72 Commits

Author SHA1 Message Date
William Tran-Viet
1c51886920
[libc++] Implement P3168R2: Give optional range support (#149441)
Resolves #105430

- Implement all required pieces of P3168R2
- Leverage existing `wrap_iter` and `bounded_iter` classes to implement
the `optional` regular and hardened iterator type, respectively
- Update documentation to match
2025-08-18 18:04:45 +03:00
A. Jiang
4a509f853f
[libc++] Implement comparison operators for tuple added in C++23 (#148799)
And constrain the new `operator==` since C++26.

This patch implements parts of P2165R4, P2944R3, and a possibly improved
resolution of LWG3882. Currently, libstdc++ and MSVC STL constrain the
new overloads in the same way.

Also set feature-test macro `__cpp_lib_constrained_equality` and add
related release note, as P2944R3 will completed with this patch.

Fixes #136765
Fixes #136770
Fixes #105424
2025-08-01 11:53:33 -04:00
A. Jiang
3d688233bd
[libc++][docs] Add missing entry for status pages, fix bad formatting, and deduplicate (#148186)
In a previously PR, the entry for P3491R3 define_static_{string,object,array} was missing.
This patch adds it back.

The number of LWG2687, LWG2709, LWG3315, LWG3395, LWG3987, and LWG4113
were duplicated in the title. It seems better to avoid such duplicates.

Also fixes some formatting to properly use italic and code styles, and
remove one improper leading space from the title of P3682R0 (which
caused incorrect alignment in the generated page).
2025-07-15 11:14:41 -04:00
Hristo Hristov
5fc844acd8
[libc++] P2944R3: Constrained comparisons - optional (#144249)
Partially implements [P2944R3](https://wg21.link/P2944R3) which adds
constrained comparisons to std::optional.

Closes #136767


# References
[optional.relops](https://wg21.link/optional.relops)
[optional.comp.with.t](https://wg21.link/optional.comp.with.t)

---------

Co-authored-by: Hristo Hristov <zingam@outlook.com>
2025-07-15 10:12:39 +02:00
A. Jiang
e8a50a2568
[libc++][docs] Update paper & LWG issue lists after 2025-06 meeting (#147668)
CWG papers requiring library support are also listed.
2025-07-10 08:56:36 +08:00
Hristo Hristov
a19d37044b
[libc++] P2944R3: Constrained comparisions - tuple (#145677)
Implements P2944R3 partially, which adds constrained comparisons
`std::tuple`.
The missing overloads introduced in [P2165R4](https://wg21.link/P2165R4)
are not implemented.

Uses
[`__all`](f7af33a9eb/libcxx/include/__type_traits/conjunction.h (L45))
instead of a fold expression, see comment:
https://github.com/llvm/llvm-project/pull/141396#discussion_r2161166077

Relates to #136765

# References

[tuple.rel](https://wg21.link//tuple.rel)
2025-06-27 20:12:18 +03:00
Hristo Hristov
f2f4b557aa
[libc++] P2944R3: Constrained comparisions - variant (#141396)
This is a follow-up and depends on #139368 being merged first.

Implements [P2944R3](https://wg21.link/P2944R3) partially, which adds
constrained comparisons to `std::variant`

Closes #136769

Depends on #139368

# References

[variant.relops](https://wg21.link/variant.relops)
2025-06-25 12:12:23 +03:00
Hui
831fcb5e91
[libc++] constexpr flat_map (#137453)
Fixes #128673
2025-06-21 13:41:32 +01:00
Hristo Hristov
a0c00ccd5f
[libc++] P2944R3: Constrained comparisons - update reference_wrapper implementation (#139368)
Updates the implementation `std::reference_wrapper` -
[P2944R3](https://wg21.link/P2944R3) as discussed in
https://github.com/llvm/llvm-project/pull/117664#discussion_r1857826166
This PR also refactors the tests in preparation to implements the
constrained comparisons for `optional`, `variant` etc.

- Moves the test helpers (concepts and types) for testing constrained
comparisons to `test_comparisons.h`.
- Updates the `std::reference_wrapper` implementation to use the concept
`__core_convertible_to<bool>` as per comments in #135759.

