    template <typename Sender, typename Receiver>
-    auto operator()(Sender&& sender, Receiver&& receiver) const noexcept(connect_noexcept<Sender, Receiver>()) {
-        auto new_sender = [&sender, &receiver]() -> decltype(auto) {
-            return make_new_sender(::std::forward<Sender>(sender), ::std::forward<Receiver>(receiver));
-        };
-
-        if constexpr (requires { new_sender().connect(::std::forward<Receiver>(receiver)); }) {
-            using state_type = decltype(new_sender().connect(::std::forward<Receiver>(receiver)));
-            static_assert(::beman::execution::operation_state<state_type>);
-            return new_sender().connect(::std::forward<Receiver>(receiver));
-        } else if constexpr (requires {
-                                 ::beman::execution::detail::connect_awaitable(new_sender(),
-                                                                               ::std::forward<Receiver>(receiver));
-                             }) {
-            return ::beman::execution::detail::connect_awaitable(new_sender(), ::std::forward<Receiver>(receiver));
-        } else {
-            enum bad_sender {};
-            static_assert(::std::same_as<bad_sender, decltype(new_sender())>,
-                          "result from transform_sender has no suitable connect()");
-        }
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-
-#line 86 "include/beman/execution/detail/connect.hpp"
-export /* --------- */ using connect_t = beman::execution::detail::connect_t;
-
-#line 95 "include/beman/execution/detail/connect.hpp"
-export /* --------- */ inline constexpr connect_t connect{};
-} // namespace beman::execution
-
-#line 16 "include/beman/execution/detail/sender_in.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
-concept sender_in =
-    ::beman::execution::sender<Sender> && ::beman::execution::detail::queryable<Env> &&
-    requires(Sender&& sender, Env&& env) {
-        {
-            ::beman::execution::get_completion_signatures(::std::forward<Sender>(sender), ::std::forward<Env>(env))
-        } -> ::beman::execution::detail::valid_completion_signatures;
-    };
-} // namespace beman::execution
-
-#line 13 "include/beman/execution/detail/connect_result_t.hpp"
-namespace beman::execution {
-
-#line 18 "include/beman/execution/detail/connect_result_t.hpp"
-export /* --------- */ template <typename Sender, typename Receiver>
-using connect_result_t = decltype(::beman::execution::connect(::std::declval<Sender>(), ::std::declval<Receiver>()));
-} // namespace beman::execution
-
-#line 29 "include/beman/execution/detail/stop_when.hpp"
-namespace beman::execution::detail {
-inline constexpr struct stop_when_t {
-    template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
-    struct sender;
-
-    template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
-    auto operator()(Sndr&& sndr, Tok&& tok) const noexcept;
-} stop_when{};
-} // namespace beman::execution::detail
-
-template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
-struct beman::execution::detail::stop_when_t::sender {
-    using sender_concept = ::beman::execution::sender_t;
-
-    stop_when_t               stop_when{};
-    std::remove_cvref_t<Tok>  tok;
-    std::remove_cvref_t<Sndr> sndr;
-
-    template <::beman::execution::receiver Rcvr>
-    struct state {
-        using operation_state_concept = ::beman::execution::operation_state_t;
-        using rcvr_t                  = ::std::remove_cvref_t<Rcvr>;
-        using token1_t                = ::std::remove_cvref_t<Tok>;
-        using token2_t =
-            decltype(::beman::execution::get_stop_token(::beman::execution::get_env(::std::declval<rcvr_t>())));
-
-        struct cb_t {
-            ::beman::execution::inplace_stop_source& source;
-            auto                                     operator()() const noexcept { this->source.request_stop(); }
-        };
-        struct base_state {
-            rcvr_t                                  rcvr;
-            ::beman::execution::inplace_stop_source source{};
-        };
-        struct env {
-            base_state* st;
-            auto        query(const ::beman::execution::get_stop_token_t&) const noexcept {
-                return this->st->source.get_token();
-            }
-            template <typename Q, typename... A>
-                requires requires(const Q& q, A&&... a, const rcvr_t& r) {
-                    q(::beman::execution::get_env(r), ::std::forward<A>(a)...);
-                }
-            auto query(const Q& q, A&&... a) const noexcept {
-                return q(::beman::execution::get_env(this->st->rcvr), ::std::forward<A>(a)...);
-            }
-        };
-
-        struct receiver {
-            using receiver_concept = ::beman::execution::receiver_t;
-            base_state* st;
-
-            auto get_env() const noexcept -> env { return env{this->st}; }
-            template <typename... A>
-            auto set_value(A&&... a) const noexcept -> void {
-                ::beman::execution::set_value(::std::move(this->st->rcvr), ::std::forward<A>(a)...);
-            }
-            template <typename E>
-            auto set_error(E&& e) const noexcept -> void {
-                ::beman::execution::set_error(::std::move(this->st->rcvr), ::std::forward<E>(e));
-            }
-            auto set_stopped() const noexcept -> void { ::beman::execution::set_stopped(::std::move(this->st->rcvr)); }
-        };
-        using inner_state_t =
-            decltype(::beman::execution::connect(::std::declval<Sndr>(), ::std::declval<receiver>()));
-
-        token1_t                                                               tok;
-        base_state                                                             base;
-        std::optional<::beman::execution::stop_callback_for_t<token1_t, cb_t>> cb1;
-        std::optional<::beman::execution::stop_callback_for_t<token2_t, cb_t>> cb2;
-        inner_state_t                                                          inner_state;
-
-        template <::beman::execution::sender S, ::beman::execution::stoppable_token T, ::beman::execution::receiver R>
-        state(S&& s, T&& t, R&& r)
-            : tok(::std::forward<T>(t)),
-              base{::std::forward<R>(r)},
-              inner_state(::beman::execution::connect(::std::forward<S>(s), receiver{&this->base})) {}
-
-        auto start() & noexcept {
-            this->cb1.emplace(this->tok, cb_t{this->base.source});
-            this->cb2.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(this->base.rcvr)),
-                              cb_t{this->base.source});
-            ::beman::execution::start(this->inner_state);
-        }
-    };
-
-    template <typename E>
-    auto get_completion_signatures(const E& e) const noexcept {
-        return ::beman::execution::get_completion_signatures(this->sndr, e);
-    }
-    template <::beman::execution::receiver Rcvr>
-    auto connect(Rcvr&& rcvr) && -> state<Rcvr> {
-        return state<Rcvr>{std::move(this->sndr), ::std::move(this->tok), ::std::forward<Rcvr>(rcvr)};
-    }
-};
-
-template <::beman::execution::sender Sndr, ::beman::execution::stoppable_token Tok>
-inline auto beman::execution::detail::stop_when_t::operator()(Sndr&& sndr, Tok&& tok) const noexcept {
-    if constexpr (::beman::execution::unstoppable_token<Tok>) {
-        return ::std::forward<Sndr>(sndr);
-    } else {
-        return sender<Sndr, Tok>{*this, ::std::forward<Tok>(tok), ::std::forward<Sndr>(sndr)};
-    }
-}
-#line 16 "include/beman/execution/detail/scope_token.hpp"
-namespace beman::execution::detail {
-struct token_test_env {};
-
-struct token_test_sender {
-    using sender_concept = ::beman::execution::sender_t;
-    template <typename... Env>
-    auto get_completion_signatures(const Env&...) const noexcept {
-        return ::beman::execution::completion_signatures<>{};
-    }
-};
-static_assert(::beman::execution::sender<::beman::execution::detail::token_test_sender>);
-static_assert(::beman::execution::sender_in<::beman::execution::detail::token_test_sender,
-                                            ::beman::execution::detail::token_test_env>);
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ template <typename Token>
-concept scope_token = ::std::copyable<Token> && requires(Token token) {
-    { token.try_associate() } -> ::std::same_as<bool>;
-    { token.disassociate() } noexcept;
-    {
-        token.wrap(::std::declval<::beman::execution::detail::token_test_sender>())
-    } -> ::beman::execution::sender_in<::beman::execution::detail::token_test_env>;
-};
-} // namespace beman::execution
-
-#line 16 "include/beman/execution/detail/completion_signatures_for.hpp"
-namespace beman::execution::detail {
-
-#line 22 "include/beman/execution/detail/completion_signatures_for.hpp"
-struct no_completion_signatures_defined_in_sender {};
-
-#line 29 "include/beman/execution/detail/completion_signatures_for.hpp"
-template <typename Sender, typename Env>
-struct completion_signatures_for_impl {
-    using type = ::beman::execution::detail::no_completion_signatures_defined_in_sender;
-};
-
-#line 39 "include/beman/execution/detail/completion_signatures_for.hpp"
-template <typename Sender, typename Env>
-using completion_signatures_for = ::std::conditional_t<
-    ::std::same_as<beman::execution::detail::no_completion_signatures_defined_in_sender,
-                   typename ::beman::execution::detail::completion_signatures_for_impl<Sender, Env>::type>,
-    typename ::beman::execution::detail::completion_signatures_for_impl<::std::remove_cvref_t<Sender>, Env>::type,
-    typename ::beman::execution::detail::completion_signatures_for_impl<Sender, Env>::type>;
-} // namespace beman::execution::detail
-
-#line 15 "include/beman/execution/detail/completion_signatures_of_t.hpp"
-namespace beman::execution {
-
-#line 20 "include/beman/execution/detail/completion_signatures_of_t.hpp"
-export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
-    requires ::beman::execution::sender_in<Sender, Env>
-using completion_signatures_of_t =
-    ::beman::execution::detail::call_result_t<::beman::execution::get_completion_signatures_t, Sender, Env>;
-} // namespace beman::execution
-
-#line 23 "include/beman/execution/detail/connect_all.hpp"
-namespace beman::execution::detail {
-
-#line 29 "include/beman/execution/detail/connect_all.hpp"
-struct connect_all_t {
-  private:
-    template <typename Fun, typename Tuple, ::std::size_t... I>
-    static auto apply_with_index_helper(::std::index_sequence<I...> seq, Fun&& fun, Tuple&& tuple) noexcept(noexcept(
-        ::std::forward<Fun>(fun)(seq, ::beman::execution::detail::forward_like<Tuple>(::std::get<I>(tuple))...)))
-        -> decltype(auto) {
-        return ::std::forward<Fun>(fun)(seq, ::beman::execution::detail::forward_like<Tuple>(::std::get<I>(tuple))...);
-    }
-    template <typename Fun, typename Tuple>
-    static auto apply_with_index(Fun&& fun, Tuple&& tuple) noexcept(
-        noexcept(apply_with_index_helper(::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>>>{},
-                                         ::std::forward<Fun>(fun),
-                                         ::std::forward<Tuple>(tuple)))) -> decltype(auto) {
-        return apply_with_index_helper(::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>>>{},
-                                       ::std::forward<Fun>(fun),
-                                       ::std::forward<Tuple>(tuple));
-    }
-#line 47 "include/beman/execution/detail/connect_all.hpp"
-    template <::std::size_t Start, typename Fun, typename Tuple, ::std::size_t... I>
-    static auto sub_apply_with_index_helper(::std::index_sequence<I...> seq, Fun&& fun, Tuple&& tuple) noexcept(
-        noexcept(::std::forward<Fun>(fun)(
-            seq, ::beman::execution::detail::forward_like<Tuple>(tuple.template get<I + Start>())...)))
-        -> decltype(auto) {
-        return ::std::forward<Fun>(fun)(
-            seq, ::beman::execution::detail::forward_like<Tuple>(tuple.template get<I + Start>())...);
-    }
-    template <::std::size_t Start, typename Fun, typename Tuple>
-        requires requires { ::std::declval<Tuple>().size(); }
-    static auto sub_apply_with_index(Fun&& fun, Tuple&& tuple) noexcept(noexcept(sub_apply_with_index_helper<Start>(
-        ::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>> - Start>{},
-        ::std::forward<Fun>(fun),
-        ::std::forward<Tuple>(tuple)))) -> decltype(auto) {
-        return sub_apply_with_index_helper<Start>(
-            ::std::make_index_sequence<::std::tuple_size_v<::std::decay_t<Tuple>> - Start>{},
-            ::std::forward<Fun>(fun),
-            ::std::forward<Tuple>(tuple));
-    }
-    template <::std::size_t Start, typename Fun, typename Tuple>
-        requires(not requires { ::std::declval<Tuple>().size(); })
-    static auto
-    sub_apply_with_index(Fun&& fun,
-                         Tuple&&) noexcept(noexcept(::std::forward<Fun>(fun)(::std::make_index_sequence<0u>{}))) {
-        return ::std::forward<Fun>(fun)(::std::make_index_sequence<0u>{});
-    }
-#line 74 "include/beman/execution/detail/connect_all.hpp"
-    template <typename Sender, typename Receiver>
-    struct connect_helper {
-        ::beman::execution::detail::basic_state<Sender, Receiver>* op;
-
-        template <::std::size_t... J, typename... C>
-        auto operator()(::std::index_sequence<J...>, C&&... c) noexcept(
-            (noexcept(::beman::execution::connect(
-                 ::beman::execution::detail::forward_like<Sender>(c),
-                 ::beman::execution::detail::
-                     basic_receiver<Sender, Receiver, ::std::integral_constant<::std::size_t, J>>{this->op})) &&
-             ... && true)) -> decltype(auto) {
-            return ::beman::execution::detail::product_type{::beman::execution::connect(
-                ::beman::execution::detail::forward_like<Sender>(c),
-                ::beman::execution::detail::
-                    basic_receiver<Sender, Receiver, ::std::integral_constant<::std::size_t, J>>{this->op})...};
-        }
-    };
-
-    static auto use(auto&&...) {}
-
-  public:
-#line 96 "include/beman/execution/detail/connect_all.hpp"
-    template <typename Sender, typename S, typename Receiver, ::std::size_t... I>
-        requires requires(Sender&& s) {
-            s.size();
-            s.template get<0>();
-        }
-    auto operator()(::beman::execution::detail::basic_state<Sender, Receiver>* op,
-                    S&&                                                        sender,
-                    ::std::index_sequence<I...>) const
-        noexcept(noexcept(sub_apply_with_index<2>(connect_helper<Sender, Receiver>{op}, ::std::forward<S>(sender))))
-            -> decltype(auto) {
-        return sub_apply_with_index<2>(connect_helper<Sender, Receiver>{op}, ::std::forward<S>(sender));
-    }
-    template <typename Sender, typename S, typename Receiver, ::std::size_t... I>
-    auto operator()(::beman::execution::detail::basic_state<Sender, Receiver>* op,
-                    S&&                                                        sender,
-                    ::std::index_sequence<I...>) const
-        noexcept(noexcept(apply_with_index(
-            connect_helper<Sender, Receiver>{op},
-            ::beman::execution::detail::get_sender_data(::std::forward<S>(sender)).children))) -> decltype(auto) {
-        return apply_with_index(connect_helper<Sender, Receiver>{op},
-                                ::beman::execution::detail::get_sender_data(::std::forward<S>(sender)).children);
-    }
-};
-
-#line 126 "include/beman/execution/detail/connect_all.hpp"
-export /* --------- */ constexpr connect_all_t connect_all{};
-} // namespace beman::execution::detail
-
-#line 18 "include/beman/execution/detail/error_types_of_t.hpp"
-namespace beman::execution {
-
-#line 23 "include/beman/execution/detail/error_types_of_t.hpp"
-export /* --------- */ template <typename Sender,
-                                 typename Env                         = ::beman::execution::env<>,
-                                 template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
-    requires ::beman::execution::sender_in<Sender, Env>
-using error_types_of_t =
-    ::beman::execution::detail::gather_signatures<::beman::execution::set_error_t,
-                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
-                                                  ::std::type_identity_t,
-                                                  Variant>;
-} // namespace beman::execution
-
-#line 18 "include/beman/execution/detail/sends_stopped.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Sender, typename Env = ::beman::execution::env<>>
-    requires ::beman::execution::sender_in<Sender, Env>
-inline constexpr bool sends_stopped{!::std::same_as<
-    ::beman::execution::detail::type_list<>,
-    ::beman::execution::detail::gather_signatures<::beman::execution::set_stopped_t,
-                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
-                                                  ::beman::execution::detail::type_list,
-                                                  ::beman::execution::detail::type_list>>};
-}
-#line 17 "include/beman/execution/detail/value_types_of_t.hpp"
-namespace beman::execution {
-export /* --------- */ template <typename Sender,
-                                 typename Env                         = ::beman::execution::env<>,
-                                 template <typename...> class Tuple   = ::beman::execution::detail::decayed_tuple,
-                                 template <typename...> class Variant = ::beman::execution::detail::variant_or_empty>
-    requires ::beman::execution::sender_in<Sender, Env>
-using value_types_of_t =
-    ::beman::execution::detail::gather_signatures<::beman::execution::set_value_t,
-                                                  ::beman::execution::completion_signatures_of_t<Sender, Env>,
-                                                  Tuple,
-                                                  Variant>;
-}
-#line 15 "include/beman/execution/detail/connect_all_result.hpp"
-namespace beman::execution::detail {
-
-#line 21 "include/beman/execution/detail/connect_all_result.hpp"
-template <typename Sender, typename Receiver>
-using connect_all_result =
-    ::beman::execution::detail::call_result_t<decltype(::beman::execution::detail::connect_all),
-                                              ::beman::execution::detail::basic_state<Sender, Receiver>*,
-                                              Sender,
-                                              ::beman::execution::detail::indices_for<Sender>>;
-} // namespace beman::execution::detail
-
-#line 28 "include/beman/execution/detail/sync_wait.hpp"
-namespace beman::execution::detail {
-export /* --------- */ struct sync_wait_env {
-    ::beman::execution::run_loop* loop{};
-
-    auto query(::beman::execution::get_scheduler_t) const noexcept { return this->loop->get_scheduler(); }
-    auto query(::beman::execution::get_delegation_scheduler_t) const noexcept { return this->loop->get_scheduler(); }
-};
-
-export /* --------- */ template <::beman::execution::sender_in<::beman::execution::detail::sync_wait_env> Sender>
-using sync_wait_result_type =
-    ::std::optional<::beman::execution::value_types_of_t<Sender,
-                                                         ::beman::execution::detail::sync_wait_env,
-                                                         ::beman::execution::detail::decayed_tuple,
-                                                         ::std::type_identity_t>>;
-
-export /* --------- */ template <typename Sender>
-struct sync_wait_state {
-    ::beman::execution::run_loop loop{};
-    ::std::exception_ptr         error{};
-
-    ::beman::execution::detail::sync_wait_result_type<Sender> result{};
-};
-
-export /* --------- */ template <typename Sender>
-struct sync_wait_receiver {
-    using receiver_concept = ::beman::execution::receiver_t;
-
-    ::beman::execution::detail::sync_wait_state<Sender>* state{};
-
-    template <typename Error>
-    auto set_error(Error&& error) && noexcept -> void {
-        this->state->error = ::beman::execution::detail::as_except_ptr(::std::forward<Error>(error));
-        this->state->loop.finish();
-    }
-    auto set_stopped() && noexcept -> void { this->state->loop.finish(); }
-    template <typename... Args>
