https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88545
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #2)
> + using _ValT = typename iterator_traits<_InputIterator>::value_type;
> + if constexpr (is_same_v<_ValT, _Tp>)
> + if constexpr (__is_byte<_ValT>::__value)
We can do better than this.
We can use memchr to find a char in a range of signed char, or even to find an
int in a range of signed char, as long as we're careful about values.
For example, given s = "abc"sv, std::find(s.begin(). s.end(), 'a'+0) should
find a match, but std::find(s.begin(), s.end(), 'a'+256) should not (even
though memchr would match in that case, because it does (unsigned
char)('a'+256)).
We should also ensure that std::ranges::find gets the same optimizations.