Closes #138233

# References:
- [refwrap.comparisons](https://wg21.link/refwrap.comparisons)

---------

Co-authored-by: Hristo Hristov <zingam@outlook.com>
Co-authored-by: Nikolas Klauser <nikolasklauser@berlin.de>
2025-06-15 07:45:48 +03:00
yronglin
13c464be84
[libc++] Implement P3379R0 Constrain std::expected equality operators (#135759)
Closes #118135

Co-authored-by: A. Jiang <de34@live.cn>
2025-05-07 15:25:00 -04:00
A. Jiang
fc281e1b4f
[libc++][docs] Confirm that P3136R1 Retiring niebloids is Complete (#135932)
As libc++ has been implementing niebloids as CPOs since LLVM 14 due to
https://reviews.llvm.org/D116570.

Also changes some comments in test files to use the formal term
"algorithm function object".

Closes #118133.
2025-05-07 15:20:43 -04:00
Hristo Hristov
4ed8f38e81
[libc++][pair] P2944R3: Constrain std::pair's equality operator (#136672)
Implements https://wg21.link/P2944R3 (partially):
- [pairs.spec](https://eel.is/c++draft/pairs.spec)

Related issues:
- Related to #105424
- Related to #118135
  - PR https://github.com/llvm/llvm-project/pull/135759
  - PR https://github.com/llvm/llvm-project/pull/117664

Closes: [#136763](https://github.com/llvm/llvm-project/issues/136763)

# References
- https://eel.is/c++draft/concept.booleantestable
- https://eel.is/c++draft/concept.equalitycomparable

---------

Co-authored-by: Hristo Hristov <zingam@outlook.com>
Co-authored-by: Nikolas Klauser <nikolasklauser@berlin.de>
2025-04-29 22:00:16 +03:00
Damien L-G
557e931d95
[libc++] Implement P2897R7 aligned_accessor: An mdspan accessor expressing pointer over-alignment (#122603)
Closes #118372
2025-04-14 17:33:57 -04:00
A. Jiang
ab95005a05
[libc++] P3247R2: Deprecate is_trivial(_v) (#130573)
Requirements on character-like types are updated unconditionally,
because `basic_string` does requires the default-constructibility. It
might be possible to make `basic_string_view` support classes with
non-public trivial default constructor, but this doesn't seem sensible.

libcxxabi's `ItaniumDemangle.h` is also updated to avoid deprecated
features.
2025-04-09 07:40:01 +08:00
Amr Hesham
357306572d
[libcxx] Put std::monostate in <utility> (#128373)
Fixes: #127874
2025-03-25 18:31:57 +01:00
A. Jiang
6038077dde
[libc++] Bump __cpp_lib_constexpr_algorithms for P2562R1 in C++26 (#132075)
Completes P2562R1.
2025-03-21 07:33:52 +08:00
Louis Dionne
3a00c428d9
[libc++] Add Hagenberg issues and papers to the Status pages (#127510)
Corresponding Github issues will be created shortly.
2025-02-18 15:09:39 -05:00
Louis Dionne
ec54403522 [libc++] Synchronize a few remaining status page rows with Github issues 2025-02-17 10:26:10 -05:00
Louis Dionne
fb29f19fdb [libc++] Synchronize status pages with Github issues list 2025-02-17 10:16:56 -05:00
PaulXiCao
438e2ccd4a
[libc++] Make std::stable_sort constexpr friendly (#110320)
Implementing `constexpr std::stable_sort`. This is part of P2562R1,
tracked via issue #105360.

Closes #119394

Co-authored-by: A. Jiang <de34@live.cn>
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
2025-01-14 10:24:35 -05:00
Jakub Mazurkiewicz
c91d805e66
[libc++] Implement std::not_fn<NTTP> (#86133)
Implement `std::not_fn<NTTP>` from "P2714R1 Bind front and back to NTTP callables".
2025-01-10 14:14:14 -05:00
A. Jiang
c2950982fe
[libc++] Add Wroclaw straw polls (#118116) 2024-12-02 08:54:07 -05:00
h-vetinari
8b19d29a3f
[libc++] remove minor version in status pages (#113241)
Minor version of releases starts at `N.1.0` for all releases since 4532617ae42005.

