I just ran into a compiler error involving __bind_back and some overloads
that were being disabled with _EnableIf. I noticed that the error message
was quite bad and did not mention the reason for the overload being
excluded. Specifically, the error looked like this:
candidate template ignored: substitution failure [with _Args =
<ContiguousView>]: no member named '_EnableIfImpl' in 'std::_MetaBase<false>'
Instead, when using enable_if or enable_if_t, the compiler is clever and
can produce better diagnostics, like so:
candidate template ignored: requirement 'is_invocable_v<
std::__bind_back_op<1, std::integer_sequence<unsigned long, 0>>,
std::ranges::views::__transform::__fn &, std::tuple<PlusOne> &,
ContiguousView>' was not satisfied [with _Args = <ContiguousView>]
Basically, it tries to do a poor man's implementation of concepts, which
is already a lot better than simply complaining about substitution failure.
Hence, this commit uses enable_if_t instead of _EnableIf whenever
possible. That is both more straightforward than using the internal
helper, and also leads to better error messages in those cases.
I understand the motivation for _EnableIf's implementation was to improve
compile-time performance, however I believe striving to improve error
messages is even more important for our QOI, hence this patch. Furthermore,
it is unclear that _EnableIf actually improved compile-time performance
in any noticeable way (see discussion in the review for details).
Differential Revision: https://reviews.llvm.org/D108216
All supported compilers have supported deduction guides in C++17 for a
while, so this isn't necessary anymore.
Differential Revision: https://reviews.llvm.org/D108213
This affects only vectors with weird/malicious allocators,
the same corner case covered in D91708, but for `vector<bool>` this time.
Also ADL-proof <__tree>, which affects only sets and maps with weird/malicious
allocators where the ADL trap is in the *fancy pointer type*.
Also drive-by _VSTD:: qualification in the guts of std::bind,
std::packaged_task, std::condition_variable.
Differential Revision: https://reviews.llvm.org/D93424
I used a lot of `git grep` to find places where `std::` was being used
outside of comments and assert-messages. There were three outcomes:
- Qualified function calls, e.g. `std::move` becomes `_VSTD::move`.
This is the most common case.
- Typenames that don't need qualification, e.g. `std::allocator` becomes `allocator`.
Leaving these as `_VSTD::allocator` would also be fine, but I decided
that removing the qualification is more consistent with existing practice.
- Names that specifically need un-versioned `std::` qualification,
or that I wasn't sure about. For example, I didn't touch any code in
<atomic>, <math.h>, <new>, or any ext/ or experimental/ headers;
and I didn't touch any instances of `std::type_info`.
In some deduction guides, we were accidentally using `class Alloc = typename std::allocator<T>`,
despite `std::allocator<T>`'s type-ness not being template-dependent.
Because `std::allocator` is a qualified name, this did parse as we intended;
but what we meant was simply `class Alloc = allocator<T>`.
Differential Revision: https://reviews.llvm.org/D92250
We don't support any compiler that doesn't support variadics and rvalue
references in C++03 mode, so these workarounds can be dropped. There's
still *a lot* of cruft related to these workarounds, but I try to tackle
a bit of it here and there.
Like we do for empty std::array, make sure we have assertions in place
for obvious out-of-bounds issues in std::array when the debug mode is
enabled (which isn't by default).
The Standard is currently unimplementable. We have to pick between:
1. Not implementing constexpr support properly in std::array<T, 0>
2. Making std::array<T, 0> non-trivial even when T is trivial
3. Returning nullptr from std::array<T, 0>::begin()
Libc++ initially picked (1). In 77b9abfc8e, we started implementing constexpr properly, but lost the guarantee of triviality. Since it seems like both (1) and (2) are really important, it seems like (3) is the only viable option for libc++, after all. This is also what other implementations are doing.
This patch moves libc++ from (1) to (3).
It also:
- Improves the test coverage for the various ways of initializing std::array
- Adds tests for the triviality of std::array
- Adds tests for the aggregate-ness of std::array
Reviewed By: #libc, miscco, EricWF, zoecarver
Differential Revision: https://reviews.llvm.org/D80821
This commit adds missing support for constexpr in std::array under all
standard modes up to and including C++20. It also transforms the <array>
tests to check for constexpr-friendliness under the right standard modes.
Fixes https://llvm.org/PR40124
Fixes rdar://57522096
Supersedes https://reviews.llvm.org/D60666
Differential Revision: https://reviews.llvm.org/D80452
The use of the `&& ...` fold expression in std::array's deduction guides
recursively builds a set of binary operator expressions of depth N where
`N` is the number of elements in the initializer.
