https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94933
--- Comment #2 from rhalbersma <rhalbersma at gmail dot com> --- Sorry, my bad, but that particular overload of __fill_a1 calls __builtin_memset. I was under the impression that this was the reason for the missing constexpr. It would be great if simply adding _GLIBCXX20_CONSTEXPR would fix it.
