https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103951
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- This would be solved by http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2499r0.html but I think the std::lib code is behaving exactly as the C++23 draft requires.