-    auto set_value(Args&&... args) && noexcept -> void {
-        try {
-            this->state->result.emplace(::std::forward<Args>(args)...);
-        } catch (...) {
-            this->state->error = ::std::current_exception();
-        }
-        this->state->loop.finish();
-    }
-#line 74 "include/beman/execution/detail/sync_wait.hpp"
-    auto get_env() const noexcept -> ::beman::execution::detail::sync_wait_env {
-        return ::beman::execution::detail::sync_wait_env{&this->state->loop};
-    }
-};
-
-struct sync_wait_t {
-    template <typename Sender>
-    auto apply_sender(Sender&& sender) const {
-        ::beman::execution::detail::sync_wait_state<Sender> state;
-        auto op{::beman::execution::connect(::std::forward<Sender>(sender),
-                                            ::beman::execution::detail::sync_wait_receiver<Sender>{&state})};
-        ::beman::execution::start(op);
-
-        state.loop.run();
-        if (state.error) {
-            ::std::rethrow_exception(state.error);
-        }
-        return ::std::move(state.result);
-    }
-#line 94 "include/beman/execution/detail/sync_wait.hpp"
-    template <::beman::execution::sender_in<::beman::execution::detail::sync_wait_env> Sender>
-        requires requires(Sender&& sender, const sync_wait_t& self) {
-            typename ::beman::execution::detail::sync_wait_result_type<Sender>;
-            {
-                ::beman::execution::apply_sender(
-                    ::beman::execution::detail::get_domain_early(std::forward<Sender>(sender)),
-                    self,
-                    ::std::forward<Sender>(sender))
-            } -> ::std::same_as<::beman::execution::detail::sync_wait_result_type<Sender>>;
-        }
-    auto operator()(Sender&& sender) const {
-        auto domain{::beman::execution::detail::get_domain_early(sender)};
-        return ::beman::execution::apply_sender(domain, *this, ::std::forward<Sender>(sender));
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using sync_wait_t = ::beman::execution::detail::sync_wait_t;
-
-#line 160 "include/beman/execution/detail/sync_wait.hpp"
-export /* --------- */ inline constexpr ::beman::execution::sync_wait_t sync_wait{};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/basic_operation.hpp"
-namespace beman::execution::detail {
-
-#line 29 "include/beman/execution/detail/basic_operation.hpp"
-export /* --------- */ template <typename Sender, typename Receiver>
-    requires ::beman::execution::detail::
-
-        valid_specialization<::beman::execution::detail::state_type, std::remove_cvref_t<Sender>, Receiver>
-    struct basic_operation : ::beman::execution::detail::basic_state<Sender, Receiver> {
-
-    friend struct ::beman::execution::start_t;
-    using operation_state_concept = ::beman::execution::operation_state_t;
-    using tag_t                   = ::beman::execution::tag_of_t<Sender>;
-
-    using inner_ops_t = ::beman::execution::detail::connect_all_result<Sender, Receiver>;
-    inner_ops_t inner_ops;
-
-    basic_operation(Sender&& sender, Receiver&& rcvr) noexcept(
-        noexcept(::beman::execution::detail::basic_state<Sender, Receiver>(::std::forward<Sender>(sender),
-                                                                           ::std::move(rcvr))) &&
-        noexcept(::beman::execution::detail::connect_all(this,
-                                                         ::std::forward<Sender>(sender),
-                                                         ::beman::execution::detail::indices_for<Sender>())))
-        : ::beman::execution::detail::basic_state<Sender, Receiver>(::std::forward<Sender>(sender), ::std::move(rcvr)),
-          // NOLINTBEGIN(bugprone-use-after-move,hicpp-invalid-access-moved)
-
-          inner_ops(::beman::execution::detail::connect_all(
-              this, ::std::forward<Sender>(sender), ::beman::execution::detail::indices_for<Sender>())) {}
-    // NOLINTEND(bugprone-use-after-move,hicpp-invalid-access-moved)
-
-  private:
-    auto start() & noexcept -> void {
-        ::std::invoke(
-            [this]<::std::size_t... I>(::std::index_sequence<I...>) {
-                ::beman::execution::detail::impls_for<tag_t>::start(
-                    this->state, this->receiver, this->inner_ops.template get<I>()...);
-            },
-            ::std::make_index_sequence<inner_ops_t::size()>{});
-    }
-};
-template <typename Sender, typename Receiver>
-basic_operation(Sender&&, Receiver&&) -> basic_operation<Sender&&, Receiver>;
-} // namespace beman::execution::detail
-
-#line 17 "include/beman/execution/detail/single_sender_value_type.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Env>
-struct single_sender_value_type_helper;
-
-template <typename Sender, typename Env>
-    requires requires {
-        typename ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
-    }
-struct single_sender_value_type_helper<Sender, Env> {
-    using type = ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
-};
-
-template <typename Sender, typename Env>
-    requires ::std::same_as<::std::variant<::std::tuple<>>,
-                            ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>> ||
-             ::std::same_as<::std::variant<>,
-                            ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>>
-struct single_sender_value_type_helper<Sender, Env> {
-    using type = void;
-};
-
-template <typename Sender, typename Env>
-    requires(not requires {
-                typename ::beman::execution::value_types_of_t<Sender, Env, ::std::decay_t, ::std::type_identity_t>;
-            }) &&
-            (!::std::same_as<::std::variant<::std::tuple<>>,
-                             ::beman::execution::value_types_of_t<Sender, Env, ::std::tuple, ::std::variant>>) &&
-            requires {
-                typename ::beman::execution::
-                    value_types_of_t<Sender, Env, ::beman::execution::detail::decayed_tuple, ::std::type_identity_t>;
-            }
-struct single_sender_value_type_helper<Sender, Env> {
-    using type = ::beman::execution::
-        value_types_of_t<Sender, Env, ::beman::execution::detail::decayed_tuple, ::std::type_identity_t>;
-};
-
-template <typename Sender, typename Env>
-using single_sender_value_type = typename single_sender_value_type_helper<Sender, Env>::type;
-} // namespace beman::execution::detail
-
-#line 23 "include/beman/execution/detail/basic_sender.hpp"
-namespace beman::execution::detail {
-
-#line 29 "include/beman/execution/detail/basic_sender.hpp"
-template <typename Tag, typename Data, typename... Child>
-struct basic_sender : ::beman::execution::detail::product_type<Tag, Data, Child...> {
-    friend struct ::beman::execution::detail::connect_t;
-    friend struct ::beman::execution::get_completion_signatures_t;
-    using sender_concept = ::beman::execution::sender_t;
-    using indices_for    = ::std::index_sequence_for<Child...>;
-
-    auto get_env() const noexcept -> decltype(auto) {
-        auto&& d{this->template get<1>()};
-        return sub_apply<2>(
-            [&d](auto&&... c) { return ::beman::execution::detail::impls_for<Tag>::get_attrs(d, c...); }, *this);
-    }
-#line 42 "include/beman/execution/detail/basic_sender.hpp"
-    template <typename Receiver>
-        requires(!::beman::execution::receiver<Receiver>)
-    auto connect(Receiver receiver) = BEMAN_EXECUTION_DELETE("the passed receiver doesn't model receiver");
-
-  private:
-#if __cpp_explicit_this_parameter < 302110L
-    template <::beman::execution::receiver Receiver>
-    auto connect(Receiver receiver) & noexcept(
-        noexcept(::beman::execution::detail::basic_operation<basic_sender&, Receiver>{*this, ::std::move(receiver)}))
-        -> ::beman::execution::detail::basic_operation<basic_sender&, Receiver> {
-        return {*this, ::std::move(receiver)};
-    }
-    template <::beman::execution::receiver Receiver>
-    auto connect(Receiver receiver) const& noexcept(noexcept(
-        ::beman::execution::detail::basic_operation<const basic_sender&, Receiver>{*this, ::std::move(receiver)}))
-        -> ::beman::execution::detail::basic_operation<const basic_sender&, Receiver> {
-        return {*this, ::std::move(receiver)};
-    }
-    template <::beman::execution::receiver Receiver>
-    auto connect(Receiver receiver) && noexcept(
-        noexcept(::beman::execution::detail::basic_operation<basic_sender, Receiver>{::std::move(*this),
-                                                                                     ::std::move(receiver)}))
-        -> ::beman::execution::detail::basic_operation<basic_sender, Receiver> {
-        return {::std::move(*this), ::std::move(receiver)};
-    }
-#else
-    template <::beman::execution::detail::decays_to<basic_sender> Self, ::beman::execution::receiver Receiver>
-    auto
-    connect(this Self&& self,
-            Receiver receiver) noexcept(noexcept(::beman::execution::detail::basic_operation<basic_sender, Receiver>{
-        ::std::forward<Self>(self), ::std::move(receiver)}))
-        -> ::beman::execution::detail::basic_operation<Self, Receiver> {
-        return {::std::forward<Self>(self), ::std::move(receiver)};
-    }
-#endif
-#if __cpp_explicit_this_parameter < 302110L
-    template <typename Env>
-    auto
-    get_completion_signatures(Env&&) && -> ::beman::execution::detail::completion_signatures_for<basic_sender, Env> {
-        return {};
-    }
-    template <typename Env>
-    auto get_completion_signatures(
-        Env&&) const&& -> ::beman::execution::detail::completion_signatures_for<const basic_sender, Env> {
-        return {};
-    }
-    template <typename Env>
-    auto
-    get_completion_signatures(Env&&) & -> ::beman::execution::detail::completion_signatures_for<basic_sender, Env> {
-        return {};
-    }
-    template <typename Env>
-    auto get_completion_signatures(
-        Env&&) const& -> ::beman::execution::detail::completion_signatures_for<const basic_sender, Env> {
-        return {};
-    }
-#else
-    template <::beman::execution::detail::decays_to<basic_sender> Self, typename Env>
-    auto get_completion_signatures(this Self&&, Env&&) noexcept
-        -> ::beman::execution::detail::completion_signatures_for<Self, Env> {
-        return {};
-    }
-#endif
-};
-} // namespace beman::execution::detail
-
-#line 13 "include/beman/execution/detail/single_sender.hpp"
-namespace beman::execution::detail {
-template <typename Sender, typename Env>
-concept single_sender = ::beman::execution::sender_in<Sender, Env> &&
-                        requires { typename ::beman::execution::detail::single_sender_value_type<Sender, Env>; };
-} // namespace beman::execution::detail
-
-#line 18 "include/beman/execution/detail/make_sender.hpp"
-namespace beman::execution::detail {
-struct make_sender_empty {};
-
-template <typename Tag, typename Data = ::beman::execution::detail::make_sender_empty, typename... Child>
-    requires ::std::semiregular<Tag> && ::beman::execution::detail::movable_value<Data> &&
-             (::beman::execution::sender<Child> && ...)
-constexpr auto make_sender(Tag tag, Data&& data, Child&&... child) {
-    return ::beman::execution::detail::basic_sender<Tag, ::std::decay_t<Data>, ::std::decay_t<Child>...>{
-        tag, ::std::forward<Data>(data), ::std::forward<Child>(child)...};
-}
-} // namespace beman::execution::detail
-
-#line 14 "include/beman/execution/detail/awaitable_sender.hpp"
-namespace beman::execution::detail {
-template <class Sndr, class Promise>
-concept awaitable_sender =
-    ::beman::execution::detail::single_sender<Sndr, ::beman::execution::env_of_t<Promise>> && requires(Promise& prom) {
-        { prom.unhandled_stopped() } -> ::std::convertible_to<::std::coroutine_handle<>>;
-    };
-} // namespace beman::execution::detail
-
-#line 29 "include/beman/execution/detail/sender_awaitable.hpp"
-namespace beman::execution::detail {
-template <class Sndr, class Promise>
-class sender_awaitable {
-    struct unit {};
-    using value_type =
-        ::beman::execution::detail::single_sender_value_type<Sndr, ::beman::execution::env_of_t<Promise>>;
-    using result_type  = ::std::conditional_t<::std::is_void_v<value_type>, unit, value_type>;
-    using variant_type = ::std::variant<::std::monostate, result_type, ::std::exception_ptr>;
-    using data_type    = ::std::tuple<variant_type, ::std::atomic<bool>, ::std::coroutine_handle<Promise>>;
-
-    struct awaitable_receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-
-        void resume() {
-            if (::std::get<1>(*result_ptr_).exchange(true, std::memory_order_acq_rel)) {
-                ::std::get<2>(*result_ptr_).resume();
-            }
-        }
-#line 48 "include/beman/execution/detail/sender_awaitable.hpp"
-        template <class... Args>
-            requires ::std::constructible_from<result_type, Args...>
-        void set_value(Args&&... args) && noexcept {
-            try {
-                ::std::get<0>(*result_ptr_).template emplace<1>(::std::forward<Args>(args)...);
-            } catch (...) {
-                ::std::get<0>(*result_ptr_).template emplace<2>(::std::current_exception());
-            }
-            this->resume();
-        }
-        template <class Error>
-        void set_error(Error&& error) && noexcept {
-            ::std::get<0>(*result_ptr_)
-                .template emplace<2>(::beman::execution::detail::as_except_ptr(::std::forward<Error>(error)));
-            this->resume();
-        }
-#line 65 "include/beman/execution/detail/sender_awaitable.hpp"
-        void set_stopped() && noexcept {
-            if (::std::get<1>(*result_ptr_).exchange(true, ::std::memory_order_acq_rel)) {
-                static_cast<::std::coroutine_handle<>>(::std::get<2>(*result_ptr_).promise().unhandled_stopped())
-                    .resume();
-            }
-        }
-#line 72 "include/beman/execution/detail/sender_awaitable.hpp"
-        auto get_env() const noexcept {
-            return ::beman::execution::detail::fwd_env{
-                ::beman::execution::get_env(::std::get<2>(*result_ptr_).promise())};
-        }
-#line 77 "include/beman/execution/detail/sender_awaitable.hpp"
-        data_type* result_ptr_;
-    };
-    using op_state_type = ::beman::execution::connect_result_t<Sndr, awaitable_receiver>;
-
-    data_type     result{};
-    op_state_type state;
-
-  public:
-    sender_awaitable(Sndr&& sndr, Promise& p)
-        : result{::std::monostate{}, false, ::std::coroutine_handle<Promise>::from_promise(p)},
-          state{::beman::execution::connect(::std::forward<Sndr>(sndr),
-                                            sender_awaitable::awaitable_receiver{::std::addressof(result)})} {}
-
-    static constexpr bool     await_ready() noexcept { return false; }
-    ::std::coroutine_handle<> await_suspend(::std::coroutine_handle<Promise> handle) noexcept {
-        ::beman::execution::start(state);
-        if (::std::get<1>(this->result).exchange(true, std::memory_order_acq_rel)) {
-            if (::std::holds_alternative<::std::monostate>(::std::get<0>(this->result))) {
-                return ::std::get<2>(this->result).promise().unhandled_stopped();
-            }
-            return ::std::move(handle);
-        }
-        return ::std::noop_coroutine();
-    }
-    value_type await_resume() {
-        if (::std::holds_alternative<::std::exception_ptr>(::std::get<0>(result))) {
-            ::std::rethrow_exception(::std::get<::std::exception_ptr>(::std::get<0>(result)));
-        }
-        if constexpr (::std::is_void_v<value_type>) {
-            return;
-        } else {
-            return ::std::get<value_type>(std::move(::std::get<0>(result)));
-        }
-    }
-};
-} // namespace beman::execution::detail
-
-#line 33 "include/beman/execution/detail/bulk.hpp"
-namespace beman::execution::detail {
-
-struct bulk_t : ::beman::execution::sender_adaptor_closure<bulk_t> {
-
-    template <class Shape, class f>
-        requires(std::is_integral_v<Shape> && ::beman::execution::detail::movable_value<f>)
-    auto operator()(Shape&& shape, f&& fun) const {
-        return beman::execution::detail::sender_adaptor{*this, std::forward<Shape>(shape), std::forward<f>(fun)};
-    }
-#line 43 "include/beman/execution/detail/bulk.hpp"
-    template <class Sender, class Shape, class f>
-        requires(::beman::execution::sender<Sender> && std::is_integral_v<Shape> &&
-                 ::beman::execution::detail::movable_value<f>)
-    auto operator()(Sender&& sndr, Shape&& shape, f&& fun) const {
-
-        auto domain{::beman::execution::detail::get_domain_early(sndr)};
-
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this, ::beman::execution::detail::product_type<Shape, f>{shape, fun}, std::forward<Sender>(sndr)));
-    }
-};
-
-template <>
-struct impls_for<bulk_t> : ::beman::execution::detail::default_impls {
-
-    static constexpr auto complete = []<class Index, class Shape, class Fun, class Rcvr, class Tag, class... Args>(
-                                         Index,
-                                         ::beman::execution::detail::product_type<Shape, Fun>& state,
-                                         Rcvr&                                                 rcvr,
-                                         Tag,
-                                         Args&&... args) noexcept -> void
-        requires(!::std::same_as<Tag, set_value_t> || std::is_invocable_v<Fun, Shape, Args...>)
-    {
-        if constexpr (std::same_as<Tag, set_value_t>) {
-            auto& [shape, f] = state;
-
-            using s_type = std::remove_cvref_t<decltype(shape)>;
-
-            constexpr bool nothrow = noexcept(f(s_type(shape), args...));
-
-            try {
-                [&]() noexcept(nothrow) {
-                    for (decltype(s_type(shape)) i = 0; i < shape; i++) {
-                        f(s_type(i), args...);
-                    }
-                    Tag()(std::move(rcvr), std::forward<Args>(args)...);
-                }();
-
-            } catch (...) {
-                if constexpr (not nothrow) {
-                    ::beman::execution::set_error(std::move(rcvr), std::current_exception());
-                }
-            }
-        } else {
-            Tag()(std::move(rcvr), std::forward<Args>(args)...);
-        }
-    };
-};
-
-template <typename, typename, typename>
-struct fixed_completions_helper;
-
-template <typename F, typename Shape, typename... Args>
-struct fixed_completions_helper<F, Shape, completion_signatures<Args...>> {
-
-    template <typename, typename>
-    struct may_throw;
-    template <typename XF, typename Tag, typename... XArgs>
-    struct may_throw<XF, Tag(XArgs...)> {
-        static constexpr bool value =
-            std::same_as<Tag, ::beman::execution::set_value_t> && !::std::is_nothrow_invocable<XF, Shape, XArgs...>();
-    };
-    template <typename XF, typename... Sigs>
-    struct may_throw<XF, completion_signatures<Sigs...>> {
-        static constexpr bool value = (false || ... || may_throw<XF, Sigs>::value);
-    };
-
-    using type = std::conditional_t<!may_throw<F, Args...>::value,
-                                    completion_signatures<Args...>,
-                                    completion_signatures<Args..., set_error_t(std::exception_ptr)>>;
-};
-
-template <typename F, typename Shape, typename Completions>
-using fixed_completions = typename fixed_completions_helper<F, Shape, Completions>::type;
-
-template <class Shape, class F, class Sender, class Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::
-        basic_sender<::beman::execution::detail::bulk_t, ::beman::execution::detail::product_type<Shape, F>, Sender>,
-    Env> {
-
-    using completions = decltype(get_completion_signatures(std::declval<Sender>(), std::declval<Env>()));
-    using type        = ::beman::execution::detail::meta::unique<
-               ::beman::execution::detail::meta::combine<fixed_completions<F, Shape, completions>>>;
-};
-
-} // namespace beman::execution::detail
-
-#line 135 "include/beman/execution/detail/bulk.hpp"
-namespace beman::execution {
-
-export /* --------- */ using bulk_t = ::beman::execution::detail::bulk_t;
-export /* --------- */ inline constexpr ::beman::execution::bulk_t bulk{};
-
-} // namespace beman::execution
-
-#line 32 "include/beman/execution/detail/into_variant.hpp"
-namespace beman::execution::detail {
-export /* --------- */ struct into_variant_t {
-    template <::beman::execution::sender Sender>
