<algorithm>: ranges::clamp, the projection may be applied at most three times.

[fsb4000]

Fixes #1893

[fsb4000]

Where should I add tests? At https://github.com/microsoft/STL/blob/main/tests/std/tests/P0896R4_ranges_alg_minmax/test.cpp or create new tests?

[miscco]

Where should I add tests? At https://github.com/microsoft/STL/blob/main/tests/std/tests/P0896R4_ranges_alg_minmax/test.cpp or create new tests?

Yes, that would be the best one. The "easiest" way would be to create a constexpr statefull projection and use that in the tests

[fsb4000]

Thank you @Serikov ! I'm a little confused.
It seems gcc is just using two copies with no forward / move and no if constexpr for move-only types.
cppreference has "Possible implementation" with two forwards
https://en.cppreference.com/w/cpp/algorithm/ranges/clamp
If we determine that this is incorrect, then we can fix it on cppreference too.
Unfortunately, I do not yet understand which option is correct. I will wait for more opinions.

[Serikov]

@fsb4000 Sorry for the confusion. My understanding was wrong. Apparently that example contains precondition violation. More then that GCC clamp implementation is buggy. There is an answer on StackOverlow that clarifies why it is required to forward arguments twice (there is a link to an example in the comments).

[CaseyCarter]

I'm going to add this to the next batch of changes to merge - please notify me if any further commits are pushed.

[CaseyCarter]

Thank you for ensuring the number of projections in clamp are within bounds!