The current status pages are not terribly wrong (the version during
development can be considered `N.0`), but still it's kinda weird to use
versions that never get released as the lower bound.
2024-11-04 10:48:50 -05:00
A. Jiang
cae351f345
[libc++] Bump __cpp_lib_optional and __cpp_lib_variant (#113650)
In C++20 mode, `__cpp_lib_optional` and `__cpp_lib_variant` should be
`202106L` due to DR P2231R1.

In C++26 mode, `__cpp_lib_variant` should be bumped to `202306L` due to
P2637R3.
- Clang 16/17 shouldn't get this bumping (as member `visit` requires
explicit object parameters), but it's very tricky to make the bumping
conditionally enabled. I _hope_ unconditionally bumping in C++26 will be
OK for LLVM 20 when the support for Clang 17 is dropped.

Related PRs:
- https://reviews.llvm.org/D102119
- #83335
- #76447
2024-10-26 07:38:52 +08:00
Louis Dionne
c2cac69d08
[libc++] Replace 'tags' in CSV status pages by inline notes (#105581)
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.
2024-08-28 13:42:41 -04:00
A. Jiang
7808541fde
[libc++] P2747R2: constexpr placement new (library part) (#105768)
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.
2024-08-28 09:35:57 -04:00
Louis Dionne
1c48c9cc43
[libc++] Implement P2985R0: std::is_virtual_base_of (#105847)
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
2024-08-26 09:58:19 -04:00
Louis Dionne
e80bc77774 [libc++] Normalize how we track the meeting at which a paper of LWG issue was voted
This uses the same values as we use in the Github project that tracks
Standards conformance.
2024-08-13 16:58:24 -04:00
Louis Dionne
b6262880b3
[libc++] Consistency fixes for the CSV status files (#101572)
- 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.
2024-08-02 09:13:20 -04:00
Hristo Hristov
cb3de24b5c
[libc++][iterator][ranges] P2997R1: Removing the common reference requirement from the indirectly invocable concepts (#98817)
Implements as DR against C++20: https://wg21.link/P2997R1

References:
- https://eel.is/c++draft/indirectcallable.indirectinvocable
- https://eel.is/c++draft/version.syn#header:%3cversion%3e

---------

Co-authored-by: Hristo Hristov <zingam@outlook.com>
2024-07-18 14:54:29 +03:00
Hristo Hristov
4a19be5d45
[libc++][strings] P2591R5: Concatenation of strings and string views (#88389)
Implemented: https://wg21.link/P2591R5
- https://eel.is/c++draft/string.syn
- https://eel.is/c++draft/string.op.plus

---------

Co-authored-by: Hristo Hristov <zingam@outlook.com>
2024-07-18 13:26:37 +03:00
Xiaoyang Liu
4e338dce4d
[libc++] P2389R2: dextents Index Type Parameter (#97393)
This patch implements P2389R2, which was adopted at the St. Louis meeting.
It builds upon previous enhancements from P2299R3, which introduced deduction
guides and the `dextents` alias template.
2024-07-15 11:23:34 -04:00
Hristo Hristov
31c9c41873
[libc++][tuple][utility] P2968R2: Make std::ignore a first-class object (#97401)
Implements:  https://wg21.link/P2968R2

References:
- https://eel.is/c++draft/tuple.general
- https://eel.is/c++draft/tuple.syn
- https://eel.is/c++draft/tuple.creation
- https://github.com/cplusplus/draft/milestone/31
- https://github.com/cplusplus/draft/pull/7109
- https://github.com/cplusplus/papers/issues/1640
- https://cplusplus.github.io/LWG/issue2933
- https://cplusplus.github.io/LWG/issue3978

