https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77922
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #0) > pr.C:1:1: note: C++11 ‘constexpr’ only available with -std=c++11 or > -std=gnu++11 Also this note isn't true, because it's also available with -std=gnu++14, or with no option, etc.
