Commit Graph

121 Commits

Author SHA1 Message Date
Nikolas Klauser 4887d047a3 [libc++][NFC] Replace enable_if with __enable_if_t in a few places
Reviewed By: ldionne, #libc

Spies: jloser, libcxx-commits

Differential Revision: https://reviews.llvm.org/D128400
2022-07-04 11:09:34 +02:00
Louis Dionne de4a57cb21 [libc++] Re-add transitive includes that had been removed since LLVM 14
This commit re-adds transitive includes that had been removed by
4cd04d1687, c36870c8e7, a83f4b9cda, 1458458b55, 2e2f3158c6,
and 489637e66d. This should cover almost all the includes that had
been removed since LLVM 14 and that would contribute to breaking user
code when releasing LLVM 15.

It is possible to disable the inclusion of these headers by defining
_LIBCPP_REMOVE_TRANSITIVE_INCLUDES. The intent is that vendors will
enable that macro and start fixing downstream issues immediately. We
can then remove the macro (and the transitive includes) by default in
a future release. That way, we will break users only once by removing
transitive includes in bulk instead of doing it bit by bit a every
release, which is more disruptive for users.

Note 1: The set of headers to re-add was found by re-generating the
        transitive include test on a checkout of release/14.x, which
        provided the list of all transitive includes we used to provide.

Note 2: Several includes of <vector>, <optional>, <array> and <unordered_map>
        have been added in this commit. These transitive inclusions were
        added when we implemented boyer_moore_searcher in <functional>.

Note 3: This is a best effort patch to try and resolve downstream breakage
        caused since branching LLVM 14. I wasn't able to perfectly mirror
        transitive includes in LLVM 14 for a few headers, so I added a
        release note explaining it. To summarize, adding boyer_moore_searcher
        created a bunch of circular dependencies, so we have to break
        backwards compatibility in a few cases.

Differential Revision: https://reviews.llvm.org/D128661
2022-06-27 22:18:19 -04:00
Nikolas Klauser db1978b674 [libc++] Mark standard-mandated includes as such
Reviewed By: ldionne, Mordante, #libc, saugustine

Spies: saugustine, MaskRay, arichardson, mstorsjo, jloser, libcxx-commits, arphaman

Differential Revision: https://reviews.llvm.org/D127953
2022-06-17 20:43:33 +02:00
Mark de Wever 4cd04d1687 [libc++] Removes unneeded <iterator> includes.
Reviewed By: #libc, philnik

Differential Revision: https://reviews.llvm.org/D127675
2022-06-15 18:14:05 +02:00
Nikolas Klauser 3cd4531b9b [libc++] Granularize <iterator> includes
Reviewed By: ldionne, #libc

Spies: libcxx-commits, wenlei

Differential Revision: https://reviews.llvm.org/D127445
2022-06-10 22:43:57 +02:00
Louis Dionne f3966eaf86 [libc++] Make the Debug mode a configuration-time only option
The debug mode has been broken pretty much ever since it was shipped
because it was possible to enable the debug mode in user code without
actually enabling it in the dylib, leading to ODR violations that
caused various kinds of failures.

This commit makes the debug mode a knob that is configured when
building the library and which can't be changed afterwards. This is
less flexible for users, however it will actually work as intended
and it will allow us, in the future, to add various kinds of checks
that do not assume the same ABI as the normal library. Furthermore,
this will make the debug mode more robust, which means that vendors
might be more tempted to support it properly, which hasn't been the
case with the current debug mode.

This patch shouldn't break any user code, except folks who are building
against a library that doesn't have the debug mode enabled and who try
to enable the debug mode in their code. Such users will get a compile-time
error explaining that this configuration isn't supported anymore.

In the future, we should further increase the granularity of the debug
mode checks so that we can cherry-pick which checks to enable, like we
do for unspecified behavior randomization.

Differential Revision: https://reviews.llvm.org/D122941
2022-06-07 16:33:53 -04:00
Louis Dionne 4eab04f849 [libc++] Remove a bunch of conditionals on _LIBCPP_DEBUG_LEVEL
Instead of providing two different constructors for iterators that
support the debug mode, provide a single constructor but leave the
container parameter unused when the debug mode is not enabled.

This allows simplifying all the call sites to unconditionally pass
the container, which removes a bunch of duplication in the container's
implementation.

