https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86590
--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #15) > (In reply to Jonathan Wakely from comment #14) > > That's been asked for repeatedly but will never happen, instead this is > > being added to C++2a: > > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0595r1.html > > > > So we'd do > > > > static _GLIBCXX17_CONSTEXPR size_t > > length(const char_type* __s) > > { > > #if __cplusplus >= 201703L > > if (std::is_constant_evaluated()) > > Hmm, std::is_constant_evaluated would only be declared for C++2a, so we'd > need to use the magic builtin directly here, not the std:: wrapper. So, what is the status of P0595R1, has it been voted into C++2a already, or will likely be voted in, something else? I can certainly implement __builtin_is_constant_evaluated .
