Only the [cmp.alg] part (for `comparison_meow_fallback` CPOs) in the
paper required changes. Other parts merely fixed preconditions of some
standard library functions.
I strongly feel that P2167R3 should be a DR despite that it is not a DR
officially: CPOs -> C++20; remain parts -> C++98/11 (except that
_`boolean-testable`_ should be transformed into the original
_BooleanTestable_ requirements in the old resolution of LWG2114).
Note that P2167R3 damaged the resolution of LWG3465: the type of `F < E`
was left underconstrained. I've tried to submit an LWG issue for this,
which is now LWG4157.
Drive-by change:
- enable some test coverages in `compare_strong_order_fallback.pass.cpp`
when `TEST_LONG_DOUBLE_IS_DOUBLE`, following up #106742Closes#105241.
This reverts commit 78f9a8b82d772ff04a12ef95f2c9d31ee8f3e409.
This caused the LLDB test `TestDataFormatterGenericOptional.py` to fail, and we need
a bit more time to look into it.
Instead of changing the cast sequence to implicit conversion in
_`voidify`_, I think it is better to totally remove `__voidify` and use
`static_cast` to `void*`, which has equivalent effects.
Test coverage for const iterators are removed.
Now most affected algorithms are underconstrained, for which I submitted
[LWG3888](https://cplusplus.github.io/LWG/issue3888). I'm not sure
whether we should speculatively implement it at this moment, and thus
haven't added any `*.verify.cpp`.
In some control block types and `optional`, the stored objects are
changed to have cv-unqualified type.
Fixes#105119.
The paper was implemented by commit b0386a515b60c
(https://reviews.llvm.org/D46845) in LLVM 7.0. But it would be nice to
have test coverage for desired properties of `insert_return_type`.
Closes#99944
This ABI break only affects fancy pointer which have a different value
representation when pointing to a base of T instead of T itself. This
seems like a rather small set of fancy pointers, which themselves
already represent a very small niche. This patch swaps a pointer to T
with a pointer to base of T in a few library-internal types.
Works towards P0619R4 / #99985.
The use of `std::get_temporary_buffer` and `std::return_temporary_buffer`
are replaced with `unique_ptr`-based RAII buffer holder.
Escape hatches:
- `_LIBCPP_ENABLE_CXX20_REMOVED_TEMPORARY_BUFFER` restores
`std::get_temporary_buffer` and `std::return_temporary_buffer`.
Drive-by changes:
- In `<syncstream>`, states that `get_temporary_buffer` is now removed,
because `<syncstream>` is added in C++20.
This significantly simplifies the code, improves compile times and
improves the object layout of types using `__compressed_pair` in the
unstable ABI. The only downside is that this is extremely ABI sensitive
and pedantically breaks the ABI for empty final types, since the address
of the subobject may change. The ABI of the whole object should not be
affected.
Fixes#91266Fixes#93069
There are a few lines in the release notes which are much wider than the
120 columns we usually use. This reflows the text to keep it below the
threshold.
We waited before supporting std::jthread fully because we wanted to
investigate other implementation strategies (in particular one involving
std::mutex). Since then, we did some benchmarking and decided that we
wouldn't be moving forward with std::mutex. Hence, there is no real
reason to punt on making std::jthread & friends non-experimental.
They were originally implemented in d42db7e083ee0 but reverted later in
a2f3c63282330be0.
This PR implement both LWG issues again, guarding the removed functions
with `_LIBCPP_STD_VER <= 14`, because they should be treated as patches
for P0302R1 which was adopted for C++17.
Fixes#103598Fixes#103755
The resolution of LWG2593 didn't require the standard library
implementation to change. It merely strengthened requirements on
user-defined allocator types and allowed the implementation to make
stronger assumptions. The status is tentatively set to Nothing To Do.
However, `test_allocator` in libc++'s test suit needs to be fixed to
conform to the strengthened requirements.
Closes#100220.
This patch replaces 'tags' in the CSV status pages by inline notes
that optionally describe more details about the paper/LWG issue.
Tags were not really useful anymore because we have a vastly superior
tagging system via Github issues, and keeping the tags up-to-date
between CSV files and Github is going to be really challenging.
This patch also adds support for encoding custom notes in the CSV
files via Github issues. To encode a note in the CSV file, the
body (initial description) of a Github issue can be edited to contain
the following markers:
BEGIN-RST-NOTES
text that will be added as a note in the RST
END-RST-NOTES
Amongst other things, this solves the problem of conveying that a
paper has been implemented as a DR, and it gives a unified way to
add notes to the status pages from Github.
Please refer to the Github issues for details on why those are marked
as resolved. Huge thanks to @frederick-vs-ja for the analysis.
Closes#104336Closes#100042Closes#100615
This patch implements https://wg21.link/P2747R2.
The library changes affect direct `operator new` and `operator new[]`
calls even when the core language changes are absent.
The changes are not available for MS ABI because the `operator new` and
`operator new[]` are from VCRuntime's `<vcruntime_new.h>`. A feature
request was submitted for that [1].
As a drive-by change, the patch reformatted the whole `new.pass.cpp` and
`new_array.pass.cpp` tests.
Closes#105427
[1]: https://developercommunity.visualstudio.com/t/constexpr-for-placement-operator-newope/10730304.
This patch implements https://wg21.link/p2609r3.
The test code was originally authored by JMazurkiewicz.
