Function enum_flags_test

include/magic_enum/magic_enum_flags.hpp:197–201

// Note: If `flag` equals 0, it returns false, as 0 is not a flag.
template <typename E>
constexpr auto enum_flags_test(E flags, E flag) noexcept -> detail::enable_if_t<E, bool> {
  using U = underlying_type_t<E>;

  return static_cast<U>(flag) && ((static_cast<U>(flags) & static_cast<U>(flag)) == static_cast<U>(flag));
}

// Returns true if `lhs flags set` and `rhs flags set` have common flags.
// Note: If `lhs flags set` or `rhs flags set` equals 0, it returns false, as 0 is not a flag, and therfore cannot have any matching flag.