Note that most changes to `strings` and `views.span` from the One Ranges
Proposal are no longer applicable:
- free `begin` and `end` functions taking `basic_string_view` and `span`
were removed by [P1870](http://wg21.link/p1870);
- `span::const_iterator` was removed by [LWG3320](https://cplusplus.github.io/LWG/lwg-defects.html#3320).
Reviewed By: #libc, Quuxplusone, ldionne
Differential Revision: https://reviews.llvm.org/D118687
This includes an experimental workaround for
LWG3664 "LWG3392 broke std::ranges::distance(a, a+3)",
but the workaround may be incomplete, I'm not sure.
This should be re-audited when LWG3664 is actually adopted,
to see if we need to change anything about our implementation.
See also https://github.com/microsoft/STL/pull/2500
Differential Revision: https://reviews.llvm.org/D117940
Each "Nothing To Do" issue only changed nits in the English wording,
not anything to do with the code.
Each "Complete" issue was completed already, as far as I can tell.
I tried to err on the side of caution: I didn't mark a few issues
whose P/Rs were very invasive and would take time to verify, and I
didn't mark a lot of issues involving features we haven't even started
yet.
Differential Revision: https://reviews.llvm.org/D117960
The tests for these are just copy-pasted from the tests for std::{strong,weak,partial}_order,
and then I added an extra clause in each (test_2()) to test the stuff that's not just the same
as std::*_order.
This also includes the fix for https://wg21.link/LWG3465 (which falls naturally out of the
"you must write it three times" style, but I've added test cases for it also).
There is an action item here to go back and give good diagnostics for SFINAE failures
in these CPOs. I've filed this as https://github.com/llvm/llvm-project/issues/53456 .
Differential Revision: https://reviews.llvm.org/D111514
Fixed in counted_iterator and transform_view::iterator.
The LWG issue also affected elements_view::iterator, but we haven't
implemented that one yet, and whoever does implement it will get
the fix for free if they just follow the working draft's wording.
Drive-by stop calling `.base()` on test iterators in the test,
and improve the transform_view::iterator/sentinel tests.
Differential Revision: https://reviews.llvm.org/D117329
https://cplusplus.github.io/LWG/issue3422
Also add a static_assert to check the "Mandates:" on the
iterator-pair constructor. Oddly, the `InputIterator` parameter
itself is merely preconditioned, not constrained, to satisfy the
input iterator requirements.
Also drive-by rename `init` to `__init`.
Differential Revision: https://reviews.llvm.org/D117962
This adjust the version macro and sets it as completed. All parts of the paper
have been implemented, except for the parts replaced by later papers and
LWG-issues.
Adjusted the synopsis to match the synopsis in the Standard. Not yet
implemented parts of P2216 and P2418 still use the P0645 wording.
Completes:
- P0645 Text Formatting
Depends on D115991
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D115999
This implements the last required formatter specialization.
Completes:
- LWG 3251 Are std::format alignment specifiers applied to string arguments?
- LWG 3340 Formatting functions should throw on argument/format string mismatch in §[format.functions]
- LWG 3540 §[format.arg] There should be no const in basic_format_arg(const T* p)
Implements parts of:
- P0645 Text Formatting
Depends on D114001
Reviewed By: ldionne, vitaut, #libc
Differential Revision: https://reviews.llvm.org/D115988
This properly implements the formatter for floating-point types.
Completes:
- P1652R1 Printf corner cases in std::format
- LWG 3250 std::format: # (alternate form) for NaN and inf
- LWG 3243 std::format and negative zeroes
Implements parts of:
- P0645 Text Formatting
Reviewed By: #libc, ldionne, vitaut
Differential Revision: https://reviews.llvm.org/D114001
Implement LWG3549 by making `view_interface` not inherit from `view_base`. Types
are still views if they have a public and unambiguous derivation from
`view_interface`, so adjust the `enable_view` machinery as such to account for
that.
Differential Revision: https://reviews.llvm.org/D117714
The code in libc++ already satisfy the requirements of LWG-3373. Since
the issue was written to specifically allow the types to be used in
structured bindings, tests have been added to validate the new
requirement.
Implements
LWG-3373 {to,from}_chars_result and format_to_n_result need the "we really mean what we say" wording
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D117337
We didn't support noop_coroutine for GCC in previous conforming patch.
So that GCC couldn't use noop_coroutine() defined in <coroutine>. And
after this patch, GCC should be able to compile the whole <coroutine>
header.
