https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113960
--- Comment #6 from Stefan Schulze Frielinghaus <stefansf at linux dot ibm.com>
---
Guard __is_byte_iter checks for contiguous bytes which I guess is fine for
std::vector and then checks for __is_memcmp_ordered which is fine for
big-endian targets in conjunction with unsigned integers. From
cpp_type_traits.h we have:
// Whether memcmp can be used to determine ordering for a type
// e.g. in std::lexicographical_compare or three-way comparisons.
// True for unsigned integer-like types where comparing each byte in turn
// as an unsigned char yields the right result. This is true for all
// unsigned integers on big endian targets, but only unsigned narrow
// character types (and std::byte) on little endian targets.
template<typename _Tp, bool _TreatAsBytes =
#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
__is_integer<_Tp>::__value
#else
__is_byte<_Tp>::__value
#endif
Thus using memcmp here is fine, however, I'm still a bit unsure whether we
really have to take the minimum of *__first1 and *__first2 since I haven't
found any size-relation between those types.