-    auto operator()(Sender&& sender) const {
-        auto domain{::beman::execution::detail::get_domain_early(sender)};
-        (void)domain;
-        return ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender));
-
-#line 43 "include/beman/execution/detail/into_variant.hpp"
-    }
-};
-
-template <>
-struct impls_for<::beman::execution::detail::into_variant_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_state = []<typename Sender, typename Receiver>(Sender&&, Receiver&&) noexcept
-        -> ::std::type_identity<::beman::execution::value_types_of_t<::beman::execution::detail::child_type<Sender>,
-                                                                     ::beman::execution::env_of_t<Receiver>>> {
-        return {};
-    };
-    static constexpr auto complete = []<typename State, typename Tag, typename... Args>(
-                                         auto, State, auto& receiver, Tag, Args&&... args) noexcept -> void {
-        if constexpr (::std::same_as<Tag, ::beman::execution::set_value_t>) {
-            using variant_type = typename State::type;
-            using tuple_type   = ::beman::execution::detail::decayed_tuple<Args...>;
-            try {
-                if constexpr (sizeof...(Args) == 0u)
-                    ::beman::execution::set_value(::std::move(receiver));
-                else
-                    ::beman::execution::set_value(::std::move(receiver),
-                                                  variant_type(tuple_type{::std::forward<Args>(args)...}));
-            } catch (...) {
-                ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-            }
-#line 68 "include/beman/execution/detail/into_variant.hpp"
-        } else {
-            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
-        }
-    };
-};
-
-template <typename Sender, typename State, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::into_variant_t, State, Sender>,
-    Env> {
-    using variant_type = ::beman::execution::value_types_of_t<Sender, Env>;
-    using value_types =
-        ::std::conditional_t<::std::same_as<variant_type, ::beman::execution::detail::empty_variant>,
-                             ::beman::execution::completion_signatures<>,
-                             ::beman::execution::completion_signatures<::beman::execution::set_value_t(variant_type)>>;
-    template <typename... E>
-    using make_error_types = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
-
-    using error_types = ::beman::execution::error_types_of_t<Sender, Env, make_error_types>;
-    using stopped_types =
-        ::std::conditional_t<::beman::execution::sends_stopped<Sender, Env>,
-                             ::beman::execution::completion_signatures<::beman::execution::set_stopped_t()>,
-                             ::beman::execution::completion_signatures<>>;
-    using type = ::beman::execution::detail::meta::
-        combine<value_types, ::beman::execution::detail::meta::combine<error_types, stopped_types>>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using into_variant_t = ::beman::execution::detail::into_variant_t;
-export /* --------- */ inline constexpr into_variant_t into_variant{};
-} // namespace beman::execution
-
-#line 25 "include/beman/execution/detail/just.hpp"
-namespace beman::execution::detail {
-template <typename Completion, typename... T>
-concept just_size = (!::std::same_as<Completion, ::beman::execution::set_error_t> or 1u == sizeof...(T)) &&
-                    (!::std::same_as<Completion, ::beman::execution::set_stopped_t> or 0u == sizeof...(T));
-template <typename Completion>
-struct just_t {
-    template <typename... T>
-        requires ::beman::execution::detail::just_size<Completion, T...> &&
-                 (::beman::execution::detail::movable_value<T> && ...)
-    auto operator()(T&&... arg) const {
-        return ::beman::execution::detail::make_sender(
-            *this, ::beman::execution::detail::product_type{::std::forward<T>(arg)...});
-    }
-    template <::beman::execution::sender Sender>
-    static auto affine_on(Sender&& sndr, const auto&) noexcept {
-        return ::std::forward<Sender>(sndr);
-    }
-};
-
-template <typename Completion, typename... T, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<just_t<Completion>, ::beman::execution::detail::product_type<T...>>,
-    Env> {
-    using type = ::beman::execution::completion_signatures<Completion(T...)>;
-};
-
-template <typename Completion>
-struct impls_for<just_t<Completion>> : ::beman::execution::detail::default_impls {
-    static constexpr auto start = []<typename State>(State& state, auto& receiver) noexcept -> void {
-        [&state, &receiver]<::std::size_t... I>(::std::index_sequence<I...>) {
-            Completion()(::std::move(receiver), ::std::move(state.template get<I>())...);
-        }(::std::make_index_sequence<State::size()>{});
-    };
-};
-} // namespace beman::execution::detail
-
-#line 63 "include/beman/execution/detail/just.hpp"
-namespace beman::execution {
-export /* --------- */ using just_t         = ::beman::execution::detail::just_t<::beman::execution::set_value_t>;
-export /* --------- */ using just_error_t   = ::beman::execution::detail::just_t<::beman::execution::set_error_t>;
-export /* --------- */ using just_stopped_t = ::beman::execution::detail::just_t<::beman::execution::set_stopped_t>;
-
-#line 117 "include/beman/execution/detail/just.hpp"
-export /* --------- */ inline constexpr ::beman::execution::just_t just{};
-
-#line 175 "include/beman/execution/detail/just.hpp"
-export /* --------- */ inline constexpr ::beman::execution::just_error_t just_error{};
-
-#line 229 "include/beman/execution/detail/just.hpp"
-export /* --------- */ inline constexpr ::beman::execution::just_stopped_t just_stopped{};
-} // namespace beman::execution
-
-#line 49 "include/beman/execution/detail/let.hpp"
-namespace beman::execution::detail {
-template <typename Completion>
-struct let_t {
-    template <::beman::execution::detail::movable_value Fun>
-    auto operator()(Fun&& fun) const {
-        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Fun>(fun)};
-    }
-    template <::beman::execution::sender Sender, ::beman::execution::detail::movable_value Fun>
-    auto operator()(Sender&& sender, Fun&& fun) const {
-        auto domain(::beman::execution::detail::get_domain_early(sender));
-        return ::beman::execution::detail::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(*this, ::std::forward<Fun>(fun), std::forward<Sender>(sender)));
-    }
-#line 64 "include/beman/execution/detail/let.hpp"
-    template <typename Sender>
-    static auto env(Sender&& sender) {
-        if constexpr (requires {
-                          ::beman::execution::detail::sched_env(
-                              ::beman::execution::get_completion_scheduler<Completion>(
-                                  ::beman::execution::get_env(sender)));
-                      })
-            return ::beman::execution::detail::sched_env(
-                ::beman::execution::get_completion_scheduler<Completion>(::beman::execution::get_env(sender)));
-        else if constexpr (requires {
-                               ::beman::execution::detail::make_env(
-                                   ::beman::execution::get_domain,
-                                   ::beman::execution::get_domain(::beman::execution::get_env(sender)));
-                           })
-            return ::beman::execution::detail::make_env(
-                ::beman::execution::get_domain, ::beman::execution::get_domain(::beman::execution::get_env(sender)));
-        else
-            return ::beman::execution::env<>{};
-    }
-    template <typename Sender, typename Env>
-    static auto join_env(Sender&& sender, Env&& e) -> decltype(auto) {
-        return ::beman::execution::detail::join_env(env(sender), ::beman::execution::detail::fwd_env(e));
-    }
-};
-
-template <typename Completion>
-struct impls_for<::beman::execution::detail::let_t<Completion>> : ::beman::execution::detail::default_impls {
-
-    template <typename Receiver, typename Env>
-    struct let_receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-
-        Receiver& receiver;
-        Env       env;
-
-        auto get_env() const noexcept -> decltype(auto) {
-            return ::beman::execution::detail::join_env(
-                this->env, ::beman::execution::detail::fwd_env(::beman::execution::get_env(this->receiver)));
-        }
-        template <typename Error>
-        auto set_error(Error&& error) && noexcept -> void {
-            ::beman::execution::set_error(::std::move(this->receiver), ::std::forward<Error>(error));
-        }
-        auto set_stopped() && noexcept -> void { ::beman::execution::set_stopped(::std::move(this->receiver)); }
-        template <typename... Args>
-        auto set_value(Args&&... args) && noexcept -> void {
-            ::beman::execution::set_value(::std::move(this->receiver), ::std::forward<Args>(args)...);
-        }
-    };
-
-    template <typename>
-    struct filter_pred : ::std::false_type {};
-    template <typename... A>
-    struct filter_pred<Completion(A...)> : ::std::true_type {};
-    template <typename>
-    struct to_tuple;
-    template <typename C, typename... A>
-    struct to_tuple<C(A...)> {
-        using type = ::beman::execution::detail::decayed_tuple<A...>;
-    };
-    template <typename T>
-    using to_tuple_t = typename to_tuple<T>::type;
-    template <typename Fun, typename Receiver, typename Env>
-    struct to_state {
-        template <typename Tuple>
-        using trans =
-            decltype(::beman::execution::connect(::std::apply(::std::declval<Fun>(), ::std::declval<Tuple>()),
-                                                 ::std::declval<let_receiver<Receiver, Env>>()));
-    };
-
-    static constexpr auto get_state{[]<typename Sender, typename Receiver>(Sender&& sender, Receiver&& receiver) {
-        auto& fun{sender.template get<1>()};
-        auto& child{sender.template get<2>()};
-
-        using fun_t   = ::std::remove_cvref_t<decltype(fun)>;
-        using child_t = ::std::remove_cvref_t<decltype(child)>;
-        using env_t   = decltype(::beman::execution::detail::let_t<Completion>::env(child));
-        using sigs_t = ::beman::execution::completion_signatures_of_t<child_t, ::beman::execution::env_of_t<Receiver>>;
-        using comp_sigs_t = ::beman::execution::detail::meta::filter<filter_pred, sigs_t>;
-        using type_list_t = ::beman::execution::detail::meta::to<::std::variant, comp_sigs_t>;
-        using tuples_t    = ::beman::execution::detail::meta::transform<to_tuple_t, type_list_t>;
-        using unique_t    = ::beman::execution::detail::meta::unique<tuples_t>;
-        using args_t      = ::beman::execution::detail::meta::prepend<std::monostate, unique_t>;
-        using ops_t       = ::beman::execution::detail::meta::prepend<
-                  ::std::monostate,
-                  ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::transform<
-                      to_state<fun_t, ::std::remove_cvref_t<Receiver>, env_t>::template trans,
-                      tuples_t>>>;
-
-        struct state_t {
-            fun_t  fun;
-            env_t  env;
-            args_t args;
-            ops_t  ops2;
-        };
-        return state_t{beman::execution::detail::allocator_aware_move(
-                           ::beman::execution::detail::forward_like<Sender>(fun), receiver),
-                       ::beman::execution::detail::let_t<Completion>::env(child),
-                       {},
-                       {}};
-    }};
-    template <typename Receiver, typename... Args>
-    static auto
-    let_bind(auto& state, Receiver& receiver, Args&&... args) noexcept(noexcept(::beman::execution::connect(
-        ::std::apply(::std::move(state.fun),
-                     ::std::move(state.args.template emplace<::beman::execution::detail::decayed_tuple<Args...>>(
-                         ::std::forward<Args>(args)...))),
-        let_receiver<Receiver, decltype(state.env)>{receiver, state.env}))) {
-        using args_t = ::beman::execution::detail::decayed_tuple<Args...>;
-        auto mkop{[&] {
-            return ::beman::execution::connect(
-                ::std::apply(::std::move(state.fun),
-                             ::std::move(state.args.template emplace<args_t>(::std::forward<Args>(args)...))),
-                let_receiver<Receiver, decltype(state.env)>{receiver, state.env});
-        }};
-        ::beman::execution::start(
-            state.ops2.template emplace<decltype(mkop())>(beman::execution::detail::emplace_from{mkop}));
-    }
-    static constexpr auto complete{
-        []<class Tag, class... Args>(auto, auto& state, auto& receiver, Tag, Args&&... args) {
-            if constexpr (::std::same_as<Tag, Completion>) {
-                try {
-                    let_bind(state, receiver, ::std::forward<Args>(args)...);
-                } catch (...) {
-                    if constexpr (not noexcept(let_bind(state, receiver, ::std::forward<Args>(args)...)))
-                        ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-                }
-            } else {
-                Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
-            }
-        }};
-};
-
-template <typename Completion, typename Fun, typename Sender, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::let_t<Completion>, Fun, Sender>,
-    Env> {
-    template <typename>
-    struct other_completion : ::std::true_type {};
-    template <typename... A>
-    struct other_completion<Completion(A...)> : ::std::false_type {};
-    template <typename>
-    struct matching_completion : ::std::false_type {};
-    template <typename... A>
-    struct matching_completion<Completion(A...)> : ::std::true_type {};
-
-    template <typename>
-    struct apply_decayed;
-    template <typename C, typename... A>
-    struct apply_decayed<C(A...)> {
-        using sender_type = ::beman::execution::detail::call_result_t<Fun, ::std::decay_t<A>...>;
-    };
-    template <typename>
-    struct get_completions;
-    template <template <typename...> class L, typename... C>
-    struct get_completions<L<C...>> {
-        using type = ::beman::execution::detail::meta::unique<
-            ::beman::execution::detail::meta::combine<decltype(::beman::execution::get_completion_signatures(
-                std::declval<typename apply_decayed<C>::sender_type>(), std::declval<Env>()))...>>;
-    };
-
-    using upstream_env = decltype(::beman::execution::detail::let_t<Completion>::join_env(::std::declval<Sender>(),
-                                                                                          ::std::declval<Env>()));
-    using upstream_completions = decltype(::beman::execution::get_completion_signatures(
-        ::std::declval<Sender>(), ::std::declval<upstream_env>()));
-    using other_completions    = ::beman::execution::detail::meta::filter<other_completion, upstream_completions>;
-    using matching_completions = ::beman::execution::detail::meta::filter<matching_completion, upstream_completions>;
-    using type = ::beman::execution::detail::meta::combine<typename get_completions<matching_completions>::type,
-                                                           other_completions>;
-};
-} // namespace beman::execution::detail
-
-#line 238 "include/beman/execution/detail/let.hpp"
-namespace beman::execution {
-export /* --------- */ using let_error_t   = ::beman::execution::detail::let_t<::beman::execution::set_error_t>;
-export /* --------- */ using let_stopped_t = ::beman::execution::detail::let_t<::beman::execution::set_stopped_t>;
-export /* --------- */ using let_value_t   = ::beman::execution::detail::let_t<::beman::execution::set_value_t>;
-
-export /* --------- */ inline constexpr ::beman::execution::let_error_t   let_error{};
-export /* --------- */ inline constexpr ::beman::execution::let_stopped_t let_stopped{};
-export /* --------- */ inline constexpr ::beman::execution::let_value_t   let_value{};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/read_env.hpp"
-namespace beman::execution::detail {
-struct read_env_t {
-    auto operator()(auto&& query) const { return ::beman::execution::detail::make_sender(*this, query); }
-    template <::beman::execution::sender Sender>
-    static auto affine_on(Sender&& sndr, const auto&) noexcept {
-        return ::std::forward<Sender>(sndr);
-    }
-};
-
-template <>
-struct impls_for<::beman::execution::detail::read_env_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto start = [](auto query, auto& receiver) noexcept -> void {
-        try {
-            auto env{::beman::execution::get_env(receiver)};
-            ::beman::execution::set_value(::std::move(receiver), query(env));
-        } catch (...) {
-            ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-        }
-    };
-};
-
-template <typename Query, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::read_env_t, Query>,
-    Env> {
-    using set_value_type =
-        ::beman::execution::set_value_t(decltype(::std::declval<Query>()(::std::as_const(::std::declval<Env>()))));
-    using set_error_type = ::beman::execution::set_error_t(::std::exception_ptr);
-    using type           = ::std::conditional_t<noexcept(::std::declval<Query>()(::std::declval<const Env&>())),
-                                                ::beman::execution::completion_signatures<set_value_type>,
-                                                ::beman::execution::completion_signatures<set_value_type, set_error_type>>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using read_env_t = beman::execution::detail::read_env_t;
-export /* --------- */ inline constexpr read_env_t read_env{};
-} // namespace beman::execution
-
-#line 47 "include/beman/execution/detail/schedule_from.hpp"
-namespace beman::execution::detail {
-struct schedule_from_t {
-    template <::beman::execution::scheduler Scheduler, ::beman::execution::sender Sender>
-    auto operator()(Scheduler&& scheduler, Sender&& sender) const {
-        auto domain{::beman::execution::detail::query_with_default(
-            ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{})};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this, ::std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
-    }
-};
-
-template <>
-struct impls_for<::beman::execution::detail::schedule_from_t> : ::beman::execution::detail::default_impls {
-    template <typename State>
-    struct upstream_receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-        State* state;
-
-        auto set_value() && noexcept -> void {
-            try {
-                ::std::visit(
-                    [this]<typename Tuple>(Tuple& result) noexcept -> void {
-                        if constexpr (!::std::same_as<::std::monostate, Tuple>) {
-                            ::std::apply(
-                                [this](auto&& tag, auto&&... args) {
-                                    tag(::std::move(this->state->receiver), ::std::move(args)...);
-                                },
-                                result);
-                        }
-                    },
-                    state->async_result);
-            } catch (...) {
-                ::beman::execution::set_error(::std::move(state->receiver), ::std::current_exception());
-            }
-        }
-#line 85 "include/beman/execution/detail/schedule_from.hpp"
-        template <typename Error>
-        auto set_error(Error&& err) && noexcept -> void {
-            ::beman::execution::set_error(std::move(state->receiver), std::forward<Error>(err));
-        }
-#line 90 "include/beman/execution/detail/schedule_from.hpp"
-        auto set_stopped() && noexcept -> void { ::beman::execution::set_stopped(std::move(state->receiver)); }
-
-        auto get_env() const noexcept -> decltype(auto) {
-            return ::beman::execution::detail::fwd_env(::beman::execution::get_env(state->receiver));
-        }
-    };
-    template <typename Receiver, typename Variant>
-    struct state_base {
-        Receiver receiver;
-        Variant  async_result{};
-    };
-    template <typename Receiver, typename Scheduler, typename Variant>
-    struct state_type : state_base<Receiver, Variant> {
-        using receiver_t = upstream_receiver<state_base<Receiver, Variant>>;
-        using operation_t =
-            ::beman::execution::connect_result_t<::beman::execution::schedule_result_t<Scheduler>, receiver_t>;
