Fixes#105260
This patch applies the change as a DR to C++20. The rationale is that
the paper is more like a bug fix. It does not introduce new features, it
simply changes an existing behaviour (as a bug fix). MSVC STL DRed this
paper to C++20 as well.
This test was deadlocking on my machine.
It seems to me the intention of `in_async.wait(...)` was to wait for the
value to be set to true, which requires a call of `wait(false)` (waits
if value matches argument).
~As a drive by change scoped_lock to unique_lock, since there shouldn't
be any functional difference between the two in this test.~
I've addressed the issues with the `in_async` by switching to a
condition variable instead, since my first attempt at fixing this with
`in_async` wasn't sufficient.
Fixes#108624
This allows `flat_map::insert(Iter, Iter)` to directly forward to
underlying containers' `insert(Iter, Iter)`, instead of inserting one
element at a time, when input models "product iterator". atm,
`flat_map::iterator` and `zip_view::iterator` are "product iterator"s.
This gives about almost 10x speed up in my benchmark with -03 (for both
before and after)
```cpp
Benchmark Time CPU Time Old Time New CPU Old CPU New
-----------------------------------------------------------------------------------------------------------------------------------------------
flat_map::insert_product_iterator_flat_map/32 -0.5028 -0.5320 149 74 149 70
flat_map::insert_product_iterator_flat_map/1024 -0.8617 -0.8618 3113 430 3112 430
flat_map::insert_product_iterator_flat_map/8192 -0.8877 -0.8877 26682 2995 26679 2995
flat_map::insert_product_iterator_flat_map/65536 -0.8769 -0.8769 226235 27844 226221 27841
flat_map::insert_product_iterator_zip/32 -0.5844 -0.5844 162 67 162 67
flat_map::insert_product_iterator_zip/1024 -0.8754 -0.8754 3427 427 3427 427
flat_map::insert_product_iterator_zip/8192 -0.8934 -0.8934 28134 3000 28132 3000
flat_map::insert_product_iterator_zip/65536 -0.8783 -0.8783 229783 27960 229767 27958
OVERALL_GEOMEAN -0.8319 -0.8332 0 0 0 0
```
---------
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
This patch is very similar to #134819 in nature. Before this patch, we
were dereferencing pointers to objects which were never constructed. Now
we always assume that nodes store `pair<const KeyT, ValueT>` for
unordered_maps instead, as they actually do.
If the creation of a thread fails, this causes an idle loop that will
never end because the thread wasn't started in the first place.
This also adds a test for the regression reported in #125433 to make
sure we're not reintroducing it later.
Fixes#125428
This patch addresses several implementation issues in `bitset`'s
conversion functions `to_ullong` and `to_ulong`, and refactors its
converting constructor `__bitset(unsigned long long __v)` to a more
generic and elegant implementation.
`template <class = int>` is also added to our implementations to avoid
an ambiguity between the libc's version and our version when both are
visible.
This avoids including `<stdlib.h>` in `<math.h>`.
Previously, the segmented iterator optimization was limited to `std::{for_each, for_each_n}`. This patch
extends the optimization to `std::ranges::for_each` and `std::ranges::for_each_n`, ensuring consistent
optimizations across these algorithms. This patch first generalizes the `std` algorithms by introducing
a `Projection` parameter, which is set to `__identity` for the `std` algorithms. Then we let the `ranges`
algorithms to directly call their `std` counterparts with a general `__proj` argument. Benchmarks
demonstrate performance improvements of up to 21.4x for ``std::deque::iterator`` and 22.3x for
``join_view`` of ``vector<vector<char>>``.
Addresses a subtask of #102817.
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>
Unconditional evaluation of `char_traits<_CharT>::length(__str)` is problematic, because it causes
UB when `__str` points to a non-null-terminated array. We should only call `length` (currently, in
`basic_string_view`'s constructor) when `__n == npos` per [bitset.cons]/8.
Drive-by change: Reduction of conditional compilation, given that
- both `basic_string_view<_CharT>::size_type` and `basic_string<_CharT>::size_type` must be
`size_t`, and thus
- both `basic_string_view<_CharT>::npos` and `basic_string<_CharT>::npos` must be `size_t(-1)`.
For the type sameness in the standard wording, see:
- [string.view.template.general]
- [basic.string.general]
- [allocator.traits.types]/6
- [default.allocator.general]/1
Fixes#143684
This was part of https://wg21.link/p0355r7, but apparently never
implemented.
---------
Co-authored-by: MarcoFalke <*~=`'#}+{/-|&$^_@721217.xyz>
Co-authored-by: Hristo Hristov <zingam@outlook.com>
This patch includes __fwd/span.h in <mdspan> so that we get the
declaration of dynamic_extent inside <mdspan>. We also clean up quite a
few tests that were manually included <span> for dynamic_extent.
