[Bug libstdc++/101485] Calling std::equal with std::byte* does not use memcmp

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101485

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
A better version of the concept sketched above:

template<typename T>
concept is_sane_enum = std::is_enum_v<T> && (!requires {
  []<std::convertible_to<bool> U>(U (*)(T, T)){}(&operator==);
});