https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105027
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:20f2303b0ce6bbe412e852e6423daabd04c39ebb commit r11-9773-g20f2303b0ce6bbe412e852e6423daabd04c39ebb Author: Jonathan Wakely <jwak...@redhat.com> Date: Wed Mar 23 09:57:20 2022 +0000 libstdc++: Add missing constraints to std::bit_cast [PR105027] Our std::bit_cast was relying on the compiler to check for errors inside __builtin_bit_cast, instead of checking them as constraints. That means std::bit_cast was not SFINAE-friendly. This fix uses a requires-clause, so for old versions of Clang without concepts support the function will still be unconstrained. At some point in future we can remove the #ifdef __cpp_concepts check and rely on all compilers having full concepts support in C++20 mode. libstdc++-v3/ChangeLog: PR libstdc++/105027 * include/std/bit (bit_cast): Add constraints. * testsuite/26_numerics/bit/bit.cast/105027.cc: New test. (cherry picked from commit 4894d69a1f37d54b6a612e58053db477ff5ba832)