---------

Co-authored-by: Hristo Hristov <zingam@outlook.com>
2024-07-11 00:05:23 +03:00
Mark de Wever
2dadf8d7f5
[libc++] Update status after the St. Louis meeting. (#97951)
This updates:
- The status tables
- Feature test macros
- New headers for modules
2024-07-08 19:35:31 +02:00
Nico Weber
716ed5fccd
[libc++] Undeprecate shared_ptr atomic access APIs (#92920)
This patch reverts 9b832b72 (#87111):
- [libc++] Deprecated `shared_ptr` Atomic Access APIs as per P0718R2
- [libc++] Implemented P2869R3: Remove Deprecated `shared_ptr` Atomic Access APIs from C++26

As explained in [1], the suggested replacement in P2869R3 is `__cpp_lib_atomic_shared_ptr`,
which libc++ does not yet implement. Let's not deprecate the old way of doing things before
the new way of doing things exists.

[1]: https://github.com/llvm/llvm-project/pull/87111#issuecomment-2112740039
2024-06-07 11:31:17 -04:00
Hristo Hristov
8afa6cf510
[libc++][functional] P2944R3 (partial): Comparisons for reference_wrapper (reference_wrapper operators only) (#88384)
Implements https://wg21.link/P2944R3 (partially)
Implements https://wg21.link/LWG4071 /
https://cplusplus.github.io/LWG/issue4071 (fixes build failures in the
test suite)
- https://eel.is/c++draft/refwrap.comparisons
2024-05-09 12:48:37 +03:00
Hristo Hristov
9af7f4061b
[libc++][NFC] Fixes a status page note and a minor copy & paste error in a test (#90399)
- Adds a status page note for P3142R0
- Fixes a copy & paste error in tuple protocol for `complex`
2024-04-30 11:31:11 -06:00
Hristo Hristov
9b832b726c
[libc++] Deprecated shared_ptr Atomic Access APIs as per P0718R2 & Implemented P2869R3: Remove Deprecated shared_ptr Atomic Access APIs from C++26 (#87111)
Implements https://wg21.link/P2869R4
Implements deprecations as per https://wg21.link/P0718R2
2024-04-14 14:37:51 +03:00
Xiaoyang Liu
7cafe04e0d
[libc++] P3029R1: Better mdspan's CTAD (#87873)
## Abstract

This pull request implements [P3029R1](https://wg21.link/P3029R1). The
paper discusses the current behavior of `mdspan`'s most common
pointer-indices CTAD, where the `Extents` template parameter is deduced
as `dextents` (dynamic extents), even when passing compile-time constant
values. The author believes this behavior is suboptimal, as it doesn't
take advantage of the compile-time information. The proposed change
suggests deducing static extents if `integral_constant`-like constants
are passed, resulting in more intuitive syntax and less error-prone
code.

## Reference

- [P3029R1](https://wg21.link/P3029R1)
- [Draft C++ Standard: [span.syn]](https://eel.is/c++draft/span.syn)
- [Draft C++ Standard: [mdspan.syn]](https://eel.is/c++draft/mdspan.syn)
2024-04-12 19:25:22 +02:00
Hristo Hristov
7f9f82e3de
[libc++][format] P3142R0: Printing Blank Lines with println (#87277)
Implements https://wg21.link/P3142R0

Applied retroactively as DR, same as stdlibc++ and MS STL:

https://github.com/orgs/microsoft/projects/1143?pane=issue&itemId=57457187
2024-04-06 21:52:52 +03:00
Hristo Hristov
a834436099
[libc++] P2872R3: Remove `wstring_convert` From C++26 (#87100)
Implements: https://wg21.link/P2872R3
2024-04-05 22:04:07 +03:00
Hristo Hristov
fb635be0b8
[libc++] P2867R1: Remove Deprecated strstreams From C++26 (#87107)
Implements: https://wg21.link/P2867R2

