https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92850
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to fdlbxtqi from comment #2) > "Are you sure concepts are fully implemented in clang?" > > Yes, but feature testing macro is missing. No, it very obviously doesn't support concepts: https://godbolt.org/z/n4AkpC So that will be why it doesn't define the macro.