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D116144
Clang is gaining `auto(x)` support in D113393; sadly there
seems to be no feature-test macro for it. Zhihao is opening
a core issue for that macro.
Use `_LIBCPP_AUTO_CAST` where C++20 specifies we should use `auto(x)`;
stop using `__decay_copy(x)` in those places.
In fact, remove `__decay_copy` entirely. As of C++20, it's purely
a paper specification tool signifying "Return just `x`, but it was
perfect-forwarded, so we understand you're going to have to call
its move-constructor sometimes." I believe there's no reason we'd
ever need to do its operation explicitly in code.
This heisenbugs away a test failure on MinGW; see D112214.
Differential Revision: https://reviews.llvm.org/D115686
When P0883R2 was initially implemented in D103769 #pragma clang deprecated didn't exist yet.
We also forgot to cleanup usages in libc++ itself.
This takes care of both.
Differential Revision: https://reviews.llvm.org/D115995
Also:
- refactor out `__voidify`;
- use the `destroy` algorithm internally;
- refactor out helper classes used in tests for `uninitialized_*`
algorithms.
Differential Revision: https://reviews.llvm.org/D115626
Defined in [`specialized.algorithms`](wg21.link/specialized.algorithms).
Also:
- refactor the existing non-range implementation so that most of it
can be shared between the range-based and non-range-based algorithms;
- remove an existing test for the non-range version of
`uninitialized_default_construct{,_n}` that likely triggered undefined
behavior (it read the values of built-ins after default-initializing
them, essentially reading uninitialized memory).
Reviewed By: #libc, Quuxplusone, ldionne
Differential Revision: https://reviews.llvm.org/D115315
Microsoft would like to contribute its implementation of floating-point to_chars to libc++. This uses the impossibly fast Ryu and Ryu Printf algorithms invented by Ulf Adams at Google. Upstream repos: https://github.com/microsoft/STL and https://github.com/ulfjack/ryu .
Licensing notes: MSVC's STL is available under the Apache License v2.0 with LLVM Exception, intentionally chosen to match libc++. We've used Ryu under the Boost Software License.
This patch contains minor changes from Jorg Brown at Google, to adapt the code to libc++. He verified that it works in Google's Linux-based environment, but then I applied more changes on top of his, so any compiler errors are my fault. (I haven't tried to build and test libc++ yet.) Please tell me if we need to do anything else in order to follow https://llvm.org/docs/DeveloperPolicy.html#attribution-of-changes .
Notes:
* libc++'s integer charconv is unchanged (except for a small refactoring). MSVC's integer charconv hasn't been tuned for performance yet, so you're not missing anything.
* Floating-point from_chars isn't part of this patch because Jorg found that MSVC's implementation (derived from our CRT's strtod) was slower than Abseil's. If you're unable to use Abseil or another implementation due to licensing or technical considerations, Microsoft would be delighted if you used MSVC's from_chars (and you can just take it, or ask us to provide a patch like this). Ulf is also working on a novel algorithm for from_chars.
* This assumes that float is IEEE 32-bit, double is IEEE 64-bit, and long double is also IEEE 64-bit.
* I have added MSVC's charconv tests (the whole thing: integer/floating from_chars/to_chars), but haven't adapted them to libcxx's harness at all. (These tests will be available in the microsoft/STL repo soon.)
* Jorg added int128 codepaths. These were originally present in upstream Ryu, and I removed them from microsoft/STL purely for performance reasons (MSVC doesn't support int128; Clang on Windows does, but I found that x64 intrinsics were slightly faster).
* The implementation is split into 3 headers. In MSVC's STL, charconv contains only Microsoft-written code. xcharconv_ryu.h contains code derived from Ryu (with significant modifications and additions). xcharconv_ryu_tables.h contains Ryu's large lookup tables (they were sufficiently large to make editing inconvenient, hence the separate file). The xmeow.h convention is MSVC's for internal headers; you may wish to rename them.
* You should consider separately compiling the lookup tables (see https://github.com/microsoft/STL/issues/172 ) for compiler throughput and reduced object file size.
* See https://github.com/StephanTLavavej/llvm-project/commits/charconv for fine-grained history. (If necessary, I can perform some rebase surgery to show you what Jorg changed relative to the microsoft/STL repo; currently that's all fused into the first commit.)
Differential Revision: https://reviews.llvm.org/D70631
