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
This was discussed on Discord with the consensus that we should rename the macros.
Reviewed By: ldionne, Mordante, var-const, avogelsgesang, jloser, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D131498
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
Avoid relying on `iterator_traits` and instead deduce the return type of
dereferencing the iterator. Additionally, add a static check to reject
iterators with incorrect `iterator_traits` at compile time.
Differential Revision: https://reviews.llvm.org/D130538
- 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
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
Change the mechanism in `iterator_operations.h` to pass around a generic
policy tag indicating whether an internal function is being invoked from
a "classic" STL algorithm or a ranges algorithm. `IterOps` is now
a template class specialized on the policy tag.
The advantage is that this mechanism is more generic and allows defining
arbitrary conditions in a clean manner.
Also add a few more iterator functions to `IterOps`.
Differential Revision: https://reviews.llvm.org/D129390
- create the headers (but not include them from `<algorithm>`);
- define the niebloid and its member functions with the right signatures
(as no-ops);
- make sure all the right headers are included that are required by each
algorithm's signature;
- update `CMakeLists.txt` and the module map;
- create the test files with the appropriate synopses.
The synopsis in `<algorithm>` is deliberately not updated because that
could be taken as a readiness signal. The new headers aren't included
from `<algorithm>` for the same reason.
Differential Revision: https://reviews.llvm.org/D129549
