Make sure we provide the correct It::difference_type member and update
the tests and synopses to be accurate.
Supersedes D102657 and D103101 (thanks to the original authors).
Differential Revision: https://reviews.llvm.org/D103273
C++17 deprecated std::iterator and removed it as a base class for all
iterator adaptors. We implement that change, but we still provide a way
to inherit from std::iterator in the few cases where doing otherwise
would be an ABI break.
Supersedes D101729 and the std::iterator base parts of D103101 and D102657.
Differential Revision: https://reviews.llvm.org/D103171
Implements part of P0896 'The One Ranges Proposal'.
Implements [range.iter.op.prev].
Depends on D102563.
Differential Revision: https://reviews.llvm.org/D102564
Implements part of P0896 'The One Ranges Proposal'.
Implements [range.iter.op.next].
Depends on D101922.
Differential Revision: https://reviews.llvm.org/D102563
Not only do we conscientiously avoid using `__wrap_iter` for non-contiguous
iterators (in vector, string, span...) but also we make the assumption
(in regex) that `__wrap_iter<_Iter>` is contiguous for all `_Iter`.
So `__wrap_iter<reverse_iterator<int*>>` should be considered IFNDR,
and every `__wrap_iter` should correctly advertise contiguity in C++20.
Drive-by simplify some type traits.
Reviewed as part of https://reviews.llvm.org/D102781
This is a rough reapplication of the change that fixed std::to_address
to avoid relying on element_type (da456167). It is somewhat different
because the fix to avoid breaking Clang (which caused it to be reverted
in 347f69c55) was a bit more involved.
Differential Revision: https://reviews.llvm.org/D101638
This reverts commit da456167, which broke the Clang build. I'm able to
reproduce it but I want to give myself a bit more time to investigate.
Differential Revision: https://reviews.llvm.org/D101638
This reverts a large chunk of http://reviews.llvm.org/D15862 ,
and also fixes bugs in `insert`, `append`, and `assign`, which are now regression-tested.
(Thanks to Tim Song for pointing out the bug in `append`!)
Before this patch, we did a special dance in `append`, `assign`, and `insert`
(but not `replace`). All of these require the strong exception guarantee,
even when the user-provided InputIterator might have throwing operations.
The naive way to accomplish this is to construct a temporary string and
then append/assign/insert from the temporary; i.e., finish all the potentially
throwing and self-inspecting InputIterator operations *before* starting to
modify self. But this is slow, so we'd like to skip it when possible.
The old code (D15682) attempted to check that specific iterator operations
were nothrow: it assumed that if the iterator operations didn't throw, then
it was safe to iterate the input range multiple times and therefore it was
safe to use the fast-path non-naive version. This was wrong for two reasons:
(1) the old code checked the wrong operations (e.g. checked noexceptness of `==`,
but the code that ran used `!=`), and (2) the conversion of value_type to char
could still throw, or inspect the contents of self.
The new code is much simpler, although still much more complicated than it
really could be. We'll likely revisit this codepath at some point, but for now
this patch suffices to get it passing all the new regression tests.
The added tests all fail before this patch, and succeed afterward.
See https://quuxplusone.github.io/blog/2021/04/17/pathological-string-appends/
Differential Revision: https://reviews.llvm.org/D98573
Implements parts of:
* P0896R4 The One Ranges Proposal`
Depends on D100073.
Reviewed By: ldionne, zoecarver, #libc
Differential Revision: https://reviews.llvm.org/D100080
That was originally committed in 04733181b513 and then reverted in
a9f11cc0d965 because it broke several people.
The problem was a missing include of __iterator/concepts.h, which has now
been fixed.
Differential Revision: https://reviews.llvm.org/D100073
Implements parts of:
* P0896R4 The One Ranges Proposal`
Depends on D99873.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D100073
Implements parts of:
* P0896R4 The One Ranges Proposal
Depends on D99855.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D99863
Based on D100682 and D99855.
(Note: I originally was going to just make this part of D99855, but I decided not to because this patch moves lots of unrelated code around, and I didn't want to make D99855 harder to review because of unrelated code-changes/moves.)
Differential Revision: https://reviews.llvm.org/D100686
* adds `iterator_traits` specialisation that supports all expected
member aliases except for `pointer`
* adds `iterator_traits` specialisations for iterators that meet the
legacy iterator requirements but might lack multiple member aliases
* makes pointer `iterator_traits` specialisation require objects
Depends on D99854.
Differential Revision: https://reviews.llvm.org/D99855
The `iterator_traits` patch became too large for a concise review, so
the "bloat" —as it were— was moved into this patch. Also tests most
C++[98,17] iterator types to confirm backwards compatibility is
successful (regex iterators are intentionally not present, but directory
iterators are due to a peculiar error encountered while patching
`iterator_traits`).
Depends on D99461.
Differential Revision: https://reviews.llvm.org/D99854
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
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
The container headers don't need to include <functional> for any other reason
(or at least, they wouldn't if we moved `less` and `equal_to` out of <functional>),
so let's put `__libcpp_erase_if_container` somewhere that's common to the
containers but outside of <functional>.
Also, calling `std::erase_if(c, pred)` should not trigger ADL.
Differential Revision: https://reviews.llvm.org/D99043
- Implement C++20's changes to `reverse_iterator`, so that it won't be
accidentally counted as a contiguous iterator in C++20 mode.
- Implement C++20's changes to `move_iterator` as well.
- `move_iterator` should not be contiguous. This fixes a bug where
we optimized `std::copy`-of-move-iterators in an observable way.
Add a regression test for that bugfix.
- Add libcxx tests for `__is_cpp17_contiguous_iterator` of all relevant
standard iterator types. Particularly check that vector::iterator
is still considered contiguous in all C++ modes, even C++03.
After this patch, there continues to be no supported way to write your
own iterator type in C++17-and-earlier such that libc++ will consider it
"contiguous"; however, we now fully support the C++20 approach (in C++20
mode only). If you want user-defined contiguous iterators in C++17-and-earlier,
libc++'s position is "please upgrade to C++20."
Differential Revision: https://reviews.llvm.org/D94807
In addition to making the code a lot easier to grasp by localizing many
helper functions to the only file where they are actually needed, this
will allow creating helper functions that depend on allocator_traits
outside of <memory>.
This is done as part of implementing array support in allocate_shared,
which requires non-trivial array initialization algorithms that would be
better to keep out of <memory> for sanity. It's also a first step towards
splitting up our monolithic headers into finer grained ones, which will
make it easier to reuse functionality across the library. For example,
it's just weird that we had to define `addressof` inside <type_traits>
to avoid circular dependencies -- instead it's better to implement those
in true helper headers.
Differential Revision: https://reviews.llvm.org/D93074
The interesting change here is that we no longer consider `__convert_to_integral`
an ADL customization point for the user's types. I think the new behavior
is defensible. The old behavior had come from D7449, where Marshall explicitly
said "people can't define their own [`__convert_to_integral` overloads]."
Differential Revision: https://reviews.llvm.org/D92814