-        operation_t op_state;
-
-        static constexpr bool nothrow() {
-            return noexcept(::beman::execution::connect(::beman::execution::schedule(::std::declval<Scheduler>()),
-                                                        receiver_t{nullptr}));
-        }
-        explicit state_type(Scheduler& sch, Receiver& rcvr) noexcept(nothrow())
-            : state_base<Receiver, Variant>{rcvr},
-              op_state(::beman::execution::connect(::beman::execution::schedule(sch), receiver_t{this})) {}
-    };
-
-    static constexpr auto get_attrs{[](const auto& data, const auto& child) noexcept -> decltype(auto) {
-        return ::beman::execution::detail::join_env(
-            ::beman::execution::detail::sched_attrs(data),
-            ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
-    }};
-    static constexpr auto get_state{
-        []<typename Sender, typename Receiver>(Sender&& sender, Receiver& receiver)
-            requires ::beman::execution::sender_in<::beman::execution::detail::child_type<Sender>,
-                                                   ::beman::execution::env_of_t<Receiver>>
-        {
-            auto sch{sender.template get<1>()};
-
-            using sched_t   = ::std::remove_cvref_t<decltype(sch)>;
-            using variant_t = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
-                ::std::monostate,
-                ::beman::execution::detail::meta::transform<
-                    ::beman::execution::detail::as_tuple_t,
-                    ::beman::execution::detail::meta::to<::std::variant,
-                                                         ::beman::execution::detail::meta::combine<
-                                                             ::beman::execution::completion_signatures_of_t<
-                                                                 ::beman::execution::detail::child_type<Sender>,
-                                                                 ::beman::execution::env_of_t<Receiver>>,
-
-                                                             ::beman::execution::completion_signatures<
-                                                                 ::beman::execution::set_error_t(::std::exception_ptr),
-                                                                 ::beman::execution::set_stopped_t()>>>>>>;
-
-            return state_type<Receiver, sched_t, variant_t>(sch, receiver);
-        }};
-    static constexpr auto complete{
-        []<typename Tag, typename... Args>(auto, auto& state, auto& receiver, Tag, Args&&... args) noexcept -> void {
-            using result_t         = ::beman::execution::detail::decayed_tuple<Tag, Args...>;
-            constexpr bool nothrow = ::std::is_nothrow_constructible_v<result_t, Tag, Args...>;
-
-            try {
-                [&]() noexcept(nothrow) {
-                    state.async_result.template emplace<result_t>(Tag(), std::forward<Args>(args)...);
-                }();
-            } catch (...) {
-                if constexpr (not nothrow)
-                    ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-            }
-#line 160 "include/beman/execution/detail/schedule_from.hpp"
-            if (state.async_result.index() == 0)
-                return;
-
-            ::beman::execution::start(state.op_state);
-        }};
-};
-
-template <typename Scheduler, typename Sender, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::schedule_from_t, Scheduler, Sender>,
-    Env> {
-    using scheduler_sender = decltype(::beman::execution::schedule(::std::declval<Scheduler>()));
-    template <typename... E>
-    using as_set_error = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
-    using type         = ::beman::execution::detail::meta::combine<
-                decltype(::beman::execution::get_completion_signatures(::std::declval<Sender>(), ::std::declval<Env>())),
-                ::beman::execution::error_types_of_t<scheduler_sender, Env, as_set_error>,
-                ::beman::execution::completion_signatures<::beman::execution::set_error_t(::std::exception_ptr)>>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using schedule_from_t = beman::execution::detail::schedule_from_t;
-export /* --------- */ inline constexpr ::beman::execution::schedule_from_t schedule_from{};
-} // namespace beman::execution
-
-#line 40 "include/beman/execution/detail/split.hpp"
-namespace beman::execution::detail {
-
-struct split_impl_t {};
-template <>
-struct impls_for<split_impl_t> : ::beman::execution::detail::default_impls {
-
-    template <class Sndr>
-    struct shared_state;
-
-    struct split_env {
-        ::beman::execution::inplace_stop_source* stop_source;
-
-        ::beman::execution::inplace_stop_token query(::beman::execution::get_stop_token_t) const noexcept {
-            return stop_source->get_token();
-        }
-    };
-
-    struct local_state_base {
-        local_state_base* next{nullptr};
-        virtual auto      notify() noexcept -> void = 0;
-
-        local_state_base() noexcept                                  = default;
-        local_state_base(const local_state_base&)                    = delete;
-        local_state_base(local_state_base&&)                         = delete;
-        auto operator=(const local_state_base&) -> local_state_base& = delete;
-        auto operator=(local_state_base&&) -> local_state_base&      = delete;
-
-      protected:
-        ~local_state_base() = default;
-    };
-
-    template <class Sndr>
-    struct split_receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-
-        explicit split_receiver(shared_state<Sndr>* state) noexcept : sh_state(state) {
-            if (sh_state) {
-                sh_state->inc_ref();
-            }
-        }
-#line 81 "include/beman/execution/detail/split.hpp"
-        ~split_receiver() noexcept {
-            if (sh_state) {
-                sh_state->dec_ref();
-            }
-        }
-#line 87 "include/beman/execution/detail/split.hpp"
-        split_receiver(split_receiver&& other) noexcept : sh_state(::std::exchange(other.sh_state, nullptr)) {}
-        split_receiver& operator=(split_receiver&& other) noexcept {
-            sh_state = ::std::exchange(other.sh_state, nullptr);
-            return *this;
-        }
-#line 93 "include/beman/execution/detail/split.hpp"
-        split_receiver(const split_receiver&)            = delete;
-        split_receiver& operator=(const split_receiver&) = delete;
-
-        template <class Tag, class... Args>
-        void complete(Tag, Args&&... args) noexcept {
-            using tuple_t = ::beman::execution::detail::decayed_tuple<Tag, Args...>;
-            try {
-                sh_state->result.template emplace<tuple_t>(Tag(), ::std::forward<Args>(args)...);
-            } catch (...) {
-                using tuple_err = ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>;
-                sh_state->result.template emplace<tuple_err>(::beman::execution::set_error,
-                                                             ::std::current_exception());
-            }
-            sh_state->notify();
-        }
-#line 109 "include/beman/execution/detail/split.hpp"
-        template <class... Args>
-        void set_value(Args&&... args) && noexcept {
-            complete(::beman::execution::set_value, ::std::forward<Args>(args)...);
-        }
-#line 114 "include/beman/execution/detail/split.hpp"
-        template <class Error>
-        void set_error(Error&& err) && noexcept {
-            complete(::beman::execution::set_error, ::std::forward<Error>(err));
-        }
-#line 119 "include/beman/execution/detail/split.hpp"
-        void set_stopped() && noexcept { complete(::beman::execution::set_stopped); }
-
-        split_env get_env() const noexcept { return split_env{&sh_state->stop_src}; }
-
-        shared_state<Sndr>* sh_state;
-    };
-
-#line 127 "include/beman/execution/detail/split.hpp"
-    template <class Sndr>
-    struct shared_state {
-        template <class... Args>
-        using value_tuple = ::std::tuple<::beman::execution::set_value_t, ::std::decay_t<Args>...>;
-
-        template <class... Args>
-        using error_tuples = ::std::variant<::std::tuple<::beman::execution::set_error_t, ::std::decay_t<Args>>...>;
-
-        using variant_type = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::combine<
-            ::std::variant<::std::monostate>,
-            ::std::variant<::std::tuple<::beman::execution::set_stopped_t>>,
-            ::std::variant<::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>>,
-            ::beman::execution::error_types_of_t<Sndr, split_env, error_tuples>,
-            ::beman::execution::value_types_of_t<Sndr, split_env, value_tuple>>>;
-
-        using state_list_type = ::beman::execution::detail::atomic_intrusive_stack<&local_state_base::next>;
-
-        using child_operation_state = ::beman::execution::connect_result_t<Sndr, split_receiver<Sndr>>;
-
-        explicit shared_state(Sndr&& sndr) {
-            try {
-                op_state.emplace(::beman::execution::detail::emplace_from{[&] {
-                    return ::beman::execution::connect(::std::forward<Sndr>(sndr), split_receiver<Sndr>{this});
-                }});
-            } catch (...) {
-                using error_tuple_t = ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>;
-                result.template emplace<error_tuple_t>(::beman::execution::set_error, ::std::current_exception());
-                [[maybe_unused]] auto queue = waiting_states.pop_all_and_shutdown();
-                assert(queue.empty());
-            }
-        }
-#line 163 "include/beman/execution/detail/split.hpp"
-        void add_listener(local_state_base* listener) noexcept {
-
-#line 166 "include/beman/execution/detail/split.hpp"
-            if (auto maybe_ptr = waiting_states.try_push(listener); !maybe_ptr) {
-
-                listener->notify();
-            } else if (!(*maybe_ptr)) {
-
-                assert(op_state);
-                if (op_state)
-                    ::beman::execution::start(*op_state);
-                else
-                    std::terminate();
-            }
-        }
-#line 179 "include/beman/execution/detail/split.hpp"
-        void notify() noexcept {
-
-#line 183 "include/beman/execution/detail/split.hpp"
-            op_state.reset();
-            auto listeners = waiting_states.pop_all_and_shutdown();
-            while (auto listener = listeners.pop()) {
-                listener->notify();
-            }
-        }
-#line 190 "include/beman/execution/detail/split.hpp"
-        void inc_ref() noexcept { ref_count.fetch_add(1); }
-
-#line 201 "include/beman/execution/detail/split.hpp"
-        void dec_ref() noexcept {
-            std::size_t count = ref_count.load();
-            if (count == 2 && waiting_states.empty_and_not_shutdown()) {
-                assert(op_state);
-                [[maybe_unused]] auto listeners = waiting_states.pop_all_and_shutdown();
-                assert(listeners.empty());
-                op_state.reset();
-            }
-            if (ref_count.fetch_sub(1) == 1) {
-                delete this;
-            }
-        }
-#line 214 "include/beman/execution/detail/split.hpp"
-        ::beman::execution::inplace_stop_source stop_src{};
-        variant_type                            result{};
-        state_list_type                         waiting_states{};
-        ::std::atomic<::std::size_t>            ref_count{0};
-        ::std::optional<child_operation_state>  op_state{};
-    };
-
-    template <class Sndr, class Receiver>
-    struct local_state final : local_state_base {
-        using stop_token_type = ::beman::execution::stop_token_of_t<::beman::execution::env_of_t<Receiver>>;
-
-        struct on_stop_type {
-            shared_state<Sndr>* sh_state;
-            void                operator()() noexcept { sh_state->stop_src.request_stop(); }
-        };
-
-        using on_stop_callback = ::beman::execution::stop_callback_for_t<stop_token_type, on_stop_type>;
-
-        explicit local_state(shared_state<Sndr>* state, Receiver& rcvr) noexcept
-            : sh_state(state), receiver{std::addressof(rcvr)} {
-            sh_state->inc_ref();
-        }
-#line 237 "include/beman/execution/detail/split.hpp"
-        ~local_state() noexcept { sh_state->dec_ref(); }
-
-        local_state(const local_state&)            = delete;
-        local_state& operator=(const local_state&) = delete;
-        local_state(local_state&&)                 = delete;
-        local_state& operator=(local_state&&)      = delete;
-
-        auto notify() noexcept -> void override {
-            on_stop.reset();
-            auto stop_token = ::beman::execution::get_stop_token(::beman::execution::get_env(receiver));
-            if (stop_token.stop_requested()) {
-                ::beman::execution::set_stopped(std::move(*receiver));
-            } else {
-                assert(sh_state->result.index() > 0);
-                assert(!sh_state->result.valueless_by_exception());
-                try {
-                    ::std::visit(
-                        [&]<class Arg>(const Arg& arg) noexcept -> void {
-                            if constexpr (!::std::same_as<::std::decay_t<Arg>, ::std::monostate>) {
-                                ::std::apply(
-                                    [&](auto tag, const auto&... args) noexcept -> void {
-                                        tag(::std::move(*receiver), args...);
-                                    },
-                                    arg);
-                            }
-                        },
-                        sh_state->result);
-                } catch (...) {
-
-#line 267 "include/beman/execution/detail/split.hpp"
-                    std::terminate();
-                }
-            }
-        }
-#line 272 "include/beman/execution/detail/split.hpp"
-        void start() noexcept {
-            on_stop.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(*receiver)),
-                            on_stop_type{sh_state});
-            sh_state->add_listener(this);
-        }
-#line 278 "include/beman/execution/detail/split.hpp"
-        std::optional<on_stop_callback> on_stop;
-        shared_state<Sndr>*             sh_state;
-        Receiver*                       receiver;
-    };
-
-    static constexpr auto get_state = []<typename Sender, typename Receiver>(Sender&&  sender,
-                                                                             Receiver& receiver) noexcept {
-        auto&& wrapper = sender.template get<1>();
-        return local_state(wrapper.sh_state, receiver);
-    };
-
-    static constexpr auto start = []<class Sndr, class Rcvr>(local_state<Sndr, Rcvr>& state, Rcvr&) noexcept {
-        state.start();
-    };
-};
-
-template <class Sndr>
-struct shared_wrapper {
-    explicit shared_wrapper(impls_for<split_impl_t>::shared_state<Sndr>* state) noexcept : sh_state(state) {
-        if (sh_state) {
-            sh_state->inc_ref();
-        }
-    }
-#line 302 "include/beman/execution/detail/split.hpp"
-    ~shared_wrapper() noexcept {
-        if (sh_state) {
-            sh_state->dec_ref();
-        }
-    }
-#line 308 "include/beman/execution/detail/split.hpp"
-    shared_wrapper(const shared_wrapper& other) noexcept : sh_state(other.sh_state) {
-        if (sh_state) {
-            sh_state->inc_ref();
-        }
-    }
-#line 314 "include/beman/execution/detail/split.hpp"
-    shared_wrapper(shared_wrapper&& other) noexcept : sh_state(::std::exchange(other.sh_state, nullptr)) {}
-
-    shared_wrapper& operator=(const shared_wrapper& other) noexcept {
-
-#line 319 "include/beman/execution/detail/split.hpp"
-        if (this == &other) {
-            return *this;
-        }
-        auto tmp = other;
-        ::std::swap(sh_state, tmp.sh_state);
-        return *this;
-    }
-#line 327 "include/beman/execution/detail/split.hpp"
-    shared_wrapper& operator=(shared_wrapper&& other) noexcept {
-        auto tmp = ::std::move(other);
-        ::std::swap(sh_state, tmp.sh_state);
-        return *this;
-    }
-#line 333 "include/beman/execution/detail/split.hpp"
-    impls_for<split_impl_t>::shared_state<Sndr>* sh_state;
-};
-
-struct split_t {
-    template <class Sndr>
-    auto transform_sender(Sndr&& sndr) const {
-        auto&& child       = ::std::forward<Sndr>(sndr).template get<2>();
-        using child_type   = decltype(child);
-        using shared_state = ::beman::execution::detail::impls_for<split_impl_t>::shared_state<child_type>;
-        auto* sh_state     = new shared_state{::beman::execution::detail::forward_like<Sndr>(child)};
-        return ::beman::execution::detail::make_sender(split_impl_t{}, shared_wrapper<child_type>{sh_state});
-    }
-#line 346 "include/beman/execution/detail/split.hpp"
-    template <class Sender>
-        requires beman::execution::sender_in<Sender, impls_for<split_impl_t>::split_env>
-    auto operator()(Sender&& sender) const {
-        auto domain{::beman::execution::detail::get_domain_early(sender)};
-        return ::beman::execution::transform_sender(
-            domain, ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)));
-    }
-};
-
-template <class Sndr, class Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::split_impl_t,
-                                             ::beman::execution::detail::shared_wrapper<Sndr>>,
-    Env> {
-    template <class... Args>
-    using make_value_completions =
-        ::beman::execution::completion_signatures<::beman::execution::set_value_t(const std::decay_t<Args>&...)>;
-
-    template <class... Args>
-    using make_error_completions =
-        ::beman::execution::completion_signatures<::beman::execution::set_error_t(const std::decay_t<Args>&)...>;
-
-    using value_completions = ::beman::execution::
-        value_types_of_t<Sndr, Env, make_value_completions, ::beman::execution::detail::meta::combine>;
-
-    using error_completions = ::beman::execution::error_types_of_t<Sndr, Env, make_error_completions>;
-
-    using fixed_completions =
-        ::beman::execution::completion_signatures<::beman::execution::set_stopped_t(),
-                                                  ::beman::execution::set_error_t(std::exception_ptr)>;
-
-    using type = ::beman::execution::detail::meta::unique<
-        ::beman::execution::detail::meta::combine<fixed_completions, value_completions, error_completions>>;
-};
-
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using split_t = ::beman::execution::detail::split_t;
-
-export /* --------- */ inline constexpr ::beman::execution::split_t split{};
-} // namespace beman::execution
-
-#line 37 "include/beman/execution/detail/then.hpp"
-namespace beman::execution::detail {
-template <typename Completion>
-struct then_t : ::beman::execution::sender_adaptor_closure<then_t<Completion>> {
-    template <::beman::execution::detail::movable_value Fun>
-    auto operator()(Fun&& fun) const {
-        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Fun>(fun)};
-    }
-    template <::beman::execution::sender Sender, ::beman::execution::detail::movable_value Fun>
-    auto operator()(Sender&& sender, Fun&& fun) const {
-        auto domain{::beman::execution::detail::get_domain_early(sender)};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(*this, ::std::forward<Fun>(fun), ::std::forward<Sender>(sender)));
-    }
-    template <::beman::execution::sender Sender, typename Env>
-        requires ::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>
-    static auto affine_on(Sender&& sndr, const Env&) noexcept {
-        return ::std::forward<Sender>(sndr);
-    }
-};
-
-template <typename Completion>
-struct impls_for<then_t<Completion>> : ::beman::execution::detail::default_impls {
-    // NOLINTBEGIN(bugprone-exception-escape)
-    static constexpr auto complete =
-        []<typename Tag, typename... Args>(auto, auto& fun, auto& receiver, Tag, Args&&... args) noexcept -> void {
-        if constexpr (::std::same_as<Completion, Tag>) {
-            try {
-                auto invoke = [&] { return ::std::invoke(::std::move(fun), ::std::forward<Args>(args)...); };
-                if constexpr (::std::same_as<void, decltype(invoke())>) {
-                    invoke();
-                    ::beman::execution::set_value(::std::move(receiver));
-                } else {