---------

Co-authored-by: Hristo Hristov <zingam@outlook.com>
2024-04-04 06:03:00 +03:00
Louis Dionne
d83233f597
[libc++] Mark some recent LWG issues and papers as done (#87502)
Justifications:
- LWG3950: Done in #66206
- LWG3975: Wording changes only
- LWG4011: Wording changes only
- LWG4030: Wording changes only
- LWG4043: Wording changes only
- LWG3036 and P2875R4: We implemented neither, but the latter reverts
the former, so now we implement both without doing anything!
2024-04-03 13:50:55 -04:00
Louis Dionne
b699a9ba11
[libc++] Update status page after the Tokyo meeting (#87395) 2024-04-03 08:21:11 -04:00
Hristo Hristov
716a23c412
[libc++][NFC] Status page: fix minor formatting issues (#83969)
Fixes several minor formatting issues and omissions I introduced on the
status pages in previous patches.
2024-03-06 14:09:26 +02:00
Hristo Hristov
80f9458cf3
[libc++][sstream] P2495R3: Interfacing stringstreams with string_view (#80552)
Implements P2495R3 <https://wg21.link/P2495R3>
- https://eel.is/c++draft/version.syn#headerref:%3csstream%3e
- https://eel.is/c++draft/stringbuf
- https://eel.is/c++draft/stringbuf.general
- https://eel.is/c++draft/stringbuf.cons
- https://eel.is/c++draft/stringbuf.members
- https://eel.is/c++draft/istringstream
- https://eel.is/c++draft/istringstream.general
- https://eel.is/c++draft/istringstream.cons
- https://eel.is/c++draft/istringstream.members
- https://eel.is/c++draft/ostringstream
- https://eel.is/c++draft/ostringstream.general
- https://eel.is/c++draft/ostringstream.cons
- https://eel.is/c++draft/ostringstream.members
- https://eel.is/c++draft/stringstream
- https://eel.is/c++draft/stringstream.general
- https://eel.is/c++draft/stringstream.cons
- https://eel.is/c++draft/stringstream.members

References:
- https://eel.is/c++draft/string.streams
2024-03-05 08:49:49 +02:00
Hristo Hristov
2ea5d167ae
[libc++][complex] P2819R2: Add tuple protocol to complex (#79744)
Implements: P2819R2 <https://wg21.link/P2819R2>
- https://eel.is/c++draft/utilities#concept:tuple-like
- https://eel.is/c++draft/complex.syn
- https://eel.is/c++draft/complex.tuple

---------

Co-authored-by: Zingam <zingam@outlook.com>
2024-02-19 09:56:06 +02:00
Hristo Hristov
27e67cdb31
Reland: [libc++][format] P2637R3: Member visit (std::basic_format_arg) #76449 (#79032)
Deleted the offending test case.


`libcxx/test/std/utilities/format/format.arguments/format.arg/visit.return_type.pass.cpp`
lines: 134-135:   
>   test<Context, bool, long>(true, 192812079084L);
     test<Context, bool, long>(false, 192812079084L);
     
 Relands: https://github.com/llvm/llvm-project/pull/76449
Reverted in:
02f95b7751

---------

Co-authored-by: Zingam <zingam@outlook.com>
2024-01-29 20:57:12 +02:00
Petr Hosek
02f95b7751 Revert "[libc++][format] P2637R3: Member visit (std::basic_format_arg) (#76449)"
This reverts commit 7d9b5aa65b09126031e1c2903605a7d34aea4bc1 since
std/utilities/format/format.arguments/format.arg/visit.return_type.pass.cpp
is failing on Windows when building with Clang-cl.
2024-01-22 17:23:05 +00:00
Hristo Hristov
03c19e91e8
[libc++][numeric] P0543R3: Saturation arithmetic (#77967)
Implements: https://wg21.link/P0543R3
- https://eel.is/c++draft/numeric.sat

Additional references:
- Division: https://eel.is/c++draft/expr.mul#4
- Arithmetic conversions: https://eel.is/c++draft/expr.arith.conv#1
- Clang builtins:
https://clang.llvm.org/docs/LanguageExtensions.html#builtin-functions

Depends on: https://github.com/llvm/llvm-project/pull/78086

---------

Co-authored-by: Zingam <zingam@outlook.com>
Co-authored-by: Mark de Wever <zar-rpg@xs4all.nl>
2024-01-22 06:57:45 +02:00