https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106889
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #2) > I think std::strlen isn't constexpr even in latest C++, so all of this is > permitted by the standard... Right, which is why I recommend using char_traits::length instead.