-                    ::beman::execution::set_value(::std::move(receiver), invoke());
-                }
-            } catch (...) {
-                if constexpr (not noexcept(::std::invoke(::std::move(fun), ::std::forward<Args>(args)...)
-
-                                               )) {
-                    static_assert(
-                        noexcept(::beman::execution::set_error(::std::move(receiver), ::std::current_exception())));
-                    ::beman::execution::set_error(::std::move(receiver), ::std::current_exception());
-                }
-            }
-        } else {
-            static_assert(noexcept(Tag()(::std::move(receiver), ::std::forward<Args>(args)...)));
-            Tag()(::std::move(receiver), ::std::forward<Args>(args)...);
-        }
-    };
-    // NOLINTEND(bugprone-exception-escape)
-};
-
-template <typename T>
-struct then_set_value {
-    using type = ::beman::execution::set_value_t(T);
-};
-template <>
-struct then_set_value<void> {
-    using type = ::beman::execution::set_value_t();
-};
-
-template <typename, typename, typename Completion>
-struct then_transform {
-    using type = Completion;
-};
-
-template <typename Fun, typename Completion, typename... T>
-struct then_transform<Fun, Completion, Completion(T...)> {
-    using type = typename ::beman::execution::detail::then_set_value<
-        ::beman::execution::detail::call_result_t<Fun, T...>>::type;
-};
-
-template <typename Fun, typename Replace>
-struct then_transform_t {
-    template <typename Completion>
-    using transform = typename ::beman::execution::detail::then_transform<Fun, Replace, Completion>::type;
-};
-
-template <typename, typename, typename>
-struct then_exception_fun : ::std::false_type {};
-template <typename Comp, typename Fun, typename... A>
-struct then_exception_fun<Comp, Fun, Comp(A...)>
-    : ::std::bool_constant<not noexcept(::std::declval<Fun>()(::std::declval<A>()...))> {};
-
-template <typename, typename, typename>
-struct then_exception : ::std::false_type {};
-template <typename Comp, typename Fun, typename Completion, typename... Completions>
-struct then_exception<Comp, Fun, ::beman::execution::completion_signatures<Completion, Completions...>> {
-    static constexpr bool value{
-        then_exception_fun<Comp, Fun, Completion>::value ||
-        then_exception<Comp, Fun, ::beman::execution::completion_signatures<Completions...>>::value};
-};
-
-template <typename Completion, typename Fun, typename Sender, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::then_t<Completion>, Fun, Sender>,
-    Env> {
-    using type = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::combine<
-        ::beman::execution::detail::meta::transform<
-            ::beman::execution::detail::then_transform_t<Fun, Completion>::template transform,
-            ::beman::execution::completion_signatures_of_t<Sender, Env>>,
-        ::std::conditional_t<
-            ::beman::execution::detail::
-                then_exception<Completion, Fun, ::beman::execution::completion_signatures_of_t<Sender, Env>>::value,
-            ::beman::execution::completion_signatures<::beman::execution::set_error_t(::std::exception_ptr)>,
-            ::beman::execution::completion_signatures<>>>>;
-};
-} // namespace beman::execution::detail
-
-#line 148 "include/beman/execution/detail/then.hpp"
-namespace beman::execution {
-
-#line 153 "include/beman/execution/detail/then.hpp"
-export /* --------- */ using then_t = ::beman::execution::detail::then_t<::beman::execution::set_value_t>;
-
-#line 158 "include/beman/execution/detail/then.hpp"
-export /* --------- */ using upon_error_t = ::beman::execution::detail::then_t<::beman::execution::set_error_t>;
-
-#line 163 "include/beman/execution/detail/then.hpp"
-export /* --------- */ using upon_stopped_t = ::beman::execution::detail::then_t<::beman::execution::set_stopped_t>;
-
-#line 215 "include/beman/execution/detail/then.hpp"
-export /* --------- */ inline constexpr ::beman::execution::then_t then{};
-
-#line 269 "include/beman/execution/detail/then.hpp"
-export /* --------- */ inline constexpr ::beman::execution::upon_error_t upon_error{};
-
-#line 320 "include/beman/execution/detail/then.hpp"
-export /* --------- */ inline constexpr ::beman::execution::upon_stopped_t upon_stopped{};
-} // namespace beman::execution
-
-#line 51 "include/beman/execution/detail/when_all.hpp"
-namespace beman::execution::detail {
-struct when_all_t {
-    template <::beman::execution::sender... Sender>
-        requires(0u != sizeof...(Sender)) &&
-                ((::beman::execution::detail::meta::size_v<
-                      ::beman::execution::value_types_of_t<Sender,
-                                                           ::beman::execution::env<>,
-                                                           ::std::tuple,
-                                                           ::beman::execution::detail::type_list>> == 1u) &&
-                 ...) &&
-                requires(Sender&&... s) {
-                    typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(s))...>;
-                }
-    auto operator()(Sender&&... sender) const {
-        using common_t =
-            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
-        return ::beman::execution::transform_sender(
-            common_t(), ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)...));
-    }
-};
-
-template <typename>
-struct when_all_value_types;
-template <typename... T>
-struct when_all_value_types<::beman::execution::detail::type_list<T...>> {
-    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t(T...)>;
-};
-
-template <>
-struct impls_for<::beman::execution::detail::when_all_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_attrs{[](auto&&, auto&&... sender) {
-        using common_t =
-            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
-        if constexpr (::std::same_as<common_t, ::beman::execution::default_domain>)
-            return ::beman::execution::env<>{};
-        else
-            return ::beman::execution::detail::make_env(::beman::execution::get_domain, common_t{});
-    }};
-    static constexpr auto get_env{
-        []<typename State, typename Receiver>(auto&&, State& state, const Receiver& receiver) noexcept {
-            return ::beman::execution::detail::join_env(
-                ::beman::execution::detail::make_env(::beman::execution::get_stop_token, state.stop_src.get_token()),
-                ::beman::execution::get_env(receiver));
-        }};
-
-    enum class disposition : unsigned char { started, error, stopped };
-
-    template <typename Receiver, typename... Sender>
-    struct state_type {
-        struct nonesuch {};
-        using env_t        = ::beman::execution::env_of_t<Receiver>;
-        using values_tuple = ::std::tuple<
-            ::beman::execution::
-                value_types_of_t<Sender, env_t, ::beman::execution::detail::decayed_tuple, ::std::optional>...>;
-        using errors_variant = ::beman::execution::detail::meta::to<
-            ::std::variant,
-            ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
-                nonesuch,
-                ::beman::execution::detail::meta::prepend<
-                    ::std::exception_ptr,
-                    ::beman::execution::detail::meta::combine<::beman::execution::detail::meta::to<
-                        ::beman::execution::detail::type_list,
-                        ::beman::execution::detail::meta::combine<::beman::execution::error_types_of_t<
-                            Sender,
-                            env_t,
-                            ::beman::execution::detail::decayed_type_list>...>>>>>>>;
-        using stop_callback = ::beman::execution::stop_callback_for_t<
-            ::beman::execution::stop_token_of_t<::beman::execution::env_of_t<Receiver>>,
-            ::beman::execution::detail::on_stop_request<state_type>>;
-
-        void arrive(Receiver& recvr) noexcept {
-            if (0u == --count)
-                this->complete(recvr);
-        }
-#line 126 "include/beman/execution/detail/when_all.hpp"
-        void complete(Receiver& recvr) noexcept {
-            switch (disposition(this->disp)) {
-            case disposition::started: {
-                auto tie = []<typename... T>(::std::tuple<T...>& t) noexcept {
-                    return ::std::apply([](auto&... a) { return ::std::tie(a...); }, t);
-                };
-                auto set = [&](auto&... t) noexcept {
-                    ::beman::execution::set_value(::std::move(recvr), ::std::move(t)...);
-                };
-
-                this->on_stop.reset();
-                ::std::apply([&](auto&... opts) noexcept { ::std::apply(set, ::std::tuple_cat(tie(*opts)...)); },
-                             this->values);
-            } break;
-            case disposition::error:
-                this->on_stop.reset();
-                try {
-                    ::std::visit(
-                        [&]<typename Error>(Error& error) noexcept {
-                            if constexpr (!::std::same_as<Error, nonesuch>) {
-                                ::beman::execution::set_error(::std::move(recvr), ::std::move(error));
-                            }
-                        },
-                        this->errors);
-                } catch (...) {
-                    ::beman::execution::set_error(::std::move(recvr), ::std::current_exception());
-                }
-                break;
-            case disposition::stopped:
-                this->on_stop.reset();
-                ::beman::execution::set_stopped(::std::move(recvr));
-                break;
-            }
-        }
-#line 161 "include/beman/execution/detail/when_all.hpp"
-        auto request_stop() -> void {
-            if (1u == ++this->count)
-                --this->count;
-            else {
-                this->stop_src.request_stop();
-                this->arrive(*this->receiver);
-            }
-        }
-#line 170 "include/beman/execution/detail/when_all.hpp"
-        Receiver*                               receiver{};
-        ::std::atomic<::std::size_t>            count{sizeof...(Sender)};
-        ::beman::execution::inplace_stop_source stop_src{};
-        ::std::atomic<disposition>              disp{disposition::started};
-        errors_variant                          errors{};
-        values_tuple                            values{};
-        ::std::optional<stop_callback>          on_stop{::std::nullopt};
-    };
-
-    template <typename Receiver>
-    struct make_state {
-        template <::beman::execution::sender_in<::beman::execution::env_of_t<Receiver>>... Sender>
-        auto operator()(auto, auto, Sender&&...) const {
-            return state_type<Receiver, Sender...>{};
-        }
-    };
-    static constexpr auto get_state{[]<typename Sender, typename Receiver>(Sender&& sender, Receiver&) noexcept(
-                                        noexcept(std::forward<Sender>(sender).apply(make_state<Receiver>{}))) {
-        return std::forward<Sender>(sender).apply(make_state<Receiver>{});
-    }};
-    static constexpr auto start{[]<typename State, typename Receiver, typename... Ops>(
-                                    State& state, Receiver& receiver, Ops&... ops) noexcept -> void {
-        state.receiver = &receiver;
-        state.on_stop.emplace(::beman::execution::get_stop_token(::beman::execution::get_env(receiver)),
-                              ::beman::execution::detail::on_stop_request{state});
-        if (state.stop_src.stop_requested()) {
-            state.on_stop.reset();
-            ::beman::execution::set_stopped(std::move(receiver));
-        } else {
-            (::beman::execution::start(ops), ...);
-        }
-    }};
-    static constexpr auto complete{
-        []<typename Index, typename State, typename Receiver, typename Set, typename... Args>(
-            Index, State& state, Receiver& receiver, Set, Args&&... args) noexcept -> void {
-            if constexpr (::std::same_as<Set, ::beman::execution::set_error_t>) {
-                if (disposition::error != state.disp.exchange(disposition::error)) {
-                    state.stop_src.request_stop();
-                    try {
-                        state.errors.template emplace<typename ::std::decay<Args...>::type>(
-                            ::std::forward<Args>(args)...);
-                    } catch (...) {
-                        state.errors.template emplace<::std::exception_ptr>(::std::current_exception());
-                    }
-                }
-            } else if constexpr (::std::same_as<Set, ::beman::execution::set_stopped_t>) {
-                auto expected = disposition::started;
-                if (state.disp.compare_exchange_strong(expected, disposition::stopped)) {
-                    state.stop_src.request_stop();
-                }
-            } else if constexpr (!::std::same_as<decltype(State::values), ::std::tuple<>>) {
-                if (state.disp == disposition::started) {
-                    auto& opt = ::std::get<Index::value>(state.values);
-                    try {
-                        opt.emplace(::std::forward<Args>(args)...);
-                    } catch (...) {
-                        if (disposition::error != state.disp.exchange(disposition::error)) {
-                            state.stop_src.request_stop();
-                            state.errors.template emplace<::std::exception_ptr>(::std::current_exception());
-                        }
-                    }
-                }
-            }
-            state.arrive(receiver);
-        }};
-};
-
-template <typename Data, typename Env, typename... Sender>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::when_all_t, Data, Sender...>,
-    Env> {
-    template <typename... E>
-    struct error_comps_t {
-        using type = ::beman::execution::completion_signatures<::beman::execution::set_error_t(E)...>;
-    };
-    template <typename... E>
-    using error_comps = typename error_comps_t<E...>::type;
-
-    using value_types =
-        typename ::beman::execution::detail::when_all_value_types<::beman::execution::detail::meta::combine<
-            ::beman::execution::
-                value_types_of_t<Sender, Env, ::beman::execution::detail::type_list, ::std::type_identity_t>...>>::
-            type;
-    using error_types = ::beman::execution::detail::meta::unique<
-        ::beman::execution::detail::meta::combine<::beman::execution::error_types_of_t<Sender, Env, error_comps>...>>;
-    using stopped_types =
-        ::std::conditional_t<(false || ... || ::beman::execution::sends_stopped<Sender, Env>),
-                             ::beman::execution::completion_signatures<::beman::execution::set_stopped_t()>,
-                             ::beman::execution::completion_signatures<>>;
-    using type = ::beman::execution::detail::meta::combine<value_types, error_types, stopped_types>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using when_all_t = ::beman::execution::detail::when_all_t;
-export /* --------- */ inline constexpr ::beman::execution::when_all_t when_all{};
-} // namespace beman::execution
-
-#line 21 "include/beman/execution/detail/write_env.hpp"
-namespace beman::execution::detail {
-struct write_env_t {
-    template <::beman::execution::sender Sender, ::beman::execution::detail::queryable Env>
-    constexpr auto operator()(Sender&& sender, Env&& env) const {
-        return ::beman::execution::detail::make_sender(
-            *this, ::std::forward<Env>(env), ::std::forward<Sender>(sender));
-    }
-    static auto name() { return "write_env_t"; }
-    template <::beman::execution::sender Sender, typename Env>
-        requires ::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>
-    static auto affine_on(Sender&& sndr, const Env&) noexcept {
-        return ::std::forward<Sender>(sndr);
-    }
-};
-
-template <typename NewEnv, typename Child, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::write_env_t, NewEnv, Child>,
-    Env> {
-    using type = decltype(::beman::execution::get_completion_signatures(
-        ::std::declval<Child>(),
-        ::beman::execution::detail::join_env(::std::declval<NewEnv>(), ::std::declval<Env>())));
-};
-
-template <>
-struct impls_for<write_env_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_env = [](auto, const auto& state, const auto& receiver) noexcept {
-        return ::beman::execution::detail::join_env(state, ::beman::execution::get_env(receiver));
-    };
-};
-
-inline constexpr write_env_t write_env{};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using write_env_t = ::beman::execution::detail::write_env_t;
-export /* --------- */ inline constexpr write_env_t write_env{};
-} // namespace beman::execution
-
-#line 23 "include/beman/execution/detail/associate.hpp"
-namespace beman::execution::detail {
-export /* --------- */ template <::beman::execution::scope_token Token, ::beman::execution::sender Sender>
-struct associate_data {
-    using wrap_sender = ::std::remove_cvref_t<decltype(::std::declval<Token&>().wrap(::std::declval<Sender>()))>;
-
-    explicit associate_data(Token t, Sender&& s) : token(t), sender(this->token.wrap(::std::forward<Sender>(s))) {
-        if (!token.try_associate()) {
-            this->sender.reset();
-        }
-    }
-    associate_data(const associate_data& other) noexcept(::std::is_nothrow_copy_constructible_v<wrap_sender> &&
-                                                         noexcept(token.try_associate()))
-        : token(other.token), sender() {
-        if (other.sender && this->token.try_associate()) {
-            try {
-                this->sender.emplace(*other.sender);
-            } catch (...) {
-                this->token.disassociate();
-            }
-        }
-    }
-    associate_data(associate_data&& other) noexcept(::std::is_nothrow_move_constructible_v<wrap_sender>)
-        : token(other.token), sender(::std::move(other.sender)) {
-        other.sender.reset();
-    }
-    auto operator=(const associate_data&) -> associate_data& = delete;
-    auto operator=(associate_data&&) -> associate_data&      = delete;
-    ~associate_data() {
-        if (this->sender) {
-            this->sender.reset();
-            this->token.disassociate();
-        }
-    }
-#line 58 "include/beman/execution/detail/associate.hpp"
-    auto release() -> ::std::optional<::std::pair<Token, wrap_sender>> {
-        return this->sender ? (std::unique_ptr<std::optional<wrap_sender>, decltype([](auto* opt) { opt->reset(); })>(
-                                   &this->sender),
-                               ::std::optional{::std::pair{::std::move(this->token), ::std::move(*this->sender)}})
-                            : ::std::optional<::std::pair<Token, wrap_sender>>{};
-    }
-#line 65 "include/beman/execution/detail/associate.hpp"
-    Token                        token;
-    ::std::optional<wrap_sender> sender;
-};
-export /* --------- */ template <::beman::execution::scope_token Token, ::beman::execution::sender Sender>
-associate_data(Token, Sender&&) -> associate_data<Token, Sender>;
-
-struct associate_t {
-    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token>
-    auto operator()(Sender&& sender, Token&& token) const {
-        auto domain(::beman::execution::detail::get_domain_early(sender));
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this,
-                ::beman::execution::detail::associate_data(::std::forward<Token>(token),
-                                                           ::std::forward<Sender>(sender))));
-    }
-};
-
-template <>
-struct impls_for<associate_t> : ::beman::execution::detail::default_impls {
-    template <typename, typename>
-    struct get_noexcept : ::std::false_type {};
-    template <typename Tag, typename Data, typename Receiver>
-    struct get_noexcept<::beman::execution::detail::basic_sender<Tag, Data>, Receiver>
-        : ::std::bool_constant<
-              ::std::is_nothrow_move_constructible_v<typename ::std::remove_cvref_t<Data>::wrap_sender>&& ::beman::
-                  execution::detail::nothrow_callable<::beman::execution::connect_t,
-                                                      typename ::std::remove_cvref_t<Data>::wrap_sender,
-                                                      Receiver>> {};
-
-    static constexpr auto get_state =
-        []<typename Sender, typename Receiver>(Sender&& sender, Receiver& receiver) noexcept(
