The `basic_string_view` constructor accepting a contiguous range rejects
converting between `basic_string_view` even when only the trait types vary.
This prevents conversions for converting from `basic_string_view<C, T1>` and
`basic_string<C, T1, A>` to `basic_string_view<C, T2>`. Recently, this
constructor was made `explicit`, so there's no reason to really forbid this
conversion anymore.
Relax the restriction that the trait types need to match in this constructor.
Differential Revision: https://reviews.llvm.org/D143972
Partially implements:
- P1361 Integration of chrono with text formatting
- P2372 Fixing locale handling in chrono formatters
- P1466 Miscellaneous minor fixes for chrono
Depends on D137022
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D139771
Instead of destroying the object with allocator::destroy, we must
call its destructor directly. As a fly-by also mark LWG3008 as
fixed since it is handled by our implementation.
This was pointed out by Tim Song in https://reviews.llvm.org/D140913.
Differential Revision: https://reviews.llvm.org/D143791
The implementation makes use of the freedom added by LWG 3410. We have
two variants of this algorithm:
* a fast path for random access iterators: This fast path computes the
maximum number of loop iterations up-front and does not compare the
iterators against their limits on every loop iteration.
* A basic implementation for all other iterators: This implementation
compares the iterators against their limits in every loop iteration.
However, it still takes advantage of the freedom added by LWG 3410 to
avoid unnecessary additional iterator comparisons, as originally
specified by P1614R2.
https://godbolt.org/z/7xbMEen5e shows the benefit of the fast path:
The hot loop generated of `lexicographical_compare_three_way3` is
more tight than for `lexicographical_compare_three_way1`. The added
benchmark illustrates how this leads to a 30% - 50% performance
improvement on integer vectors.
Implements part of P1614R2 "The Mothership has Landed"
Fixes LWG 3410 and LWG 3350
Differential Revision: https://reviews.llvm.org/D131395
LWG3781 The exposition-only alias templates cont-key-type and
cont-mapped-type should be removed
Libc++ never implemented these aliases.
Reviewed By: #libc, philnik, ldionne
Differential Revision: https://reviews.llvm.org/D142912
LWG2970 Return type of std::visit misspecified
Was applied in D86006 including tests.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D142840
LWG3798 Rvalue reference and iterator_category
The changes are only applied to `ranges::transform_view`, the other
views haven't been implemented yet.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D142815
LWG3764 reference_wrapper::operator() should propagate noexcept
As drive-by adds constexpr to the synopsis, since it has already been
implemented.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D142814
LWG3754 Class template expected synopsis contains declarations that do
not match the detailed description
This parts of the detailed synopsis that is not copied in libc++, so
effectively there's nothing to do.
Reviewed By: #libc, philnik
Differential Revision: https://reviews.llvm.org/D142809
The paper
- P2286R8 Formatting ranges
is fully implemented modulo its feature test macro. This macro has been
revised by
- LWG3750 Too many papers bump __cpp_lib_format
The new macro depends on
- P2585R0 Improving default container formatting
This paper revises parts of P2286R8 and adds new formatter
specializations. The specialization for debug strings has some wording
issues, which is addresses in this paper
- P2733R0 Fix handling of empty specifiers in std::format
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D142153
- implement `std::ranges::split_view` (last c++20 view)
- Work in process on testing iterator/sentinel, but since we are
getting closer to the deadline, I'd like to send the review early
Differential Revision: https://reviews.llvm.org/D142063
There are no tests for the aliases because clang doesn't diagnose deprecated template aliases currently.
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D127678
All C++20 Ranges papers and LWG issues are done, with the exception of
https://wg21.link/P2210R2 ("Superior String Splitting"), and marked as
such.
All of these were already implemented prior to this patch except bumping
the feature test macro `__cpp_lib_ranges` as required by
https://wg21.link/P2325R3 ("Views should not be required to be default
constructible"). Note that, even though P2325R3 was voted into C++23, it
was voted with a recommendation for vendors to retroactively apply the
change to C++20 (see https://github.com/cplusplus/papers/issues/1007).
Differential Revision: https://reviews.llvm.org/D139900
`subrange` is also a `tuple-like`. To avoid the add entire `subrange` dependencies to `tuple-like`, we need forward declaration of `subrange`. However, the class template constraints of `subrange` currently requires `__iterator/concepts.h`, which requires `<concepts>`. The problem is that currently `tuple-like` is used in several different places, including libc++ extension for pair constructors. we don't want to add `<concepts>` to pair and other stuff. So this change also created several small headers that `subrange`'s declaration needed inside `__iterator/concepts/`
Differential Revision: https://reviews.llvm.org/D136268
This is a preparation for the upcoming LLVM 17 release.
Reviewed By: ldionne, philnik, avogelsgesang, jloser, #libc
Differential Revision: https://reviews.llvm.org/D141304
Releasing the mutex before the call to notify_all is an optimization.
This optimization cannot be used here. The thread waiting on the
condition might destroy the associated resources — mutex + condition
variable — and the notifier thread will access an destroyed variable
— the condition variable. In fact, notify_all_at_thread_exit is meant
exactly to join on detached threads, and the waiting thread doesn't
expect for the notifier thread to access any further shared resources,
making this scenario very likely to happen. The waiting thread might
awake spuriously on the release of the mutex lock. The reorder is
necessary to prevent this race.
Further details can be found at https://cplusplus.github.io/LWG/issue3343.
Differential Revision: https://reviews.llvm.org/D105758
Some of the calendar types have landed before, this adds the missing
set. Note this does not complete the implementation of the chrono
formatters.
This removes the `chrono` header for some transitive include in C++17
mode. This is needed to avoid inclusion cycles.
Partially implements:
- P1361 Integration of chrono with text formatting
- P2372 Fixing locale handling in chrono formatters
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D137022
No real changes were needed, but add an assert for the pre-condition.
This implements:
- 3738 Missing preconditions for take_view constructor
Reviewed By: #libc, philnik
Differential Revision: https://reviews.llvm.org/D140568
The noexcept was already implemented, this only updates the synposis and
adds tests to validate that the functions are noexcept.
This implements:
- LWG3745 std::atomic_wait and its friends lack noexcept
Reviewed By: #libc, philnik
Differential Revision: https://reviews.llvm.org/D140575
Implements:
- LWG3792 __cpp_lib_constexpr_algorithms should also be defined in <utility>
Depends on D140407
Reviewed By: #libc, philnik, ldionne
Differential Revision: https://reviews.llvm.org/D140413
