[mrousavy]

Stacked on #1991.

Throwing Swift methods that return a Swift value now lend it to a SwiftResultConsumer while Swift still owns it. Before, Swift wrote the value into storage that C++ read back through tryMakeSwiftValue<T>(), which returned a swift::Optional<T>, and C++ allocated and freed a box for it on every successful call.

// Before
auto __result = withSwiftResult<::NitroTest::NamedVariant_cxx>([&](void* __outResult) {
  return _swiftPart.bounceVariant(variant, __outResult);
});
// After
auto __result = receiveSwiftResult<::NitroTest::NamedVariant_cxx>([&](const void* __onResult) {
  return _swiftPart.bounceVariant(variant, __onResult);
});

let value = try __implementation.bounceVariant(variant: variant.value)
withUnsafePointer(to: NamedVariant_cxx(value)) { pointer in
  margelo.nitro.SwiftResultConsumer.consume(__onResult, UnsafeRawPointer(pointer))
}
return bridge.Result_void.withValue()

Methods returning void, primitives, classes or imported C++ values keep their current bridges, and so do non-throwing methods and Swift callbacks. SwiftResultConsumerType is a SwiftPointerType, like the other pointer adapters.

Before the rebase onto current v1, I measured this in a local Release Hermes harness on the iOS simulator. Concatenating "hello" and "world" went from 151 ns to 97 ns per call, and two 32-character strings from 303 ns to 247 ns. The harness lives outside the repo, and I haven't run the benchmark app.

The standalone iOS suite passes. Android is unaffected because only Apple bridge code changed.

🤖 Generated with Claude Code

[vercel]

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