[Bug libstdc++/113841] Can't swap two std::hash

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113841

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c++                         |libstdc++

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Actually, maybe we need this change in the library, so that it works in GCC 12
and also works with Clang:

--- a/libstdc++-v3/include/bits/stl_vector.h
+++ b/libstdc++-v3/include/bits/stl_vector.h
@@ -135,6 +135,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
        _GLIBCXX20_CONSTEXPR
        _Vector_impl() _GLIBCXX_NOEXCEPT_IF(
            is_nothrow_default_constructible<_Tp_alloc_type>::value)
+#if __cpp_lib_concepts
+       requires is_default_constructible_v<_Tp_alloc_type>
+#endif
        : _Tp_alloc_type()
        { }