This defines a new policy for removal of transitive includes.
The goal of the policy it to make it relatively easy to remove
headers when needed, but avoid breaking developers using and
vendors shipping libc++.
The method used is to guard transitive includes based on the
C++ language version. For the upcoming C++23 we can remove
headers when we want, but for other language versions we try
to keep it to a minimum.
In this code the transitive include of `<chrono>` is removed
since D128577 introduces a header cycle between `<format>`
and `<chrono>`. This cycle is indirectly required by the
Standard. Our cycle dependency tool basically is a grep based
tool, so it needs some hints to ignore cycles. With the input
of our transitive include tests we can create a better tool.
However that's out of the scope of this patch.
Note the flag `_LIBCPP_REMOVE_TRANSITIVE_INCLUDES` remains
unchanged. So users can still opt-out of transitives includes
entirely.
Reviewed By: #libc, ldionne, philnik
Differential Revision: https://reviews.llvm.org/D132284
Also fix `ranges::stable_sort` and `ranges::inplace_merge` to support
proxy iterators now that their internal implementations can correctly
dispatch `rotate`.
Differential Revision: https://reviews.llvm.org/D130758
implement `std::ranges::set_intersection` by reusing the classic `std::set_intersenction`
added unit tests
Differential Revision: https://reviews.llvm.org/D129233
- P1252 ("Ranges Design Cleanup") -- deprecate
`move_iterator::operator->` starting from C++20; add range comparisons
to the `<functional>` synopsis. This restores
`move_iterator::operator->` that was incorrectly deleted in D117656;
it's still defined in the latest draft, see
http://eel.is/c++draft/depr.move.iter.elem. Note that changes to
`*_result` types from 6.1 in the paper are no longer relevant now that
these types are aliases;
- P2106 ("Alternative wording for GB315 and GB316") -- add a few
`*_result` types to the synopsis in `<algorithm>` (some algorithms are
not implemented yet and thus some of the proposal still cannot be
marked as done);
Also mark already done issues as done (or as nothing to do):
- P2091 ("Fixing Issues With Range Access CPOs") was already implemented
(this patch adds tests for some ill-formed cases);
- LWG 3247 ("`ranges::iter_move` should perform ADL-only lookup of
`iter_move`") was already implemented;
- LWG 3300 ("Non-array ssize overload is underconstrained") doesn't
affect the implementation;
- LWG 3335 ("Resolve C++20 NB comments US 273 and GB 274") was already
implemented;
- LWG 3355 ("The memory algorithms should support move-only input
iterators introduced by P1207") was already implemented (except for
testing).
Differential Revision: https://reviews.llvm.org/D126053
This commit re-adds transitive includes that had been removed by
4cd04d1687f1, c36870c8e79c, a83f4b9cda57, 1458458b558d, 2e2f3158c604,
and 489637e66dd3. This should cover almost all the includes that had
been removed since LLVM 14 and that would contribute to breaking user
code when releasing LLVM 15.
It is possible to disable the inclusion of these headers by defining
_LIBCPP_REMOVE_TRANSITIVE_INCLUDES. The intent is that vendors will
enable that macro and start fixing downstream issues immediately. We
can then remove the macro (and the transitive includes) by default in
a future release. That way, we will break users only once by removing
transitive includes in bulk instead of doing it bit by bit a every
release, which is more disruptive for users.
Note 1: The set of headers to re-add was found by re-generating the
transitive include test on a checkout of release/14.x, which
provided the list of all transitive includes we used to provide.
Note 2: Several includes of <vector>, <optional>, <array> and <unordered_map>
have been added in this commit. These transitive inclusions were
added when we implemented boyer_moore_searcher in <functional>.
Note 3: This is a best effort patch to try and resolve downstream breakage
caused since branching LLVM 14. I wasn't able to perfectly mirror
transitive includes in LLVM 14 for a few headers, so I added a
release note explaining it. To summarize, adding boyer_moore_searcher
created a bunch of circular dependencies, so we have to break
backwards compatibility in a few cases.
Differential Revision: https://reviews.llvm.org/D128661
This patch also adds a new optimization to `std::move`. It unwraps three `reverse_iterator`s if the wrapped iterator is a `contiguous_iterator` and the iterated type is trivially_movable. This allows us to simplify `ranges::move_backward` to a forward to `std::move` without any pessimization.
Reviewed By: var-const, #libc
Spies: libcxx-commits, mgorny
Differential Revision: https://reviews.llvm.org/D126616
