`__debug_less` ends up running the comparator up-to-twice per comparison,
because whenever `(x < y)` it goes on to verify that `!(y < x)`.
This breaks the strict "Complexity" guarantees of algorithms like
`inplace_merge`, which we test in the test suite. So, just skip the
complexity assertions in debug mode.
Differential Revision: https://reviews.llvm.org/D101677
This patch gets rid of technical debt around std::pointer_safety which,
I claim, is entirely unnecessary. I don't think anybody has used
std::pointer_safety in actual code because we do not implement the
underlying garbage collection support. In fact, P2186 even proposes
removing these facilities entirely from a future C++ version. As such,
I think it's entirely fine to get rid of complex workarounds whose goals
were to avoid breaking the ABI back in 2017.
I'm putting this up both to get reviews and to discuss this proposal for
a breaking change. I think we should be comfortable with making these
tiny breaks if we are confident they won't hurt anyone, which I'm fairly
confident is the case here.
Differential Revision: https://reviews.llvm.org/D100410
A status page for libc++'s Format library. The page is inspired by
@zoecarver's Ranges status page.
Differential Revision: https://reviews.llvm.org/D101085
This nasty patch rewrites the tuple constructors to match those defined
by the Standard. We were previously providing several extensions in those
constructors - those extensions are removed by this patch.
The issue with those extensions is that we've had numerous bugs filed
against us over the years for problems essentially caused by them. As a
result, people are unable to use tuple in ways that are blessed by the
Standard, all that for the perceived benefit of providing them extensions
that they never asked for.
Since this is an API break, I communicated it in the release notes.
I do not foresee major issues with this break because I don't think the
extensions are too widely relied upon, but we can ship it and see if we
get complaints before the next LLVM release - that will give us some
amount of information regarding how much use these extensions have.
Differential Revision: https://reviews.llvm.org/D96523
Implements parts of:
* P0896R4 The One Ranges Proposal
Depends on D99855.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D99863
This is the initial patch to implement ranges in libc++.
Implements parts of:
- P0896R4 One Ranges Proposal
- P1870 forwarding-range is too subtle
- LWG3379 in several library names is misleading
Reviewed By: ldionne, #libc, cjdb, zoecarver, Quuxplusone
Differential Revision: https://reviews.llvm.org/D90999
This patch fixes LWG2874. It is based on the original patch by Zoe Carver
originally uploaded at D81417.
Differential Revision: https://reviews.llvm.org/D81417
Implements parts of:
* P0896R4 The One Ranges Proposal
* LWG3446 `indirectly_readable_traits` ambiguity for types with both `value_type` and `element_type`
Depends on D99141.
Differential Revision: https://reviews.llvm.org/D99461
The added documents have two tables: 1 containing links to issues and papers related to ranges. And the other contains most of the sections from the One Ranges Proposal, with their dependencies linked. This will allow us to assign work that can be done in parallel.
Differential Revision: https://reviews.llvm.org/D100393
These [[nodiscard]] annotations are added as a conforming extension;
it's unclear whether the paper will actually be adopted and make them
mandatory, but they do seem like good ideas regardless.
https://isocpp.org/files/papers/D2351R0.pdf
This patch implements the paper's effect on:
- std::to_integer, std::to_underlying
- std::forward, std::move, std::move_if_noexcept
- std::as_const
- std::identity
The paper also affects (but libc++ does not yet have an implementation of):
- std::bit_cast
Differential Revision: https://reviews.llvm.org/D99895
After this patch, we can use `--param std=c++20` even if the compiler only
supports -std=c++2a. The test suite will handle that for us. The only Lit
feature that isn't fully baked will always be the "in development" one,
since we don't know exactly what year the standard will be ratified in.
This is another take on https://reviews.llvm.org/D99789.
Differential Revision: https://reviews.llvm.org/D100210
The document has the following updates:
- Rename 'feature test' to 'feature-test', the latter is the spelling
used in the Standard.
- Add information how an ABI list can be downloaded from Buildkite.
Differential Revision: https://reviews.llvm.org/D99290
LWG3175 identifies that the `common_reference` requirement for
`swappable_with` is over-constraining and doesn't need to concern itself
with cv- or reference qualifiers.
Differential Revision: https://reviews.llvm.org/D99817
As mandated by the Standard's various synopses, e.g. [iterator.synopsis].
Searching the TeX source for '#include' is a good way to find all of these
mandates.
The new tests are all autogenerated by utils/generate_header_inclusion_tests.py.
I was SHOCKED by how many mandates there are, and how many of them
libc++ wasn't conforming with.
Differential Revision: https://reviews.llvm.org/D99309
* `std::predicate`
* `std::relation`
* `std::equivalence_relation`
* `std::strict_weak_order`
Implements parts of:
- P0898R3 Standard Library Concepts
- P1754 Rename concepts to standard_case for C++20, while we still can
Differential Revision: https://reviews.llvm.org/D96477
These variables were introduced during early work on the runtimes build
but were obsoleted by {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_LIBRARY_DIR.
Differential Revision: https://reviews.llvm.org/D99697
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.
This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.
It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.
Differential Revision: https://reviews.llvm.org/D97572
This patch changes the variant even in pre-C++2b.
It should not break anything, only allow use cases that didn't work previously.
Notes:
`__as_variant` is used in `__visitation::__variant::__visit_alt`, but I haven't used it in `__visitation::__variant::__visit_alt_at`.
That's because it is used only in `__visit_value_at`, which in turn is always used on variant specializations (that's in comparison operators).
* https://wg21.link/P2162
Reviewed By: ldionne, #libc, Quuxplusone
Differential Revision: https://reviews.llvm.org/D97394
Refresh the existing paragraphs on building in MSVC configurations,
add a sample of one working configuration for MinGW, and add more
details on what's necessary to run the tests these days.
Differential Revision: https://reviews.llvm.org/D97166
This patch ensures that SFINAE is used to delete assignment operators in pair and tuple based on issue 2729.
Differential Review: https://reviews.llvm.org/D62454
This patch implements 2802. Requires _Deleter to have call operator and be move constructible. Based on D62233.
Refs PR37637.
Differential Revision: https://reviews.llvm.org/D62274
Arthur O'Dwyer