Notes:
- P2609R3 is not officially a Defect Report, but MSVC STL
implements it in C++20 mode.
Moreover, P2609R3 and P2997R1 touch exactly the same set of
concepts, and MSVC STL and libc++ have already treated P2997R1
as a DR.
- This patch also adjusted feature-test macros.
+ In C++20 mode, the value of __cpp_lib_ranges should be `202110L` because
- `202202L` covers `range_adaptor_closure` (P2387R3), and
- `202207L` covers move-only types in range adaptors (P2494R2).
And all of these changes are only available since C++23 mode.
+ In C++23 mode, the value should be `202406L` because
- `202211L` covers removing poison overloads (P2602R2),
- `202302L` covers relaxing projected value types (P2609R3), and
- `202406L` covers removing requirements on `iter_common_reference_t` (P2997R1).
And all of these changes are already or being implemented.
Fixes#105253.
Co-authored-by: Jakub Mazurkiewicz <mazkuba3@gmail.com>
Works towards P0619R4/#99985.
- std::uncaught_exception was not previously deprecated. This patch
deprecates it since C++17 as per N4259. std::uncaught_exceptions is
used instead as libc++ unconditionally provides this function.
- _LIBCPP_ENABLE_CXX20_REMOVED_UNCAUGHT_EXCEPTION restores
std::uncaught_exception.
- As a drive-by, this patch updates the C++20 status page to
explain that D.11 is already done, since it was done in
578d09c1b195d859ca7e62840ff6bb83421a77b5.
This trait is implemented in C++26 conditionally on the compiler
supporting the __builtin_is_virtual_base_of intrinsic. I believe only
tip-of-trunk Clang currently implements that builtin.
Closes#105432
Instead of tracking those using our static CSV files, I created lists of
subtasks in their respective issues (#99939 and #105169) to track the
work that is still left.
This patch removes obsolete status pages for projects that were
completed: LLVM 18 release, C++20 Ranges and Spaceship support.
Co-authored-by: Hristo Hristov <zingam@outlook.com>
- Landing page: add link to the libc++ Discord channel
- Landing page: reorder "Getting Involved" above "Design documents"
- Landing page: remove "Notes and Known Issues" which was completely outdated
- Rename "Using Libc++" to "User Documentation" and update contents
- Rename "Building Libc++" to "Vendor Documentation" and update contents
The "BuildingLibcxx" and "UsingLibcxx" pages have basically been used for
vendor and user documentation respectively. However, they were named in
a way that doesn't really make that clear. Renaming the pages now gives
us a location to clearly document what we target at vendors and what we
target at users, and to do that separately.
Instead of having various status entries like 'Superseded by XXX',
we use '|Nothing To Do|' but we add a note explaining that the paper
was pulled at another meeting.
We already documented that libc++ was C++14 complete, but we still
documented the status of C++14. Since that is redundant (and I suspect
the C++14 status page was missing some stuff), simply remove them.
The function
template<class Duration>
requires three_way_comparable_with<sys_seconds, sys_time<Duration>>
constexpr auto operator<=>(const leap_second& x, const
sys_time<Duration>& y) noexcept;
Has a recursive constrained. This caused an infinite loop in GCC and is
now hit by https://github.com/llvm/llvm-project/pull/102857.
A fix would be to make this function a hidden friend, this solution is
propsed in LWG4139.
For consistency all comparisons are made hidden friends. Since the issue
causes compilation failures no additional test are needed.
Fixes: https://github.com/llvm/llvm-project/issues/104700
In LLVM 19 removed the extension with an opt-in macro. This finally
removes that option too and removes a few `const_cast`s where I know
that they exist only to support this extension.
We can only track existing LWG issues because we need a valid LWG issue
number for all issues. I'll create another GH issue to track creating
that LWG issue instead.
- LWG2308 was voted into C++14 in the 2014 Issaquah meeting
- LWG2682 was voted into C++20 in San Diego 2018, not C++17 in Issaquah
- LWG2769 was voted into C++17 in Kona 2017, not Issaquah 2016
## Introduction
This patch implements LWG3564:
`transform_view::iterator<true>::value_type` and `iterator_category`
should use `const F&`.
`transform_view`'s iterator currently obtained from a `const
transform_view` invoke the transformation function as `const`, but the
`value_type` and `iterator_category` determination uses non-`const`
`F&`.
## Reference
-
[[range.transform.iterator]](https://eel.is/c++draft/range.transform.iterator)
- [LWG3564](https://cplusplus.github.io/LWG/issue3564)
This adds addressof at the required places in [input.output]. Some of
the new tests failed since string used operator& internally. These have
been fixed too.
Note the new fstream tests perform output to a basic_string instead of a
double. Using a double requires num_get specialization
num_get<CharT, istreambuf_iterator<CharT,
char_traits_operator_hijacker<CharT>>
This facet is not present in the locale database so the conversion would
fail due to a missing locale facet. Using basic_string avoids using the
locale.
As a drive-by fixes several bugs in the ofstream.cons tests. These
tested ifstream instead of ofstream with an open mode.
Implements:
- LWG3130 [input.output] needs many addressof
Closes#100246.
The tests kept being based on std::string instead of std::string_view to
allow testing with older C++ dialects.
Adds tests for:
- LWG3112 system_error and filesystem_error constructors taking a string
may not be able to meet their postconditions
