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
- Update note for P0156 which was reverted in Kona, to avoid unusual status.
- Add the LWG issue number for an old C++14 NB comment.
- Fix broken link for LWG2118
- Capitalize paper numbers and links consistently
- Remove weird status '* *' which was likely added by mistake
- Make sure we always have the same number of entries. In particular, I
dropped the "Group" entry that was tracked for papers but not for LWG
issues, since I don't think that added much. The group is already
tracked on the paper itself.
- Add "Label" row to all the CSV files.
This is mechanical, but it's necessary if we want to process our CSV
files uniformly, for example to synchronize their state with Github
issues.
There were a few places where we didn't properly quote entries in the
CSV status pages, or where we followed inconsistent spacing. This causes
issue when trying to synchronize status pages with Github issues.
As mentioned in the LWG issue libc++ has already implemented the
optimization. This adds tests and documents the implementation defined
behaviour.
Drive-by fixes an initialization.
When we initially implemented the C++20 synchronization library, we
reluctantly accepted for the implementation to be backported to C++03
upon request from the person who provided the patch. This was when we
were only starting to have experience with the issues this can create,
so we flinched. Nowadays, we have a much stricter stance about not
backporting features to previous standards.
We have recently started fixing several bugs (and near bugs) in our
implementation of the synchronization library. A recurring theme during
these reviews has been how difficult to understand the current code is,
and upon inspection it becomes clear that being able to use a few recent
C++ features (in particular lambdas) would help a great deal. The code
would still be pretty intricate, but it would be a lot easier to reason
about the flow of callbacks through things like
__thread_poll_with_backoff.
As a result, this patch drops support for the synchronization library
before C++20. This makes us more strictly conforming and opens the door
to major simplifications, in particular around atomic_wait which was
supported all the way to C++03.
This change will probably have some impact on downstream users, however
since the C++20 synchronization library was added only in LLVM 10 (~3
years ago) and it's quite a niche feature, the set of people trying to
use this part of the library before C++20 should be reasonably small.
This is an intermediate and fairly mechanical step towards unifying the
benchmarks with the rest of the test suite. Moving this around requires
a few changes, notably making sure we don't throw a wrench into the
discovery process of the normal test suite. This won't be a problem
anymore once benchmarks are taken into account by the test setup out of
the box.
The polymorphic_allocator was added in C++17.
This issue was filed in 2022 so well after C++20. This issue adds an
operator==.
Starting with C++20 this adds a compiler generated operator!=. To have
the same behaviour in C++17 and C++20 (and later) a manual operator!= is
defined in C++17.
Implements
- LWG3683 operator== for polymorphic_allocator cannot deduce template
argument in common cases
- LWG3147 Definitions of "likely" and "unlikely" are likely to cause
problems Adjusts the requirements on programs using the Standard
library.
- LWG3328 Clarify that std::string is not good for UTF-8 Adds a
non-normative note, aimed at users of the Standard library.
- LWG3784 std.compat should not provide ::byte and its friends was
implemented during modules.
- LWG3062 Unnecessary decay_t in is_execution_policy_v should be
remove_cvref_t Was implemented while implementing parallel algorithms.
- LWG3362 Strike stop_source's operator!= The removed operator was never
implemented.
- LWG3616 LWG 3498 seems to miss the non-member swap for basic_syncbuf
This was implemented correctly from the start.
- LWG3199 istream >> bitset<0> fails This was implemented in
fc4486c2472b84384d4a31d2436a91bdb9b29792, might be in LLVM-9
- LWG3828 Sync intmax_t and uintmax_t with C2x Standardardized existing
practice.
- LWG3713 Sorted with respect to comparator (only) Wording issue in the
Standard.
- LWG3823 Unnecessary precondition for is_aggregate Changes the
preconditions
- LWG3826 Redundant specification [for overload of yield_value] Changes
a remark to a note
- LWG3203 span element access invalidation Update wording relevant for
users of the Standard library.
This implements the requirements for the container iterator requirements
for array, deque, vector, and `vector<bool>`.
Implements:
- LWG3352 strong_equality isn't a thing
Implements parts of:
- P1614R2 The Mothership has Landed
Fixes: https://github.com/llvm/llvm-project/issues/62486
The work was done in a8ae392718313e64e2d7bc092b00f51476c074b2 which
implements parts of
N4258: Cleaning-up noexcept in the Library
However that's paper Summary of Proposed Changes contains
No change in vector<bool>
This patch updates the status and as a few NFC cleanups. The fixed
version is based on the release page and might be off.
Updates
- LWG3778 vector<bool> missing exception specifications
