All supported compilers that support C++20 now support concepts. So, remove
`_LIB_LIBCPP_HAS_NO_CONCEPTS` in favor of `_LIBCPP_STD_VER > 17`. Similarly in
the tests, remove `// UNSUPPORTED: libcpp-no-concepts`.
Differential Revision: https://reviews.llvm.org/D121528
The logic here is that we are disabling *only* things in `std::ranges::`.
Everything in `std::` is permitted, including `default_sentinel`, `contiguous_iterator`,
`common_iterator`, `projected`, `swappable`, and so on. Then, we include
anything from `std::ranges::` that is required in order to make those things
work: `ranges::swap`, `ranges::swap_ranges`, `input_range`, `ranges::begin`,
`ranges::iter_move`, and so on. But then that's all. Everything else (including
notably all of the "views" and the `std::views` namespace itself) is still
locked up behind `_LIBCPP_HAS_NO_INCOMPLETE_RANGES`.
Differential Revision: https://reviews.llvm.org/D118736
- Rename test files to follow conventions better
- Split constructor tests that were in a single file
- Add missing tests for take_view and transform_view's default constructors
- Add missing tests for transform_view's view/function constructor
- Fix include guards
- Mark some tests as being specific to libc++
Differential Revision: https://reviews.llvm.org/D108829
Joe Loser