This is based on feedback from #142693.
Reviewers: philnik777, ldionne
Reviewed By: philnik777
Pull Request: https://github.com/llvm/llvm-project/pull/142925
This is brought up in the LWG reflector. We currently call `reserve` if
the underlying container has one. But the spec does not specify what
`reserve` should do for Sequence Container. So in theory if the
underlying container is user defined type and it can have a function
called `reserve` which does something completely different.
The fix is to just call `reserve` for STL containers if it has one
See discussion in https://cplusplus.github.io/LWG/issue4239
std::flat_map<std::string, int, std::less<>> m;
m.try_emplace("abc", 5); // hard error
The reason is that we specify in 23.6.8.7 [flat.map.modifiers]/p21
the effect to be as if `ranges::upper_bound` is called.
`ranges::upper_bound` requires indirect_strict_weak_order, which
requires the comparator to be invocable for all combinations. In this
case, it requires
const char (&)[4] < const char (&)[4]
to be well-formed, which is no longer the case in C++26 after
https://wg21.link/P2865R6.
This patch uses `std::upper_bound` instead.
Currently, when the string shrink into the SSO buffer, the `__rep_.__s`
member isn't activated before the `traits_type::copy` call
yet, so internal `__builtin_memmove` call writing to the buffer causes
constant evaluation failure. The existing test coverage seems a bit
defective and doesn't cover this case - `shrink_to_fit` is called on the
copy of string after erasure, not the original string object.
This PR reorders the `__set_short_size` call, which starts the lifetime
of the SSO buffer, before the copy operation. Test coverage is achieved
by calling `shrink_to_fit` on the original erased string.
The current implementation of `forward_list::resize` does not meet the
strong exception safety guarantee required by [forward.list.modifiers]:
If an exception is thrown by any of these member functions there is no
effect on the container.
This patch refactors `resize()` to provide strong exception safety and
introduces additional tests to validate the strong exception guarantees
for other `forward_list` modifiers.
Fixes#118366.
`common_reference` isn't an exception for [meta.rqmts]/4, so it's better
to disallow users to specialize it.
`indirectly_readable.compile.pass.cpp` was a bit problematic. It
attempted to opt-out common reference type in some wrong ways. Also, the
standard effectively forbids opting-out common reference type for `T&`
and `T&&`. This patch removes and adjusts some problematic cases.
---------
Co-authored-by: Nikolas Klauser <nikolasklauser@berlin.de>
#109028 caused `sizeof` to be sometimes applied to function reference
types, which makes a program ill-formed. This PR handles reference types
by specializations to prevent such bogus `sizeof` expression to be
instantiated.
Fixes#142118.
Currently, libc++'s `<tuple>` is using the deprecated
`__reference_binds_to_temporary` intrinsic. This PR starts to use
`__reference_constructs_from_temporary` if possible.
It seems that `__reference_constructs_from_temporary` should be used via
an internal type traits provided in
`<__type_traits/reference_constructs_from_temporary.h>`. But given the
old intrinsic was directly used, this PR doesn't switch to the current
convention yet.
P2255R2 is related. Although the paper indicated that constructors of
`tuple` should be deleted in such a case.
---------
Co-authored-by: Nikolas Klauser <nikolasklauser@berlin.de>
Fixes#135351
This PR update CATD guides to associative containers (`std::map`,
`std::multimap`, `std::unordered_map`, `std::unordered_multimap`,
`std::flat_map`, `std::flat_multimap`).
- Updated template alias for deduction guides for the relevant
associative containers.
- Added a new test to verify the deduction guides with `std::map`,
`std::multimap`, `std::unordered_map`, `std::unordered_multimap`,
`std::flat_map`, `std::flat_multimap`.
The underlying bug in vcruntime [1] has been fixed in the latest version
of MSVC (released two weeks ago); this will cause the test which is
currently marked XFAIL to start erroring, when it starts passing
unexpectedly.
This version of MSVC may soon start appearing in the Github Actions
runner images used for our CI.
We could try to detect the state of this bug, but in practice, such
detection code would essentially be a copy of this whole test.
Therefore, just mark this test UNSUPPORTED for the MSVC mode builds. If
we at some point require new enough MSVC libraries, we could remove the
marking entirely.
[1]
https://developercommunity.visualstudio.com/t/vcruntime-nothrow-array-operator-new-fal/10373274
This patch enhances the performance of `std::for_each_n` when used with
segmented iterators, leading to significant performance improvements,
summarized in the tables below. This addresses a subtask of
https://github.com/llvm/llvm-project/issues/102817.
This has been introduced by #134819, most likely due to a merge conflict
I didn't resolve properly (I thought I did in that patch what I'm now
doing here).
