[range.slide.view] Replace conditional with call to max

[JohelEGP]

[range.slide.view] adds (via #5249)

auto sz = ranges::distance(base_) - n_ + 1;
if (sz < 0) sz = 0;
return to-unsigned-like(sz);

Which can be simplified to

auto sz = max({}, ranges::distance(base_) - n_ + 1);
return to-unsigned-like(sz);

[timsong-cpp]

I don't think requiring mental overload resolution among the multiple overloads of ranges::max to figure out the meaning of the the untyped braces is an improvement.

[JohelEGP]

That's std::max.

[timsong-cpp]

That's std::max.

It's not. We are in namespace ranges.

[JohelEGP]

It can be simpler:

return to-unsigned-like(max({}, ranges::distance(base_) - n_ + 1));

ranges::max accepts (https://godbolt.org/z/a49G3Y84b):

return to-unsigned-like(ranges::max({0}, ranges::distance(base_) - n_ + 1));

which should alleviate the concerns of #5250 (comment).

[JohelEGP]

That's std::max.

It's not. We are in namespace ranges.

IIRC, when inside a nested namespace, the convention is to qualify "overloaded" identifiers, like distance above. I don't see this documented at https://github.com/cplusplus/draft/wiki/Specification-Style-Guidelines, so going purely by [contents], unqualified max would indeed be ranges::max.

[JohelEGP]

which should alleviate the concerns of #5250 (comment).

Actually, that only alleviates my original, left-unsaid readability concern by replacing 0 with {}. Suggested "simplifications" certainly still need overload resolution.