-            ::std::is_nothrow_constructible_v<::std::remove_cvref_t<Sender>, Sender>&&
-                get_noexcept<::std::remove_cvref_t<Sender>, Receiver>::value) {
-            auto [_, data] = ::std::forward<Sender>(sender);
-            auto dataParts{data.release()};
-
-            using scope_token = decltype(dataParts->first);
-            using wrap_sender = decltype(dataParts->second);
-            using op_t        = decltype(::beman::execution::connect(::std::move(dataParts->second),
-                                                              ::std::forward<Receiver>(receiver)));
-
-            struct op_state {
-                using sop_t        = op_t;
-                using sscope_token = scope_token;
-                struct assoc_t {
-                    sscope_token tok;
-                    sop_t        op;
-                };
-
-                bool associated{false};
-                union {
-                    Receiver* rcvr;
-                    assoc_t   assoc;
-                };
-                explicit op_state(Receiver& r) noexcept : rcvr(::std::addressof(r)) {}
-                explicit op_state(sscope_token tk, wrap_sender&& sndr, Receiver& r) try
-                    : associated(true), assoc(tk, ::beman::execution::connect(::std::move(sndr), ::std::move(r))) {
-                } catch (...) {
-                    tk.disassociate();
-                    throw;
-                }
-                op_state(op_state&&) = delete;
-                ~op_state() {
-                    if (this->associated) {
-                        this->assoc.op.~sop_t();
-                        this->assoc.tok.disassociate();
-                        this->assoc.tok.~sscope_token();
-                    }
-                }
-                auto run() noexcept -> void {
-                    if (this->associated) {
-                        ::beman::execution::start(this->assoc.op);
-                    } else {
-                        ::beman::execution::set_stopped(::std::move(*this->rcvr));
-                    }
-                }
-            };
-            return dataParts ? op_state(::std::move(dataParts->first), ::std::move(dataParts->second), receiver)
-                             : op_state(receiver);
-        };
-    static constexpr auto start = [](auto& state, auto&&) noexcept -> void { state.run(); };
-};
-
-template <typename Data, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::associate_t, Data>,
-    Env> {
-    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t()>;
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using associate_t = ::beman::execution::detail::associate_t;
-export /* --------- */ inline constexpr associate_t associate{};
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/as_awaitable.hpp"
-namespace beman::execution {
-
-#line 24 "include/beman/execution/detail/as_awaitable.hpp"
-export /* --------- */ struct as_awaitable_t {
-    template <typename Expr, typename Promise>
-    auto operator()(Expr&& expr, Promise& promise) const {
-        if constexpr (requires { ::std::forward<Expr>(expr).as_awaitable(promise); }) {
-            static_assert(
-                ::beman::execution::detail::is_awaitable<decltype(::std::forward<Expr>(expr).as_awaitable(promise)),
-                                                         Promise>,
-                "as_awaitable must return an awaitable");
-            return ::std::forward<Expr>(expr).as_awaitable(promise);
-        } else if constexpr (::beman::execution::detail::
-                                 is_awaitable<Expr, ::beman::execution::detail::unspecified_promise> ||
-                             !::beman::execution::detail::awaitable_sender<Expr, Promise>) {
-            return ::std::forward<Expr>(expr);
-        } else {
-            return ::beman::execution::detail::sender_awaitable<Expr, Promise>{::std::forward<Expr>(expr), promise};
-        }
-    }
-};
-export /* --------- */ inline constexpr ::beman::execution::as_awaitable_t as_awaitable{};
-} // namespace beman::execution
-
-#line 26 "include/beman/execution/detail/counting_scope_join.hpp"
-namespace beman::execution::detail {
-struct counting_scope_join_t {
-    template <::beman::execution::receiver>
-    struct state;
-
-    auto operator()(::beman::execution::detail::counting_scope_base* ptr) const {
-        return ::beman::execution::detail::make_sender(*this, ptr);
-    }
-};
-inline constexpr counting_scope_join_t counting_scope_join{};
-
-template <typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::counting_scope_join_t,
-                                             ::beman::execution::detail::counting_scope_base*>,
-    Env> {
-    using type = ::beman::execution::completion_signatures<::beman::execution::set_value_t()>;
-};
-
-} // namespace beman::execution::detail
-
-#line 49 "include/beman/execution/detail/counting_scope_join.hpp"
-template <::beman::execution::receiver Receiver>
-struct beman::execution::detail::counting_scope_join_t::state : ::beman::execution::detail::counting_scope_base::node {
-    using op_t = decltype(::beman::execution::connect(::beman::execution::schedule(::beman::execution::get_scheduler(
-                                                          ::beman::execution::get_env(::std::declval<Receiver&>()))),
-                                                      ::std::declval<Receiver&>()));
-
-    ::beman::execution::detail::counting_scope_base* scope;
-    explicit state(::beman::execution::detail::counting_scope_base* s, Receiver& r)
-        : scope(s),
-          receiver(r),
-          op(::beman::execution::connect(::beman::execution::schedule(::beman::execution::get_scheduler(
-                                             ::beman::execution::get_env(this->receiver))),
-                                         this->receiver)) {}
-    virtual ~state() = default;
-
-    auto complete() noexcept -> void override { ::beman::execution::start(this->op); }
-    auto complete_inline() noexcept -> void override { ::beman::execution::set_value(::std::move(this->receiver)); }
-
-    auto start() noexcept -> void { this->scope->start_node(this); }
-
-    ::std::remove_cvref_t<Receiver>& receiver;
-    op_t                             op;
-};
-
-#line 75 "include/beman/execution/detail/counting_scope_join.hpp"
-namespace beman::execution::detail {
-template <>
-struct impls_for<::beman::execution::detail::counting_scope_join_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_state = []<typename Receiver>(auto&& sender, Receiver& receiver) noexcept(false) {
-        auto [_, self] = sender;
-        return ::beman::execution::detail::counting_scope_join_t::state<Receiver>(self, receiver);
-    };
-    static constexpr auto start = [](auto& s, auto&) noexcept { s.start(); };
-};
-} // namespace beman::execution::detail
-
-#line 36 "include/beman/execution/detail/affine_on.hpp"
-namespace beman::execution::detail {
-template <typename Ev>
-struct affine_on_env {
-    Ev   ev_;
-    auto query(const ::beman::execution::get_stop_token_t&) const noexcept -> ::beman::execution::never_stop_token {
-        return ::beman::execution::never_stop_token();
-    }
-    template <typename Q>
-    auto query(const Q& q) const noexcept -> decltype(q(this->ev_)) {
-        return q(this->ev_);
-    }
-};
-template <typename Ev>
-affine_on_env(const Ev&) -> affine_on_env<Ev>;
-
-#line 59 "include/beman/execution/detail/affine_on.hpp"
-struct affine_on_t : ::beman::execution::sender_adaptor_closure<affine_on_t> {
-
-#line 67 "include/beman/execution/detail/affine_on.hpp"
-    template <::beman::execution::sender Sender>
-    auto operator()(Sender&& sender) const {
-        return ::beman::execution::detail::transform_sender(
-            ::beman::execution::detail::get_domain_early(sender),
-            ::beman::execution::detail::make_sender(
-                *this, ::beman::execution::env<>{}, ::std::forward<Sender>(sender)));
-    }
-#line 80 "include/beman/execution/detail/affine_on.hpp"
-    auto operator()() const { return ::beman::execution::detail::sender_adaptor{*this}; }
-
-#line 100 "include/beman/execution/detail/affine_on.hpp"
-    template <::beman::execution::sender Sender, typename Env>
-        requires ::beman::execution::detail::sender_for<Sender, affine_on_t> && requires(const Env& env) {
-            { ::beman::execution::get_scheduler(env) } -> ::beman::execution::scheduler;
-            { ::beman::execution::schedule(::beman::execution::get_scheduler(env)) } -> ::beman::execution::sender;
-            {
-                ::beman::execution::get_completion_signatures(
-                    ::beman::execution::schedule(::beman::execution::get_scheduler(env)),
-                    ::beman::execution::detail::join_env(
-                        ::beman::execution::env{::beman::execution::prop{
-                            ::beman::execution::get_stop_token, ::beman::execution::never_stop_token{}, {}}},
-                        env))
-            } -> ::std::same_as<::beman::execution::completion_signatures<::beman::execution::set_value_t()>>;
-        }
-    static auto transform_sender(Sender&& sender, const Env& ev) {
-        [[maybe_unused]] auto& [tag, data, child] = sender;
-        using child_tag_t = ::beman::execution::tag_of_t<::std::remove_cvref_t<decltype(child)>>;
-
-        if constexpr (::beman::execution::detail::nested_sender_has_affine_on<Sender, Env>) {
-            constexpr child_tag_t t{};
-            return t.affine_on(::beman::execution::detail::forward_like<Sender>(child), ev);
-        } else {
-            return ::beman::execution::write_env(
-                ::beman::execution::schedule_from(
-                    ::beman::execution::get_scheduler(ev),
-                    ::beman::execution::write_env(::beman::execution::detail::forward_like<Sender>(child), ev)),
-                beman::execution::detail::affine_on_env(ev));
-        }
-    }
-};
-
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-
-#line 137 "include/beman/execution/detail/affine_on.hpp"
-export /* --------- */ using affine_on_t = beman::execution::detail::affine_on_t;
-export /* --------- */ inline constexpr affine_on_t affine_on{};
-} // namespace beman::execution
-
-#line 32 "include/beman/execution/detail/continues_on.hpp"
-namespace beman::execution::detail {
-
-#line 39 "include/beman/execution/detail/continues_on.hpp"
-struct continues_on_t {
-    template <::beman::execution::detail::sender_for<continues_on_t> Sender, typename... Env>
-    static auto transform_sender(Sender&& sender, Env&&...) {
-        auto&& data{sender.template get<1>()};
-        auto&& child{sender.template get<2>()};
-        return ::beman::execution::schedule_from(std::move(data), std::move(child));
-    }
-    template <::beman::execution::scheduler Scheduler>
-    auto operator()(Scheduler&& scheduler) const {
-        return ::beman::execution::detail::sender_adaptor{*this, ::std::forward<Scheduler>(scheduler)};
-    }
-    template <::beman::execution::sender Sender, ::beman::execution::scheduler Scheduler>
-    auto operator()(Sender&& sender, Scheduler&& scheduler) const {
-        auto domain(::beman::execution::detail::get_domain_early(sender));
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this, std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
-    }
-};
-
-#line 65 "include/beman/execution/detail/continues_on.hpp"
-template <>
-struct impls_for<::beman::execution::detail::continues_on_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto get_attrs{[](const auto& data, const auto& child) noexcept -> decltype(auto) {
-        return ::beman::execution::detail::join_env(
-            ::beman::execution::detail::sched_attrs(data),
-            ::beman::execution::detail::fwd_env(::beman::execution::get_env(child)));
-    }};
-};
-
-#line 79 "include/beman/execution/detail/continues_on.hpp"
-template <::beman::execution::detail::sender_for<::beman::execution::detail::continues_on_t> Sender, typename Env>
-auto get_domain_late(Sender&& sender, Env&&) {
-    auto scheduler{sender.template get<1>()};
-    return ::beman::execution::detail::query_with_default(
-        ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{});
-}
-} // namespace beman::execution::detail
-
-#line 89 "include/beman/execution/detail/continues_on.hpp"
-namespace beman::execution {
-export /* --------- */ using continues_on_t = ::beman::execution::detail::continues_on_t;
-
-#line 95 "include/beman/execution/detail/continues_on.hpp"
-export /* --------- */ inline constexpr continues_on_t continues_on{};
-} // namespace beman::execution
-
-#line 26 "include/beman/execution/detail/starts_on.hpp"
-namespace beman::execution::detail {
-struct starts_on_t {
-    template <::beman::execution::detail::sender_for<::beman::execution::detail::starts_on_t> Sender, typename Env>
-    auto transform_env(Sender&& sender, Env&& env) const noexcept {
-        auto&& scheduler{sender.template get<1>()};
-        return ::beman::execution::detail::join_env(::beman::execution::detail::sched_env(scheduler),
-                                                    ::beman::execution::detail::fwd_env(env));
-    }
-    template <::beman::execution::detail::sender_for<::beman::execution::detail::starts_on_t> Sender, typename... Env>
-    auto transform_sender(Sender&& sender, Env&&...) const noexcept {
-        auto&& scheduler{sender.template get<1>()};
-        auto&& new_sender{sender.template get<2>()};
-        return ::beman::execution::let_value(
-            ::beman::execution::schedule(scheduler),
-            [new_sender = ::beman::execution::detail::forward_like<Sender>(new_sender)]() mutable noexcept(
-                ::std::is_nothrow_constructible_v<::std::decay_t<Sender>>) { return ::std::move(new_sender); });
-    }
-#line 44 "include/beman/execution/detail/starts_on.hpp"
-    template <::beman::execution::scheduler Scheduler, ::beman::execution::sender Sender>
-    auto operator()(Scheduler&& scheduler, Sender&& sender) const {
-        auto domain{::beman::execution::detail::query_with_default(
-            ::beman::execution::get_domain, scheduler, ::beman::execution::default_domain{})};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this, ::std::forward<Scheduler>(scheduler), ::std::forward<Sender>(sender)));
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using starts_on_t = ::beman::execution::detail::starts_on_t;
-export /* --------- */ inline constexpr ::beman::execution::detail::starts_on_t starts_on{};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/when_all_with_variant.hpp"
-namespace beman::execution::detail {
-struct when_all_with_variant_t {
-
-    template <::beman::execution::sender Sender>
-    auto transform_sender(Sender&& sender, auto&&...) const noexcept {
-        return ::std::forward<Sender>(sender).apply([](auto&&, auto&&, auto&&... child) {
-            return ::beman::execution::when_all(
-                ::beman::execution::into_variant(::beman::execution::detail::forward_like<Sender>(child))...);
-        });
-    }
-#line 33 "include/beman/execution/detail/when_all_with_variant.hpp"
-    template <::beman::execution::sender... Sender>
-    auto operator()(Sender&&... sender) const {
-        using domain_t =
-            typename ::std::common_type_t<decltype(::beman::execution::detail::get_domain_early(sender))...>;
-        return ::beman::execution::transform_sender(
-            domain_t{}, ::beman::execution::detail::make_sender(*this, {}, ::std::forward<Sender>(sender)...));
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using when_all_with_variant_t = ::beman::execution::detail::when_all_with_variant_t;
-export /* --------- */ inline constexpr ::beman::execution::when_all_with_variant_t when_all_with_variant{};
-} // namespace beman::execution
-
-#line 14 "include/beman/execution/detail/with_awaitable_senders.hpp"
-namespace beman::execution {
-export /* --------- */ template <::beman::execution::detail::class_type Promise>
-struct with_awaitable_senders {
-    template <class OtherPromise>
-        requires(!::std::same_as<OtherPromise, void>)
-    void set_continuation(::std::coroutine_handle<OtherPromise> h) noexcept {
-        contination_ = h;
-        if constexpr (requires(OtherPromise& other) { other.unhandled_stopped(); }) {
-            stopped_handler_ = [](void* p) noexcept -> ::std::coroutine_handle<> {
-                return ::std::coroutine_handle<OtherPromise>::from_address(p).promise().unhandled_stopped();
-            };
-        } else {
-            stopped_handler_ = &default_unhandled_stopped;
-        }
-    }
-#line 30 "include/beman/execution/detail/with_awaitable_senders.hpp"
-    ::std::coroutine_handle<> continuation() const noexcept { return contination_; }
-
-    ::std::coroutine_handle<> unhandled_stopped() noexcept { return stopped_handler_(contination_.address()); }
-
-    template <class Value>
-    auto await_transform(Value&& value)
-        -> ::beman::execution::detail::call_result_t<::beman::execution::as_awaitable_t, Value, Promise&> {
-        return ::beman::execution::as_awaitable(::std::forward<Value>(value), static_cast<Promise&>(*this));
-    }
-#line 40 "include/beman/execution/detail/with_awaitable_senders.hpp"
-  private:
-    friend Promise;
-    with_awaitable_senders() = default;
-
-    [[noreturn]] static auto default_unhandled_stopped(void*) noexcept -> ::std::coroutine_handle<> {
-        ::std::terminate();
-    }
-#line 48 "include/beman/execution/detail/with_awaitable_senders.hpp"
-    ::std::coroutine_handle<> contination_{};
-    ::std::coroutine_handle<> (*stopped_handler_)(void*) noexcept = &default_unhandled_stopped;
-};
-
-} // namespace beman::execution
-
-#line 19 "include/beman/execution/detail/counting_scope.hpp"
-namespace beman::execution {
-export /* --------- */ class counting_scope;
-}
-#line 25 "include/beman/execution/detail/counting_scope.hpp"
-class beman::execution::counting_scope : public ::beman::execution::detail::counting_scope_base {
-  public:
-    class token;
-
-    auto join() noexcept -> ::beman::execution::sender auto {
-        return ::beman::execution::detail::counting_scope_join(this);
-    }
-    auto get_token() noexcept -> token;
-    auto request_stop() noexcept -> void { this->stop_source.request_stop(); }
-
-  private:
-    ::beman::execution::inplace_stop_source stop_source{};
-};
-
-#line 41 "include/beman/execution/detail/counting_scope.hpp"
-class beman::execution::counting_scope::token : public ::beman::execution::detail::counting_scope_base::token {
-  public:
-    template <::beman::execution::sender Sender>
-    auto wrap(Sender&& sender) const noexcept -> ::beman::execution::sender auto {
-        return ::beman::execution::detail::stop_when(
-            ::std::forward<Sender>(sender),
-            static_cast<::beman::execution::counting_scope*>(this->scope)->stop_source.get_token());
-    }
-#line 50 "include/beman/execution/detail/counting_scope.hpp"
-  private:
-    friend class beman::execution::counting_scope;
-    explicit token(::beman::execution::counting_scope* s)
-        : ::beman::execution::detail::counting_scope_base::token(s) {}
-};
-static_assert(::beman::execution::scope_token<::beman::execution::counting_scope::token>);
-
-#line 59 "include/beman/execution/detail/counting_scope.hpp"
-inline auto beman::execution::counting_scope::get_token() noexcept -> beman::execution::counting_scope::token {
-    return beman::execution::counting_scope::token(this);
-}
-#line 16 "include/beman/execution/detail/simple_counting_scope.hpp"
-namespace beman::execution {
-export /* --------- */ class simple_counting_scope;
-}
-#line 22 "include/beman/execution/detail/simple_counting_scope.hpp"
-class beman::execution::simple_counting_scope : public ::beman::execution::detail::counting_scope_base {
-  public:
-    class token;
-
-    auto get_token() noexcept -> token;
-    auto join() noexcept -> ::beman::execution::sender auto {
-        return ::beman::execution::detail::counting_scope_join(this);
-    }
-};
-
-#line 34 "include/beman/execution/detail/simple_counting_scope.hpp"
-class beman::execution::simple_counting_scope::token : public ::beman::execution::detail::counting_scope_base::token {
-  public:
-    template <::beman::execution::sender Sender>
-    auto wrap(Sender&& sender) const noexcept -> Sender&& {
-        return ::std::forward<Sender>(sender);
-    }
-#line 41 "include/beman/execution/detail/simple_counting_scope.hpp"
-  private:
