Remove slicing ub

Author: bugdea1er

include/tmp/file

@@ -7,6 +7,10 @@
 #include <ios>
 #include <istream>
 
+#ifdef __GLIBCXX__
+#include <ext/stdio_filebuf.h>
+#endif
+
 namespace tmp {
 
 /// tmp::file is a smart handle that manages a temporary file, ensuring
@@ -85,10 +89,15 @@ public:
 
 private:
   /// The underlying C file stream
-  std::unique_ptr<std::FILE, decltype(&std::fclose)> underlying;
+  std::unique_ptr<std::FILE, int(*)(std::FILE*)> underlying;
 
+#ifdef __GLIBCXX__
+  /// The underlying raw file device object
+  mutable __gnu_cxx::stdio_filebuf<char> sb;
+#else
   /// The underlying raw file device object
   std::filebuf sb;
+#endif
 };
 }    // namespace tmp
 

src/file.cpp

@@ -217,7 +217,6 @@ file::file(std::ios::openmode mode)
 #elif defined(_LIBCPP_VERSION)
   sb.__open(fileno(underlying.get()), mode);
 #else
-  static_assert(sizeof(std::filebuf) == sizeof(__gnu_cxx::stdio_filebuf<char>));
   sb = __gnu_cxx::stdio_filebuf<char>(underlying.get(), mode);
 #endif