C++ constexpr allows a non-constant-expresssion lvalue to be used in a constant expression if it's not subject to lvalue-to-rvalue conversion. Subtly, this means you can make a constant-expression copy of a non-constant-expression object of empty type since the copy constructor doesn't perform lvalue-to-rvalue conversion. MSVC has had bugs with this usage forever, which will hopefully finally be mashed implementing C++23's relaxation on the use of pointers and references in constant expressions.
There's no need for this particular test to use this particular constexpr feature, we can simply make the predicates constant expressions.
Differential Revision: https://reviews.llvm.org/D141336
Per our policy, the latest released AppleClang has been 14 for a while,
so libc++ is removing support for AppleClang 13. Our CI bots have been
moved to AppleClang 14 a few weeks ago.
Differential Revision: https://reviews.llvm.org/D138685
We currently call a lot of functions with the same list of types. To avoid forgetting any of them, this patch adds type_lists and utilities for it. Specifically, it adds
- `type_list` - This is just a list of types
- `concatenate` - This allows concatenating type_lists
- `for_each` - Iterate over a type_list
Reviewed By: ldionne, #libc
Spies: jloser, EricWF, libcxx-commits
Differential Revision: https://reviews.llvm.org/D137476
This mirrors what we have done in the classic algorithms
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D137186
Instead of using `reverse_iterator`, share the optimization between the 4 algorithms. The key observation here that `memmove` applies to both `copy` and `move` identically, and to their `_backward` versions very similarly. All algorithms now follow the same pattern along the lines of:
```
if constexpr (can_memmove<InIter, OutIter>) {
memmove(first, last, out);
} else {
naive_implementation(first, last, out);
}
```
A follow-up will delete `unconstrained_reverse_iterator`.
This patch removes duplication and divergence between `std::copy`, `std::move` and `std::move_backward`. It also improves testing:
- the test for whether the optimization is used only applied to `std::copy` and, more importantly, was essentially a no-op because it would still pass if the optimization was not used;
- there were no tests to make sure the optimization is not used when the effect would be visible.
Differential Revision: https://reviews.llvm.org/D130695
compressed_pair is widely used in the library, but most of the uses don't use the tuple parts. To avoid including <tuple> everywhere, use the forward declaration instead in compressed_pair.h
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D133331
Adding `[[nodiscard]]` to functions is a conforming extension and done extensively in the MSVC STL.
Reviewed By: ldionne, EricWF, #libc
Spies: #libc_vendors, cjdb, mgrang, jloser, libcxx-commits
Differential Revision: https://reviews.llvm.org/D128267
When we ship LLVM 16, <ranges> won't be considered experimental anymore.
We might as well do this sooner rather than later.
Differential Revision: https://reviews.llvm.org/D132151
Also fix `ranges::stable_sort` and `ranges::inplace_merge` to support
proxy iterators now that their internal implementations can correctly
dispatch `rotate`.
Differential Revision: https://reviews.llvm.org/D130758
The return value for both of these algorithms is specified as
```
`{last, result - N}` for the overloads in namespace `ranges`.
```
But the current implementation instead returns `{first, result - N}`.
Also add both algorithms to the relevant "robust" tests.
Differential Revision: https://reviews.llvm.org/D130968
- for all algorithms taking more than one range, add a `robust` test to
check the case where the ranges have different value types and the
given projections are different, with each projection applying to
a different value type;
- fix `ranges::include` to apply the correct projection to each range.
Differential Revision: https://reviews.llvm.org/D130515
This adds a C++20-version of `reverse_iterator` which doesn't SFINAE away the operators for use inside the classic STL algorithms. Pre-C++20 `_AlgRevIter` is just an alias for `reverse_iterator`.
Reviewed By: var-const, #libc
Spies: huixie90, libcxx-commits
Differential Revision: https://reviews.llvm.org/D128864
This patch rewords the static assert diagnostic output. Failing a
_Static_assert in C should not report that static_assert failed. This
changes the wording to be more like GCC and uses "static assertion"
when possible instead of hard coding the name. This also changes some
instances of 'static_assert' to instead be based on the token in the
source code.
Differential Revision: https://reviews.llvm.org/D129048
Looks like we again are going to have problems with libcxx tests that
are overly specific in their dependency on clang's diagnostics.
This reverts commit 6542cb55a3eb115b1c3592514590a19987ffc498.
This patch is basically the rewording of the static assert statement's
output(error) on screen after failing. Failing a _Static_assert in C
should not report that static_assert failed. It’d probably be better to
reword the diagnostic to be more like GCC and say “static assertion”
failed in both C and C++.
consider a c file having code
_Static_assert(0, "oh no!");
In clang the output is like:
<source>:1:1: error: static_assert failed: oh no!
_Static_assert(0, "oh no!");
^ ~
1 error generated.
Compiler returned: 1
Thus here the "static_assert" is not much good, it will be better to
reword it to the "static assertion failed" to more generic. as the gcc
prints as:
<source>:1:1: error: static assertion failed: "oh no!"
1 | _Static_assert(0, "oh no!");
| ^~~~~~~~~~~~~~
Compiler returned: 1
The above can also be seen here. This patch is about rewording
the static_assert to static assertion.
Differential Revision: https://reviews.llvm.org/D129048
The return type was specified incorrectly for proxy iterators that
define `reference` to be a class that implicitly converts to
`value_type`. `__iter_move` would end up returning an object of type
`reference` which would then implicitly convert to `value_type`; thus,
the function will return a `value_type&&` rvalue reference to the local
temporary.
Differential Revision: https://reviews.llvm.org/D130197
