https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103891
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:5b417b35824fb5c15e3ee958cb86436b3409ebea commit r12-6439-g5b417b35824fb5c15e3ee958cb86436b3409ebea Author: Jonathan Wakely <jwak...@redhat.com> Date: Mon Jan 10 17:28:19 2022 +0000 libstdc++: Make std::variant work with Clang in C++20 mode [PR103891] Clang has some bugs with destructors that use constraints to be conditionally trivial, so disable the P2231R1 constexpr changes to std::variant unless the compiler is GCC 12 or later. If/when P2493R0 gets accepted and implemented by G++ we can remove the __GNUC__ check and use __cpp_concepts >= 202002 instead. libstdc++-v3/ChangeLog: PR libstdc++/103891 * include/bits/c++config (_GLIBCXX_HAVE_COND_TRIVIAL_SPECIAL_MEMBERS): Define. * include/std/variant (__cpp_lib_variant): Only define C++20 value when the compiler is known to support conditionally trivial destructors. * include/std/version (__cpp_lib_variant): Likewise.
