The SFINAE isn't required, since the primary `tuple` class already does
the SFINAE checks. This removes a bit of code that was only used for
these constraints.
This also moves the `tuple_element` specialization for `tuple` to
`__fwd/tuple.h` to avoid a dependency on `__tuple/sfinae_helpers.h`
(which should be moved in a follow-up).
#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.
This reverts commit c861fe8a71e64f3d2108c58147e7375cd9314521.
Unfortunately, this use of hidden visibility attributes causes
user-defined specializations of standard-library types to also be marked
hidden by default, which is incorrect. See discussion thread on #131156.
...and also reverts the follow-up commits:
Revert "[libc++] Add explicit ABI annotations to functions from the block runtime declared in <__functional/function.h> (#140592)"
This reverts commit 3e4c9dc299c35155934688184319d391b298fff7.
Revert "[libc++] Make ABI annotations explicit for windows-specific code (#140507)"
This reverts commit f73287e623a6c2e4a3485832bc3e10860cd26eb5.
Revert "[libc++][NFC] Replace a few "namespace std" with the correct macro (#140510)"
This reverts commit 1d411f27c769a32cb22ce50b9dc4421e34fd40dd.
This patch introduces `_LIBCPP_{BEGIN,END}_EXPLICIT_ABI_ANNOTATIONS`,
which allow us to have implicit annotations for most functions, and just
where it's not "hide_from_abi everything" we add explicit annotations.
This allows us to drop the `_LIBCPP_HIDE_FROM_ABI` macro from most
functions in libc++.
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 maps instead, as they actually do. This patch also
allows for significant follow-up simplifications, since
`__node_value_type` and `__container_value_type` are the same type now.
That type trait represents whether move-assigning an object is
equivalent to destroying it and then move-constructing a new one from
the same argument. This will be useful in a few places where we may want
to destroy + construct instead of doing an assignment, in particular
when implementing some container operations in terms of relocation.
This is effectively adding a library emulation of P2786R12's
is_replaceable trait, similarly to what we do for trivial relocation.
Eventually, we can replace this library emulation by the real
compiler-backed trait.
This is building towards #129328.
Recent Clang-21 builds improved the deprecated diagnotics. This
uncovered missing guards in libc++ internally.
Note: This patch should be a separate commit and not merged.
For testing purposes they are combined.
Reviewed as part of #130497.
This set usage of operator& instead of std::addressof seems not be easy
to "abuse". Some seem easy to misuse, like basic_ostream::operator<<,
trying to do that results in compilation errors since the `widen`
function is not specialized for the hijacking character type. Hence
there are no tests.
This is technically not necessary in most cases to prevent issues with ADL,
but let's be consistent. This allows us to remove the libcpp-qualify-declval
clang-tidy check, which is now enforced by the robust-against-adl clang-tidy check.
This patch separates the destroy algorithms from the primitive
construct_at and destroy_at operations, which are conceptually not
algorithms. This makes it easier to start using these destroy algorithms
from upcoming relocation facilities.
As part of this, it also implements `std::destroy_at` for arrays without
relying on the `std::destroy` algorithm, which is conceptually a
higher-level facility.
Changes:
- Carve out sized but input-only ranges for C++23.
- Call `std::move` for related functions when the iterator is possibly input-only.
Fixes#115727
Implementing `constexpr std::stable_sort`. This is part of P2562R1,
tracked via issue #105360.
Closes#119394
Co-authored-by: A. Jiang <de34@live.cn>
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
Currently, places where we call __libcpp_allocate must drop type
information on the ground even when they actually have such information
available. That is unfortunate since some toolchains and system
allocators are able to provide improved security when they know what
type is being allocated.
This is the purpose of http://wg21.link/p2719, where we introduce a new
variant of `operator new` which takes a type in its interface. A
different but related issue is that `std::allocator` does not honor any
in-class `T::operator new` since it is specified to call the global
`::operator new` instead.
This patch closes the gap to make it trivial for implementations that
provide typed memory allocators to actually benefit from that
information in more contexts, and also makes libc++ forward-compatible
with future proposals that would fix the existing defects in
`std::allocator`. It also makes the internal allocation API higher level
by operating on objects instead of operating on bytes of memory.
Since this is a widely-used function and making this a template could
have an impact on debug info sizes, I tried minimizing the number of
templated layers by removing `__do_deallocate_handle_size`, which was
easy to replace with a macro (and IMO this leads to cleaner code).
This disentangles the code which previously had a mix of many #ifdefs, a
non-versioned namespace and a versioned namespace. It also makes it
clearer which parts of <new> are implemented on Windows by including <new.h>.
Put _LIBCPP_NODEBUG on the new allocator trait aliases introduced in
https://github.com/llvm/llvm-project/pull/115654. This prevents a large
increase in the gdb_index size that was introduced by that PR.
While reference comparators are a terrible idea and it's not entirely
clear whether they are supported, fixing the unintended ABI break is
straightforward so we should do it as a first step.
Fixes#118559
This simplifies the implementation a bit, since we don't need a lot of
the `__has_x` classes anymore. We just need two template aliases to
implement the `allocator_traits` aliases now.
This generalizes the algorithm a bit. Unfortunately, we can't make
the call sites cleaner inside std::vector because the arguments being
passed can all be fancy pointers, which may not be contiguous iterators.
`__shared_count` is used in a few places where `shared_ptr` isn't. This
avoids a bunch of transitive includes needed for the implementation of
`shared_ptr` in these places.
We can define some of these aliases without having to include the system
<stddef.h> and there doesn't seem to be much of a reason we shouldn't do
it this way.
This improves the diagnostics a bit by using `enable_if_t` which clang
is aware of, instead of a custom SFINAE class, as well as writing the
functions in a more canonical style.
As a drive-by this also makes `__is_{,un}bounded_array` variable
templates instead of class templates.
This implements a warning that's similar to what GCC does in that
context: both memcpy and memset require their first and second operand
to be trivially copyable, let's warn if that's not the case.
Currently, the library-internal feature test macros are only defined if
the feature is not available, and always have the prefix
`_LIBCPP_HAS_NO_`. This patch changes that, so that they are always
defined and have the prefix `_LIBCPP_HAS_` instead. This changes the
canonical use of these macros to `#if _LIBCPP_HAS_FEATURE`, which means
that using an undefined macro (e.g. due to a missing include) is
diagnosed now. While this is rather unlikely currently, a similar change
in `<__configuration/availability.h>` caught a few bugs. This also
improves readability, since it removes the double-negation of `#ifndef
_LIBCPP_HAS_NO_FEATURE`.
The current patch only touches the macros defined in `<__config>`. If
people are happy with this approach, I'll make a follow-up PR to also
change the macros defined in `<__config_site>`.
It turns out that we can never do bounds-checking for unique_ptrs with
custom deleters, except when converting from a unique_ptr with a default
deleter to one with a custom deleter.
If we had an API like `std::make_unique` that allowed passing a custom
deleter, we could at least get bounds checking when the unique_ptr is
created through those APIs, but for now that is not possible.
Fixes#110683
