https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94753
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- Maybe I've misunderstood you, but the feature test macros for C++11 features should definitely be defined for C++11. They're not "system-specific" or "GCC-specific". Just because they weren't in the standard prior to C++20 doesn't mean they shouldn't be defined when the corresponding feature is supported.
