Implement
- LWG4053 Unary call to `std::views::repeat` does not decay the argument
- LWG4054 Repeating a `repeat_view` should repeat the view
Signed-off-by: yronglin <yronglin777@gmail.com>
## Abstract
This pull request converts the `operator()` of all CPOs and niebloids
related to C++23 ranges to `static`.
## Motivation
In `libc++`, CPOs and niebloids are implemented as function objects.
Currently, the `operator()` for such a function object is a
`const`-qualified member function. This means that even if the function
object is has no data members, an extra register is used to pass in the
`this` pointer when calling `operator()`, unless the compiler can inline
the function call. Declaraing `operator()` as `static` would optimize
away the unnecessary `this` pointer passing for stateless function
objects, since there is no object instance state that needs to be
accessed.
## Reference
- [P1169R4: static `operator()`](https://wg21.link/P1169R4)
Originally, we used __libcpp_verbose_abort to handle assertion failures.
That function was declared from all public headers. Since we don't use
that mechanism anymore, we don't need to declare __libcpp_verbose_abort
from all public headers, and we can clean up a lot of unnecessary
includes.
This patch also moves the definition of the various assertion categories
to the <__assert> header, since we now rely on regular IWYU for these
assertion macros.
rdar://105510916
We recently noticed that the unwrap_iter.h file was pushing macros, but
it was pushing them again instead of popping them at the end of the
file. This led to libc++ basically swallowing any custom definition of
these macros in user code:
#define min HELLO
#include <algorithm>
// min is not HELLO anymore, it's not defined
While investigating this issue, I noticed that our push/pop pragmas were
actually entirely wrong too. Indeed, instead of pushing macros like
`move`, we'd push `move(int, int)` in the pragma, which is not a valid
macro name. As a result, we would not actually push macros like `move`
-- instead we'd simply undefine them. This led to the following code not
working:
#define move HELLO
#include <algorithm>
// move is not HELLO anymore
Fixing the pragma push/pop incantations led to a cascade of issues
because we use identifiers like `move` in a large number of places, and
all of these headers would now need to do the push/pop dance.
This patch fixes all these issues. First, it adds a check that we don't
swallow important names like min, max, move or refresh as explained
above. This is done by augmenting the existing
system_reserved_names.gen.py test to also check that the macros are what
we expect after including each header.
Second, it fixes the push/pop pragmas to work properly and adds missing
pragmas to all the files I could detect a failure in via the newly added
test.
rdar://121365472
The tag name was long for an ABI tag. The name was misleading too, the
tag is first introduced in LLVM 18 in 2024 and not in 2023.
---------
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
fixes#70506
The detailed problem description is in #70506
The original proposed fix was to remove `[[no_unique_address]]` except
when `_Tp` is empty.
Edit:
After the discussion in the comments below, the new fix here is to
remove the `[[no_unique_address]]` from `movable_box` in the cases where
we need to add our own assignment operator, which has contains the
problematic `construct_at`