-    friend class beman::execution::simple_counting_scope;
-    explicit token(::beman::execution::detail::counting_scope_base* s)
-        : ::beman::execution::detail::counting_scope_base::token(s) {}
-};
-
-#line 49 "include/beman/execution/detail/simple_counting_scope.hpp"
-inline auto beman::execution::simple_counting_scope::get_token() noexcept
-    -> beman::execution::simple_counting_scope::token {
-    return beman::execution::simple_counting_scope::token(this);
-}
-#line 44 "include/beman/execution/detail/spawn_future.hpp"
-namespace beman::execution::detail {
-template <typename>
-struct non_throwing_args_copy;
-template <typename Rc, typename... A>
-struct non_throwing_args_copy<Rc(A...)> {
-    static constexpr bool value = (true && ... && ::std::is_nothrow_constructible_v<::std::decay_t<A>, A>);
-};
-template <typename S>
-inline constexpr bool non_throwing_args_copy_v{non_throwing_args_copy<S>::value};
-
-template <typename Completions>
-struct spawn_future_state_base;
-template <typename... Sigs>
-struct spawn_future_state_base<::beman::execution::completion_signatures<Sigs...>> {
-    static constexpr bool has_non_throwing_args_copy = (true && ... && non_throwing_args_copy_v<Sigs>);
-    using result_t                                   = ::beman::execution::detail::meta::unique<
-                                          ::std::conditional_t<has_non_throwing_args_copy,
-                                                               ::std::variant<::std::monostate, ::beman::execution::detail::as_tuple_t<Sigs>...>,
-                                                               ::std::variant<::std::monostate,
-                                                                              ::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>,
-                                                                              ::beman::execution::detail::as_tuple_t<Sigs>...>>>;
-
-    result_t result{};
-    virtual ~spawn_future_state_base()       = default;
-    virtual auto complete() noexcept -> void = 0;
-};
-
-template <typename Completions>
-struct spawn_future_receiver {
-    using receiver_concept = ::beman::execution::receiver_t;
-    using state_t          = ::beman::execution::detail::spawn_future_state_base<Completions>;
-
-    state_t* state{};
-
-    template <typename... A>
-    auto set_value(A&&... a) && noexcept -> void {
-        this->set_complete<::beman::execution::set_value_t>(::std::forward<A>(a)...);
-    }
-    template <typename E>
-    auto set_error(E&& e) && noexcept -> void {
-        this->set_complete<::beman::execution::set_error_t>(::std::forward<E>(e));
-    }
-    auto set_stopped() && noexcept -> void { this->set_complete<::beman::execution::set_stopped_t>(); }
-
-    template <typename Tag, typename... T>
-    auto set_complete(T&&... t) noexcept {
-        try {
-            this->state->result.template emplace<::beman::execution::detail::decayed_tuple<Tag, T...>>(
-                Tag(), ::std::forward<T>(t)...);
-        } catch (...) {
-            if constexpr (!state_t::has_non_throwing_args_copy) {
-                this->state->result
-                    .template emplace<::std::tuple<::beman::execution::set_error_t, ::std::exception_ptr>>(
-                        ::beman::execution::set_error_t{}, ::std::current_exception());
-            }
-        }
-        this->state->complete();
-    }
-};
-
-template <::beman::execution::sender Sndr, typename Env>
-using future_spawned_sender = decltype(::beman::execution::write_env(
-    ::beman::execution::detail::stop_when(::std::declval<Sndr>(),
-                                          ::std::declval<::beman::execution::inplace_stop_token>()),
-    ::std::declval<Env>()));
-
-template <::beman::execution::sender Sndr, typename Env>
-using spawn_future_sigs = ::beman::execution::detail::meta::unique<::beman::execution::detail::meta::prepend<
-    ::beman::execution::set_stopped_t(),
-    ::beman::execution::completion_signatures_of_t<::beman::execution::detail::future_spawned_sender<Sndr, Env>>>>;
-
-template <typename Allocator, ::beman::execution::scope_token Token, ::beman::execution::sender Sndr, typename Env>
-struct spawn_future_state
-    : ::beman::execution::detail::spawn_future_state_base<::beman::execution::detail::spawn_future_sigs<Sndr, Env>> {
-    using alloc_t          = typename ::std::allocator_traits<Allocator>::template rebind_alloc<spawn_future_state>;
-    using traits_t         = ::std::allocator_traits<alloc_t>;
-    using spawned_sender_t = ::beman::execution::detail::future_spawned_sender<Sndr, Env>;
-    using sigs_t           = ::beman::execution::detail::spawn_future_sigs<Sndr, Env>;
-    using receiver_t       = ::beman::execution::detail::spawn_future_receiver<sigs_t>;
-    static_assert(::beman::execution::sender<spawned_sender_t>);
-    static_assert(::beman::execution::receiver<receiver_t>);
-    using op_t = ::beman::execution::connect_result_t<spawned_sender_t, receiver_t>;
-
-    template <::beman::execution::sender S>
-    spawn_future_state(auto a, S&& s, Token tok, Env env)
-        : alloc(::std::move(a)),
-          op(::beman::execution::write_env(
-                 ::beman::execution::detail::stop_when(::std::forward<S>(s), source.get_token()), env),
-             receiver_t{this}),
-          token(::std::move(tok)),
-          associated(token.try_associate()) {
-        if (this->associated) {
-            ::beman::execution::start(this->op);
-        } else {
-            ::beman::execution::set_stopped(receiver_t{this});
-        }
-    }
-    auto complete() noexcept -> void override {
-        {
-            ::std::lock_guard cerberos(this->gate);
-            if (this->fun == nullptr) {
-                this->receiver = this;
-                return;
-            }
-        }
-        this->fun(this->receiver, *this);
-    }
-    auto abandon() noexcept -> void {
-        bool ready{[&] {
-            ::std::lock_guard cerberos(this->gate);
-            if (this->receiver == nullptr) {
-                this->receiver = this;
-                this->fun      = [](void*, spawn_future_state& state) noexcept { state.destroy(); };
-                return false;
-            }
-            return true;
-        }()};
-        if (ready) {
-            this->destroy();
-        } else {
-            this->source.request_stop();
-        }
-    }
-    template <::beman::execution::receiver Rcvr>
-    static auto complete_receiver(Rcvr& rcvr, typename spawn_future_state::result_t& res) noexcept {
-        std::visit(
-            [&rcvr]<typename Tuplish>(Tuplish&& tuplish) noexcept {
-                if constexpr (!::std::same_as<::std::remove_cvref_t<decltype(tuplish)>, ::std::monostate>) {
-                    ::std::apply(
-                        [&rcvr]<typename... Args>(auto cpo, Args&&... args) {
-                            cpo(::std::move(rcvr), ::std::forward<Args>(args)...);
-                        },
-                        ::std::forward<Tuplish>(tuplish));
-                }
-            },
-            ::std::move(res));
-    }
-    template <::beman::execution::receiver Rcvr>
-    auto consume(Rcvr& rcvr) noexcept -> void {
-        {
-            ::std::lock_guard cerberos(this->gate);
-            if (this->receiver == nullptr) {
-                this->receiver = &rcvr;
-                this->fun      = [](void* ptr, spawn_future_state& state) noexcept {
-                    spawn_future_state::complete_receiver(*static_cast<Rcvr*>(ptr), state.result);
-                };
-                return;
-            }
-        }
-        spawn_future_state::complete_receiver(rcvr, this->result);
-    }
-    auto destroy() noexcept -> void {
-        Token tok{this->token};
-        bool  assoc{this->associated};
-        {
-            alloc_t a{this->alloc};
-            traits_t::destroy(a, this);
-            traits_t::deallocate(a, this, 1u);
-        }
-        if (assoc) {
-            tok.disassociate();
-        }
-    }
-#line 208 "include/beman/execution/detail/spawn_future.hpp"
-    ::std::mutex                            gate{};
-    alloc_t                                 alloc;
-    ::beman::execution::inplace_stop_source source{};
-    op_t                                    op;
-    Token                                   token;
-    bool                                    associated{false};
-    void*                                   receiver{};
-    auto (*fun)(void*, spawn_future_state&) noexcept -> void = nullptr;
-};
-
-class spawn_future_t {
-  public:
-    template <::beman::execution::sender Sndr, ::beman::execution::scope_token Tok, typename Ev>
-        requires ::beman::execution::detail::queryable<::std::remove_cvref_t<Ev>>
-    auto operator()(Sndr&& sndr, Tok&& tok, Ev&& ev) const {
-
-        auto make{[&]() -> decltype(auto) { return tok.wrap(::std::forward<Sndr>(sndr)); }};
-        using sndr_t = decltype(make());
-        static_assert(::beman::execution::sender<Sndr>);
-
-        auto [alloc, senv] = spawn_get_allocator(sndr, ev);
-        using state_t = ::beman::execution::detail::spawn_future_state<decltype(alloc), Tok, sndr_t, decltype(senv)>;
-        using state_alloc_t  = typename ::std::allocator_traits<decltype(alloc)>::template rebind_alloc<state_t>;
-        using state_traits_t = ::std::allocator_traits<state_alloc_t>;
-        state_alloc_t state_alloc(alloc);
-        state_t*      op{state_traits_t::allocate(state_alloc, 1u)};
-        try {
-            state_traits_t::construct(state_alloc, op, alloc, make(), tok, senv);
-        } catch (...) {
-            state_traits_t::deallocate(state_alloc, op, 1u);
-            throw;
-        }
-#line 241 "include/beman/execution/detail/spawn_future.hpp"
-        using deleter = decltype([](state_t* p) noexcept { p->abandon(); });
-        return ::beman::execution::detail::make_sender(*this, ::std::unique_ptr<state_t, deleter>{op});
-    }
-    template <::beman::execution::sender Sndr, ::beman::execution::scope_token Tok>
-    auto operator()(Sndr&& sndr, Tok&& tok) const {
-        return (*this)(::std::forward<Sndr>(sndr), ::std::forward<Tok>(tok), ::beman::execution::env<>{});
-    }
-};
-
-template <typename State, typename Deleter, typename Env>
-struct completion_signatures_for_impl<
-    ::beman::execution::detail::basic_sender<::beman::execution::detail::spawn_future_t,
-                                             ::std::unique_ptr<State, Deleter>>,
-    Env> {
-    using type = typename State::sigs_t;
-};
-
-template <>
-struct impls_for<spawn_future_t> : ::beman::execution::detail::default_impls {
-    static constexpr auto start{[](auto& state, auto& rcvr) noexcept -> void { state->consume(rcvr); }};
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using spawn_future_t = ::beman::execution::detail::spawn_future_t;
-export /* --------- */ inline constexpr spawn_future_t spawn_future{};
-} // namespace beman::execution
-
-#line 22 "include/beman/execution/detail/spawn.hpp"
-namespace beman::execution::detail {
-struct spawn_t {
-    struct state_base {
-        virtual ~state_base()                    = default;
-        virtual auto complete() noexcept -> void = 0;
-    };
-
-    struct receiver {
-        using receiver_concept = ::beman::execution::receiver_t;
-        state_base* state{};
-
-        auto set_value() && noexcept -> void { this->state->complete(); }
-        auto set_stopped() && noexcept -> void { this->state->complete(); }
-    };
-
-    template <typename Alloc, ::beman::execution::scope_token Tok, ::beman::execution::sender Sndr>
-    struct state : state_base {
-        using op_t     = ::beman::execution::connect_result_t<Sndr, receiver>;
-        using alloc_t  = typename ::std::allocator_traits<Alloc>::template rebind_alloc<state>;
-        using traits_t = ::std::allocator_traits<alloc_t>;
-
-        state(Alloc a, Sndr&& sndr, Tok tok)
-            : alloc(a), op(::beman::execution::connect(::std::forward<Sndr>(sndr), receiver{this})), token(tok) {
-            if (this->token.try_associate()) {
-                ::beman::execution::start(this->op);
-            } else {
-                this->destroy();
-            }
-        }
-        auto complete() noexcept -> void override {
-            Tok tok(this->token);
-            this->destroy();
-            tok.disassociate();
-        }
-        auto destroy() noexcept -> void {
-            alloc_t all(this->alloc);
-            traits_t::destroy(all, this);
-            traits_t::deallocate(all, this, 1);
-        }
-#line 62 "include/beman/execution/detail/spawn.hpp"
-        alloc_t alloc;
-        op_t    op;
-        Tok     token;
-    };
-
-    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token, typename Env>
-    auto operator()(Sender&& sender, Token&& tok, Env&& env) const {
-        auto new_sender{tok.wrap(::std::forward<Sender>(sender))};
-        auto [all, senv] = ::beman::execution::detail::spawn_get_allocator(new_sender, env);
-
-        using sender_t = decltype(::beman::execution::write_env(::std::move(new_sender), senv));
-        using state_t  = state<decltype(all), Token, sender_t>;
-        using alloc_t  = typename ::std::allocator_traits<decltype(all)>::template rebind_alloc<state_t>;
-        using traits_t = ::std::allocator_traits<alloc_t>;
-        alloc_t  alloc(all);
-        state_t* op{traits_t::allocate(alloc, 1u)};
-        traits_t::construct(alloc, op, all, ::beman::execution::write_env(::std::move(new_sender), senv), tok);
-    }
-    template <::beman::execution::sender Sender, ::beman::execution::scope_token Token>
-    auto operator()(Sender&& sender, Token&& token) const {
-        return (*this)(::std::forward<Sender>(sender), ::std::forward<Token>(token), ::beman::execution::env<>{});
-    }
-};
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using spawn_t = ::beman::execution::detail::spawn_t;
-export /* --------- */ inline constexpr spawn_t spawn{};
-} // namespace beman::execution
-
-#line 32 "include/beman/execution/detail/on.hpp"
-namespace beman::execution::detail {
-struct on_t : ::beman::execution::sender_adaptor_closure<on_t> {
-    template <::beman::execution::detail::sender_for<on_t> OutSndr, typename Env>
-    auto transform_env(OutSndr&& out_sndr, Env&& env) const -> decltype(auto) {
-        auto&& data{out_sndr.template get<1>()};
-
-        if constexpr (::beman::execution::scheduler<decltype(data)>)
-            return ::beman::execution::detail::join_env(
-                ::beman::execution::detail::sched_env(::beman::execution::detail::forward_like<OutSndr>(data)
-
-                                                          ),
-                ::beman::execution::detail::fwd_env(::std::forward<Env>(env)));
-        else
-            return std::forward<Env>(env);
-    }
-#line 48 "include/beman/execution/detail/on.hpp"
-    template <typename>
-    struct env_needs_get_scheduler {
-        using sender_concept = ::beman::execution::sender_t;
-        template <typename Env>
-        auto get_completion_signatures(Env&&) const {
-            return env_needs_get_scheduler<Env>{};
-        }
-    };
-
-    template <::beman::execution::detail::sender_for<on_t> OutSndr, typename Env>
-    auto transform_sender(OutSndr&& out_sndr, Env&& env) const -> decltype(auto) {
-        struct not_a_scheduler {};
-        auto&& [_, data, child] = out_sndr;
-
-        if constexpr (::beman::execution::scheduler<decltype(data)>) {
-            auto sch{::beman::execution::detail::query_with_default(
-                ::beman::execution::get_scheduler, env, not_a_scheduler{})};
-            if constexpr (::std::same_as<not_a_scheduler, decltype(sch)>) {
-                return env_needs_get_scheduler<Env>{};
-            } else {
-                return ::beman::execution::continues_on(
-                    ::beman::execution::starts_on(::beman::execution::detail::forward_like<OutSndr>(data),
-                                                  ::beman::execution::detail::forward_like<OutSndr>(child)),
-                    ::std::move(sch));
-            }
-        } else {
-            auto& [sch, closure] = data;
-            auto orig_sch{::beman::execution::detail::query_with_default(
-                ::beman::execution::get_completion_scheduler<::beman::execution::set_value_t>,
-                ::beman::execution::get_env(child),
-                ::beman::execution::detail::query_with_default(
-                    ::beman::execution::get_scheduler, env, not_a_scheduler{}))};
-
-            if constexpr (::std::same_as<not_a_scheduler, decltype(orig_sch)>) {
-                return env_needs_get_scheduler<Env>{};
-            } else {
-                return ::beman::execution::detail::write_env(
-                    ::beman::execution::continues_on(
-                        ::beman::execution::detail::forward_like<OutSndr>(closure)(::beman::execution::continues_on(
-                            ::beman::execution::detail::write_env(
-                                ::beman::execution::detail::forward_like<OutSndr>(child),
-                                ::beman::execution::detail::sched_env(orig_sch)),
-                            sch)),
-                        orig_sch),
-                    ::beman::execution::detail::sched_env(env));
-            }
-        }
-    }
-#line 97 "include/beman/execution/detail/on.hpp"
-    template <::beman::execution::scheduler Sch, ::beman::execution::sender Sndr>
-        requires ::beman::execution::detail::is_sender_adaptor_closure<Sndr>
-    auto operator()(Sch&&, Sndr&&) const -> void =
-        BEMAN_EXECUTION_DELETE("on(sch, sndr) requires that sndr isn't both a sender and sender adaptor closure");
-
-    template <::beman::execution::scheduler                         Sch,
-              ::beman::execution::sender                            Sndr,
-              ::beman::execution::detail::is_sender_adaptor_closure Closure>
-        requires ::beman::execution::detail::is_sender_adaptor_closure<Sndr>
-    auto operator()(Sndr&&, Sch&&, Closure&&) const -> void =
-        BEMAN_EXECUTION_DELETE("on(sch, sndr) requires that sndr isn't both a sender and sender adaptor closure");
-
-    template <::beman::execution::scheduler Sch, ::beman::execution::sender Sndr>
-    auto operator()(Sch&& sch, Sndr&& sndr) const {
-        auto domain{::beman::execution::detail::query_with_default(
-            ::beman::execution::get_domain, sch, ::beman::execution::default_domain{})};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(*this, ::std::forward<Sch>(sch), ::std::forward<Sndr>(sndr)));
-    }
-    template <::beman::execution::scheduler                         Sch,
-              ::beman::execution::sender                            Sndr,
-              ::beman::execution::detail::is_sender_adaptor_closure Closure>
-    auto operator()(Sndr&& sndr, Sch&& sch, Closure&& closure) const {
-        auto domain{::beman::execution::detail::get_domain_early(sndr)};
-        return ::beman::execution::transform_sender(
-            domain,
-            ::beman::execution::detail::make_sender(
-                *this,
-                ::beman::execution::detail::product_type{::std::forward<Sch>(sch), ::std::forward<Closure>(closure)},
-                ::std::forward<Sndr>(sndr)));
-    }
-    template <::beman::execution::scheduler Sch, ::beman::execution::detail::is_sender_adaptor_closure Closure>
-    auto operator()(Sch&& sch, Closure&& closure) const {
-        return ::beman::execution::detail::sender_adaptor{
-            *this, ::std::forward<Sch>(sch), ::std::forward<Closure>(closure)};
-    }
-};
-
-} // namespace beman::execution::detail
-
-namespace beman::execution {
-export /* --------- */ using on_t = ::beman::execution::detail::on_t;
-export /* --------- */ inline constexpr ::beman::execution::on_t on{};
-} // namespace beman::execution
diff --git a/tests/beman/execution/exec-scope-counting.test.cpp b/tests/beman/execution/exec-scope-counting.test.cpp
index c5438a98..19ed7ba0 100644
--- a/tests/beman/execution/exec-scope-counting.test.cpp
+++ b/tests/beman/execution/exec-scope-counting.test.cpp
@@ -5,6 +5,7 @@
 #include <concepts>
 #include <tuple>
 #include <type_traits>
+#include <test/inline_scheduler.hpp>
 #ifdef BEMAN_HAS_MODULES
 import beman.execution;
 #else
@@ -13,7 +14,6 @@ import beman.execution;
 #include <beman/execution/detail/just.hpp>
 #include <beman/execution/detail/sync_wait.hpp>
 #endif
-#include <test/inline_scheduler.hpp>
 
