When we ship LLVM 16, <ranges> won't be considered experimental anymore.
We might as well do this sooner rather than later.
Differential Revision: https://reviews.llvm.org/D132151
For an lvalue reference to a move only view x, views::all(x) gives hard error because the expression inside noexcept is not well formed and it is not SFINAE friendly.
Given a move only view type `V`, and a concept
```
template <class R>
concept can_all = requires {
std::views::all(std::declval<R>());
};
```
The expression `can_all<V&>` returns
libstdc++: false
msvc stl : false
libc++ : error: static_cast from 'V' to 'typename decay<decltype((std::forward<V &>(__t)))>::type' (aka 'V') uses deleted function
noexcept(noexcept(_LIBCPP_AUTO_CAST(std::forward<_Tp>(__t))))
The standard spec has its own problem, the spec says it is expression equivalent to `decay-copy(E)` but the spec of `decay-copy` does not have any constraint, which means the expression `decay-copy(declval<V&>())` is well-formed and the concept `can_all<V&>` should return true and should error when instantiating the function body of decay-copy. This is clearly wrong behaviour in the spec and we will probably create an LWG issue. But the libc++'s behaviour is clearly not correct. The `noexcept` is an "extension" in libc++ which is not in the spec, but the expression inside `noexpect` triggers hard error, which is not right.
Reviewed By: #libc, ldionne, var-const
Differential Revision: https://reviews.llvm.org/D128281
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
If you have a `begin() const` member, you don't need a `begin()` member
unless you want it to do something different (e.g. have a different return
type). So in general, //view// types don't need `begin()` non-const members.
Also, static_assert some things about the types in "types.h", so that we
don't accidentally break those properties under refactoring.
Differential Revision: https://reviews.llvm.org/D111231
This patch implements the underlying mechanism for range adaptors. It
does so based on http://wg21.link/p2387, even though that paper hasn't
been adopted yet. In the future, if p2387 is adopted, it would suffice
to rename `__bind_back` to `std::bind_back` and `__range_adaptor_closure`
to `std::range_adaptor_closure` to implement that paper by the spec.
Differential Revision: https://reviews.llvm.org/D107098
Since we officially don't support several older compilers now, we can
drop a lot of the markup in the test suite. This helps keep the test
suite simple and makes sure that UNSUPPORTED annotations don't rot.
This is the first patch of a series that will remove annotations for
compilers that are now unsupported.
Differential Revision: https://reviews.llvm.org/D107787
Adds a new CMake option to disable the usage of incomplete headers.
These incomplete headers are not guaranteed to be ABI stable. This
option is intended to be used by vendors so they can avoid their users
from code that's not ready for production usage.
The option is enabled by default.
Differential Revision: https://reviews.llvm.org/D106763
Louis Dionne