This is problematic because arrays may be large, and instantiation
depth is limited.
This patch addresses the issue by flattening the SFINAE using
the existing `__all` type trait.
Summary:
This patch implements https://wg21.link/P0325.
Please mind that at it is my first contribution to libc++, so I may have forgotten to abide to some conventions.
Reviewers: EricWF, mclow.lists, ldionne, lichray
Reviewed By: ldionne, lichray
Subscribers: lichray, dexonsmith, zoecarver, christof, ldionne, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D69882
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
An array T[1] isn't necessarily the same say when it's
a member of a struct. This patch addresses that problem and corrects
the tests to deal with it.
llvm-svn: 324545
Summary:
This patch fixes llvm.org/PR35491 and LWG2157 (https://cplusplus.github.io/LWG/issue2157)
The fix attempts to maintain ABI compatibility by replacing the array with a instance of `aligned_storage`.
Reviewers: mclow.lists, EricWF
Reviewed By: EricWF
Subscribers: lichray, cfe-commits
Differential Revision: https://reviews.llvm.org/D41223
llvm-svn: 324526
Revert "Fix initialization of array<const T, 0> with GCC."
Revert "Make array<const T, 0> non-CopyAssignable and make swap and fill ill-formed."
This reverts commit r324182, r324185, and r324194 which were causing issues with zero-length std::arrays.
llvm-svn: 324309
Previously, when handling zero-sized array of const objects we
used a const version of aligned_storage_t, which is not an array type.
However, GCC complains about initialization of the form: array<const T, 0> arr = {};
This patch fixes that bug by making the dummy object used to represent
the zero-sized array an array itself. This avoids GCC's complaints
about the uninitialized const member.
llvm-svn: 324194
The standard isn't exactly clear how std::array should handle zero-sized arrays
with const element types. In particular W.R.T. copy assignment, swap, and fill.
This patch takes the position that those operations should be ill-formed,
and makes changes to libc++ to make it so.
This follows up on commit r324182.
llvm-svn: 324185
Summary:
This patch fixes llvm.org/PR35491 and LWG2157 (https://cplusplus.github.io/LWG/issue2157)
The fix attempts to maintain ABI compatibility by replacing the array with a instance of `aligned_storage`.
Reviewers: mclow.lists, EricWF
Reviewed By: EricWF
Subscribers: lichray, cfe-commits
Differential Revision: https://reviews.llvm.org/D41223
llvm-svn: 324182
Summary:
This patch improves how libc++ handles min/max macros within the headers. Previously libc++ would undef them and emit a warning.
This patch changes libc++ to use `#pragma push_macro` to save the macro before undefining it, and `#pragma pop_macro` to restore the macros and the end of the header.
Reviewers: mclow.lists, bcraig, compnerd, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits, krytarowski
Differential Revision: https://reviews.llvm.org/D33080
llvm-svn: 304357
The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).
This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.
llvm-svn: 291035
Summary:
There is no reason to guard `tuple_size`, `tuple_element` and `get<I>(...)` for pair and array inside of `<__tuple>` so that they are only available when we have variadic templates.
This requires there be redundant declarations and definitions. It also makes it easy to get things wrong.
For example the following code should compile (and does in c++11).
```
#define _LIBCPP_HAS_NO_VARIADICS
#include <array>
int main()
{
static_assert((std::tuple_size<std::array<int, 10> volatile>::value == 10), "");
}
```
This patch lifts the non-variadic parts of `tuple_size`, `tuple_types`, and `get<I>(...)` to the top of `<__tuple>` where they don't require variadic templates. This patch also removes `<__tuple_03>` because there is no longer a need for it.
Reviewers: danalbert, K-ballo, mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D7774
llvm-svn: 232492
The patch touches these files:
locale
array
deque
new
string
utility
vector
__bit_reference
__split_buffer
locale_win32.h
There is no intended functionality change and it is expected that reversing the position of the inline keyword with regard to the other keywords does not change the meaning of anything, least not for apple/Linux etc.
It is intended to make libcxx more consistent with itself and to prevent the 1000 or so
"inline.cpp(3) : warning C4141: 'inline' : used more than once" warnings that MS's cl.exe compiler emits without this patch, i.e. if inline is not the first keyword before a function name etc.
Prefer "inline [other inline related keyword]" over "[other related keyword] inline".
After this patch, libcxx should be consistent to this pattern.
llvm-svn: 191987
Louis Dionne