 // ----------------------------------------------------------------------------
 
diff --git a/tests/beman/execution/exec-scope-simple-counting.test.cpp b/tests/beman/execution/exec-scope-simple-counting.test.cpp
index f55b0fd4..bc89a175 100644
--- a/tests/beman/execution/exec-scope-simple-counting.test.cpp
+++ b/tests/beman/execution/exec-scope-simple-counting.test.cpp
@@ -5,6 +5,7 @@
 #include <concepts>
 #include <tuple>
 #include <type_traits>
+#include <test/inline_scheduler.hpp>
 #ifdef BEMAN_HAS_MODULES
 import beman.execution;
 #else
@@ -13,7 +14,6 @@ import beman.execution;
 #include <beman/execution/detail/just.hpp>
 #include <beman/execution/detail/sync_wait.hpp>
 #endif
-#include <test/inline_scheduler.hpp>
 
 // ----------------------------------------------------------------------------
 
diff --git a/tests/beman/execution/include/test/inline_scheduler.hpp b/tests/beman/execution/include/test/inline_scheduler.hpp
index b6d133cc..e9ab32e5 100644
--- a/tests/beman/execution/include/test/inline_scheduler.hpp
+++ b/tests/beman/execution/include/test/inline_scheduler.hpp
@@ -4,7 +4,10 @@
 #ifndef INCLUDED_TESTS_BEMAN_EXECUTION_INCLUDE_TEST_INLINE_SCHEDULER
 #define INCLUDED_TESTS_BEMAN_EXECUTION_INCLUDE_TEST_INLINE_SCHEDULER
 
-#if 0
+#include <test/execution.hpp>
+#ifdef BEMAN_HAS_MODULES
+import beman.execution;
+#else
 #include <beman/execution/detail/get_completion_scheduler.hpp>
 #include <beman/execution/detail/get_env.hpp>
 #include <beman/execution/detail/sender.hpp>
@@ -13,7 +16,6 @@
 #include <beman/execution/detail/operation_state.hpp>
 #include <beman/execution/detail/scheduler.hpp>
 #include <beman/execution/detail/completion_signatures.hpp>
-#include <test/execution.hpp>
 #endif
 
 // ----------------------------------------------------------------------------
diff --git a/tests/beman/execution/include/test/stop_token.hpp b/tests/beman/execution/include/test/stop_token.hpp
index 87b8eb50..8c64f866 100644
--- a/tests/beman/execution/include/test/stop_token.hpp
+++ b/tests/beman/execution/include/test/stop_token.hpp
@@ -6,7 +6,7 @@
 #define INCLUDED_TEST_STOP_TOKEN
 
 #include <beman/execution/detail/immovable.hpp>
-#include <test/execution.hpp>
+#include <beman/execution/detail/stoppable_source.hpp>
 
 #include <algorithm>
 #include <array>
@@ -20,7 +20,8 @@
 #include <mutex>
 #include <ranges>
 #include <thread>
-#if false && defined(BEMAN_HAS_MODULES) //-dk:TODO module disabled
+#include <test/execution.hpp>
+#if defined(BEMAN_HAS_MODULES)
 import beman.execution;
 #else
 #include <beman/execution/stop_token.hpp>
diff --git a/tests/beman/execution/stopsource-general.test.cpp b/tests/beman/execution/stopsource-general.test.cpp
index 845c4079..2674b182 100644
--- a/tests/beman/execution/stopsource-general.test.cpp
+++ b/tests/beman/execution/stopsource-general.test.cpp
@@ -1,10 +1,9 @@
 // src/beman/execution/tests/stopsource-general.test.cpp
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include <test/execution.hpp>
-#include <test/stop_token.hpp>
 #include <cassert>
-#if false && defined(BEMAN_HAS_MODULES) //-dk:TODO module disabled
+#include <test/stop_token.hpp>
+#if defined(BEMAN_HAS_MODULES)
 import beman.execution;
 #else
 #include <beman/execution/stop_token.hpp>
diff --git a/tests/beman/execution/stopsource-inplace-general.test.cpp b/tests/beman/execution/stopsource-inplace-general.test.cpp
index 3e8dfa67..54cb4251 100644
--- a/tests/beman/execution/stopsource-inplace-general.test.cpp
+++ b/tests/beman/execution/stopsource-inplace-general.test.cpp
@@ -1,9 +1,8 @@
 // src/beman/execution/tests/stopsource-inplace-general.test.cpp
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include <test/execution.hpp>
 #include <test/stop_token.hpp>
-#if false && defined(BEMAN_HAS_MODULES) //-dk:TODO module disabled
+#if defined(BEMAN_HAS_MODULES) //-dk:TODO module disabled
 import beman.execution;
 #else
 #include <beman/execution/stop_token.hpp>
diff --git a/tests/beman/execution/stoptoken-general.test.cpp b/tests/beman/execution/stoptoken-general.test.cpp
index aa89d74f..d997a5bc 100644
--- a/tests/beman/execution/stoptoken-general.test.cpp
+++ b/tests/beman/execution/stoptoken-general.test.cpp
@@ -1,9 +1,8 @@
 // src/beman/execution/tests/stoptoken-general.test.cpp
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include <test/execution.hpp>
 #include <test/stop_token.hpp>
-#if false && defined(BEMAN_HAS_MODULES) //-dk:TODO module disabled
+#if defined(BEMAN_HAS_MODULES) //-dk:TODO module disabled
 import beman.execution;
 #else
 #include <beman/execution/stop_token.hpp>
diff --git a/tests/beman/execution/stoptoken-mem.test.cpp b/tests/beman/execution/stoptoken-mem.test.cpp
index 8842756f..4f4006e1 100644
--- a/tests/beman/execution/stoptoken-mem.test.cpp
+++ b/tests/beman/execution/stoptoken-mem.test.cpp
@@ -3,9 +3,8 @@
 
 #include <array>
 #include <memory>
-#include <test/execution.hpp>
 #include <test/stop_token.hpp>
-#if false && defined(BEMAN_HAS_MODULES) //-dk:TODO module disabled
+#if defined(BEMAN_HAS_MODULES)
 import beman.execution;
 #else
 #include <beman/execution/stop_token.hpp>
diff --git a/tests/beman/execution/thread-stoptoken-intro.test.cpp b/tests/beman/execution/thread-stoptoken-intro.test.cpp
index 198c769b..bf94531e 100644
--- a/tests/beman/execution/thread-stoptoken-intro.test.cpp
+++ b/tests/beman/execution/thread-stoptoken-intro.test.cpp
@@ -2,10 +2,9 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 #include <beman/execution/detail/immovable.hpp>
-#include <test/execution.hpp>
-#include <test/stop_token.hpp>
 #include <utility>
-#if false && defined(BEMAN_HAS_MODULES) //-dk:TODO module disabled
+#include <test/stop_token.hpp>
+#if defined(BEMAN_HAS_MODULES)
 import beman.execution;
 #else
 #include <beman/execution/stop_token.hpp>

From 936dbdad3286de20747fab1cb0cbfa911b812709 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Thu, 5 Feb 2026 23:23:04 +0000
Subject: [PATCH 6/9] fix typos

---
 docs/modules.md | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/docs/modules.md b/docs/modules.md
index 0aefed80..3ea663e8 100644
--- a/docs/modules.md
+++ b/docs/modules.md
@@ -5,7 +5,7 @@ Author: Dietmar Kühl dietmar.kuehl@me.com
 Originally [`beman.execution`](https://github.com/bemanproject/execution)
 was implemented with out `module` support. Eventually, `module`
 support in all compilers and in [`cmake`](https://cmake.org/) made
-it reaonable to add `module` support. This document describes some
+it reasonable to add `module` support. This document describes some
 of the experiences of the journey adding `module` support for
 [`beman.execution`](https://github.com/bemanproject/execution). It is
 likely that my attempts on how to support `module`s were misguided and
@@ -20,7 +20,7 @@ implementation which had no `module` support. It had tests and some
 examples and the `CMakeLists.txt` built these. The default build
 procedure run from the `Makefile` was already set up to use `ninja`.
 
-Claus Klein had started to land `cmake` support fo `module`s. In
+Claus Klein had started to land `cmake` support of `module`s. In
 particular there were `cmake` rules to detect whether there is a
 dependency scanner and whether `import std;` is supported. The
 statement from Claus was that using `import std;` would be the
@@ -56,7 +56,7 @@ it.  I tried it. There were a bunch of errors which I could work
 out easily but eventually I got stuck with unscruitible errors.
 Since I never planned to write about the experience I don't recall
 what the errors were.  When I asked about it the message was that
-neither `cmake` nor the compilers are quite there. So I abondoned
+neither `cmake` nor the compilers are quite there. So I abandoned
 this first attempt.
 
 Time passed and in the beginning of 2026 some `cmake` support for
@@ -131,7 +131,7 @@ compilers:
 </ol>
 
 To still achieve the objective of `export`ing a name when it first
-gets declared, the structure needs to be change. However, the componets
+gets declared, the structure needs to be changed. However, the components
 are organized in a consistent structure. So the idea is to use this structure
 to reorganize the files for `module` builds:
 
@@ -230,7 +230,7 @@ template and the relevant `tuple_size` and `tuple_element`
 specializations I could resolve this problem, too.
 
 Once I got past that I encountered a problem which is probably quite
-common: following the specificaton of exposition-only `impls_for`
+common: following the specification of exposition-only `impls_for`
 class template I used lambda functions for the various "overrides".
 One compiler complained about undefined symbols about these! Of
 course, using lambda functions in a header is problematic because
@@ -257,7 +257,7 @@ the headers.
 ## Changes Needed to Support Modules
 
 When enabling modules I needed to apply quite a few, mostly
-rather simple changes. Some of teh necessary changes did take
+rather simple changes. Some of the necessary changes did take
 me a bit to actually discover. Here is broadly what I needed
 to change:
 
@@ -318,7 +318,7 @@ to change:
     However, the compiler insisted in the definition of the function
     that neither of the two expressions from the `requires` clause
     was valid. Eventually I just turned the `query` into two
-    overloads, the first requring that `q(e1)` is valid and the
+    overloads, the first requiring that `q(e1)` is valid and the
     second requiring that `q(e1)` is not valid but `q(e2)` is valid.
     I think it was only one compiler causing this issue.
 
@@ -337,7 +337,7 @@ changed multiple tests needed to be built.
 
 The promise of `module`s was that builds get faster. I don't have
 objective measurements but it seems the development actually got
-slower. While concentrating on fixing a particular componenent I
+slower. While concentrating on fixing a particular component I
 often removed all other tests and the examples from the build.
 
 ## Modules vs. Testing

From ae12455041eb18c65aca1b23402a04101dda8e4f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Thu, 5 Feb 2026 23:26:35 +0000
Subject: [PATCH 7/9] added a date to the modules write-up

---
 docs/modules.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/modules.md b/docs/modules.md
index 3ea663e8..3c1286c8 100644
--- a/docs/modules.md
+++ b/docs/modules.md
@@ -1,6 +1,7 @@
 # Supporting Modules
 
 Author: Dietmar Kühl dietmar.kuehl@me.com
+Date: 2026-02-05
 
 Originally [`beman.execution`](https://github.com/bemanproject/execution)
 was implemented with out `module` support. Eventually, `module`

From 45f2e5edae94bbc329da96e0e1f417935559bc62 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Thu, 5 Feb 2026 23:44:37 +0000
Subject: [PATCH 8/9] spell check

---
 docs/modules.md | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/docs/modules.md b/docs/modules.md
index 3c1286c8..35f7199d 100644
--- a/docs/modules.md
+++ b/docs/modules.md
@@ -33,7 +33,7 @@ including the standard library headers.
 
 I had tried to create a `module` right after the Hagenberg meeting
 at the end of 2025. Since I was clueless how to go about that I had
-asked peolple who worked on the `module` specification and implemented
+asked people who worked on the `module` specification and implemented
 the corresponding support in compilers. The recommendation was to
 create a `module` file, include all the headers, start the `module`,
 and have `export using <name>;` declarations. That is, something
@@ -54,7 +54,7 @@ namespace beman::execution {
 
 Creating a file like that was fairly mechanical work and I just did
 it.  I tried it. There were a bunch of errors which I could work
-out easily but eventually I got stuck with unscruitible errors.
+out easily but eventually I got stuck with inscrutable errors.
 Since I never planned to write about the experience I don't recall
 what the errors were.  When I asked about it the message was that
 neither `cmake` nor the compilers are quite there. So I abandoned
@@ -110,7 +110,7 @@ compilers:
 
 <ol>
   <li>
-  The first 7 charactesr of a `module` file shall be `module;`
+  The first 7 characters of a `module` file shall be `module;`
   without anything preceding them.  [`g++`](https://gcc.gnu.org/)
   and [`clang++`](https://llvm.org/) are somewhat relaxed about
   this requirement but some compiler is rather strict. This, however,
@@ -127,14 +127,14 @@ compilers:
   is, all headers really need to be included before the name
   declaration. That is pretty much _not_ how the components in
   [`beman.execution`](https://github.com/bemanproject/execution) are
-  organized.
+  organised.
   </li>
 </ol>
 
 To still achieve the objective of `export`ing a name when it first
 gets declared, the structure needs to be changed. However, the components
-are organized in a consistent structure. So the idea is to use this structure
-to reorganize the files for `module` builds:
+are organised in a consistent structure. So the idea is to use this structure
+to reorganise the files for `module` builds:
 
 <ol>
   <li>
@@ -175,7 +175,7 @@ suitable `#line` directives to find the actual source. Compiling
 the resulting still didn't quite work, of course. There was a bunch
 of silly errors in the component headers which could be quickly
 resolved, though. That wasn't quite as true for the test files,
-though (more [ruminations on tests](#modules-vs-testing) below):
+though (more [rumination on tests](#modules-vs-testing) below):
 
 - Many tests didn't include all standard library headers they
   dependent on. Since the corresponding header were actually included
@@ -228,7 +228,7 @@ One compiler put up a fight, though! I'm using the an exposition-only
 compiler error about using <code>std::get&lt;N&gt;(<i>sender</i>)</code>.
 After some experimentation I found that `export`ing the `product_type`
 template and the relevant `tuple_size` and `tuple_element`
-specializations I could resolve this problem, too.
+specialisations I could resolve this problem, too.
 
 Once I got past that I encountered a problem which is probably quite
 common: following the specification of exposition-only `impls_for`
@@ -245,7 +245,7 @@ need to rewrite an implementation just to make it a `module`. I
 should also get away not needing any macros to insert/remove the
 `export` keywords from declarations. Instead, the `export`ed names
 are just listed in the module definition file. What is currently
-missing is a bit of a clean-up to remove some of the artifacts.
+missing is a bit of a clean-up to remove some of the artefacts.
 Also, there may be more implementation details exported than is
 actually necessary.
 
@@ -288,7 +288,7 @@ to change:
     Removing `#include <tuple>` causes a compilation failure:
     `sync_wait` return an `std::optional<std::tuple<T...>>` and the
     structured binding needs to know about the `std::tuple`. Oddly,
-    the `std::optional` can be deferenced.
+    the `std::optional` can be dereferenced.
 
 - My biggest blocker was the definition of `join_env`: the original
     definition used a `requires` clause which checked whether at
@@ -383,7 +383,7 @@ main sticking points are:
 2. The "scan deps" step seems to take quite long.
 3. So far I haven't managed to avoid `export`ing some of the implementation
     details. However, that _may_ be due to some uses actually requiring them.
-4. There is different behavior between different compilers.
+4. There is different behaviour between different compilers.
 
 Some of the issues I encountered are likely due to ignorance: probably
 all issues can be resolved with a bit of adjusted practices.

From f4df4d961e861f25e32edf8ff9e32d4b6106294e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dietmar=20K=C3=BChl?= <dietmar.kuehl@me.com>
Date: Thu, 5 Feb 2026 23:58:37 +0000
Subject: [PATCH 9/9] change to US spelling

---
 docs/modules.md | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/docs/modules.md b/docs/modules.md
index 35f7199d..91736936 100644
--- a/docs/modules.md
+++ b/docs/modules.md
@@ -127,14 +127,14 @@ compilers:
   is, all headers really need to be included before the name
   declaration. That is pretty much _not_ how the components in
   [`beman.execution`](https://github.com/bemanproject/execution) are
-  organised.
+  organized.
   </li>
 </ol>
 
 To still achieve the objective of `export`ing a name when it first
 gets declared, the structure needs to be changed. However, the components
-are organised in a consistent structure. So the idea is to use this structure
-to reorganise the files for `module` builds:
+are organized in a consistent structure. So the idea is to use this structure
+to reorganize the files for `module` builds:
 
 <ol>
   <li>
@@ -228,7 +228,7 @@ One compiler put up a fight, though! I'm using the an exposition-only
 compiler error about using <code>std::get&lt;N&gt;(<i>sender</i>)</code>.
 After some experimentation I found that `export`ing the `product_type`
 template and the relevant `tuple_size` and `tuple_element`
-specialisations I could resolve this problem, too.
+specialization I could resolve this problem, too.
 
 Once I got past that I encountered a problem which is probably quite
 common: following the specification of exposition-only `impls_for`
@@ -245,7 +245,7 @@ need to rewrite an implementation just to make it a `module`. I
 should also get away not needing any macros to insert/remove the
 `export` keywords from declarations. Instead, the `export`ed names
 are just listed in the module definition file. What is currently
-missing is a bit of a clean-up to remove some of the artefacts.
+missing is a bit of a clean-up to remove some of the artifacts.
 Also, there may be more implementation details exported than is
 actually necessary.
 
@@ -383,7 +383,7 @@ main sticking points are:
 2. The "scan deps" step seems to take quite long.
 3. So far I haven't managed to avoid `export`ing some of the implementation
     details. However, that _may_ be due to some uses actually requiring them.
-4. There is different behaviour between different compilers.
+4. There is different behavior between different compilers.
 
 Some of the issues I encountered are likely due to ignorance: probably
 all issues can be resolved with a bit of adjusted practices.