Note that this patch does add some complexity to std::span, however
that is only because std::span has the ability to use raw pointers
as iterators instead of __wrap_iter. In retrospect, I believe it was
a mistake to provide that capability, and so it will be removed in a
future patch, along with the complexity added by this patch.

Differential Revision: https://reviews.llvm.org/D126993
2022-06-06 09:54:26 -04:00
Nikolas Klauser c095440caf [libc++] Remove __invalidate_all_iterators and replace the uses with std::__debug_db_invalidate_all
Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D125188
2022-05-11 21:36:06 +02:00
Nikolas Klauser 08f68dfef6 [libc++] Add a few more debug wrapper functions
Reviewed By: ldionne, #libc, jloser

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D125176
2022-05-11 21:32:37 +02:00
Mark de Wever 889302292b [libc++][format][3/6] Adds a __container_buffer.
Instead of writing every character directly into the container by using
a `back_insert_iterator` the data is buffered in an `array`. This buffer
is then inserted to the container by calling its `insert` member function.

Since there's no guarantee every container's `insert` behaves properly
containers need to opt-in to this behaviour. The appropriate standard
containers opt-in to this behaviour.

This change improves the performance of the format functions that use a
`back_insert_iterator`.

Depends on D110495

Reviewed By: ldionne, vitaut, #libc

Differential Revision: https://reviews.llvm.org/D110497
2022-04-09 09:35:48 +02:00
Louis Dionne 385cc25a53 [libc++] Ensure that all public C++ headers include <__assert>
This patch changes the requirement for getting the declaration of the
assertion handler from including <__assert> to including any public
C++ header of the library. Note that C compatibility headers are
excluded because we don't implement all the C headers ourselves --
some of them are taken straight from the C library, like assert.h.

It also adds a generated test to check it. Furthermore, this new
generated test is designed in a way that will make it possible to
replace almost all the existing test-generation scripts with this
system in upcoming patches.

Differential Revision: https://reviews.llvm.org/D122506
2022-03-30 15:05:31 -04:00
Nikolas Klauser 3c6bd176fb [libc++] Rename __identity to __type_identity
In C++20 the type trait `type_identity` was introduced. For the same purpose there is `__identity` for pre-C++20 code. The name is confusing, because since C++20 there is also `identity`, which isn't a type trait.

Reviewed By: ldionne, Mordante, #libc

Spies: EricWF, libcxx-commits

Differential Revision: https://reviews.llvm.org/D122017
2022-03-25 01:01:28 +01:00
Louis Dionne c87c8917e3 [libc++] Audit all uses of _LIBCPP_ASSERT and _LIBCPP_DEBUG_ASSERT
I audited all uses of _LIBCPP_ASSERT to make sure that we only used it
for "basic assertions", i.e. assertions with constant-time conditions.
I also audited all uses of _LIBCPP_DEBUG_ASSERT to make sure we used it
only for debug-mode assertions, and in one case had to change for
_LIBCPP_ASSERT instead.

As a fly-by, I also changed a couple of tests against nullptr or 0 to
be more explicit.

After this patch, all uses of _LIBCPP_ASSERT should be with constant-time
conditions, and all uses of _LIBCPP_DEBUG_ASSERT should be with conditions
that we only want to check when the debug mode is enabled.

Differential Revision: https://reviews.llvm.org/D122395
2022-03-24 13:13:21 -04:00
Nikolas Klauser 52915d78f4 [libc++] Granularize <utility> includes
Reviewed By: ldionne, #libc

Spies: EricWF, libcxx-commits, arphaman

Differential Revision: https://reviews.llvm.org/D120466
2022-03-05 19:31:46 +01:00
Louis Dionne f87aa19be6 [libc++] Move everything related solely to _LIBCPP_ASSERT to its own file
This is the first step towards disentangling the debug mode and assertions
in libc++. This patch doesn't make any functional change: it simply moves
_LIBCPP_ASSERT-related stuff to its own file so as to make it clear that
libc++ assertions and the debug mode are different things. Future patches
will make it possible to enable assertions without enabling the debug
mode.

Differential Revision: https://reviews.llvm.org/D119769
2022-02-16 12:49:50 -05:00
Nikolas Klauser 2e2f3158c6 [libc++] Granularize algorithm includes
Reviewed By: Mordante, ldionne, Quuxplusone, #libc, #libc_abi

Spies: #libc_vendors, libcxx-commits, miyuki

Differential Revision: https://reviews.llvm.org/D119667
2022-02-16 04:12:22 +01:00
Arthur O'Dwyer fa6b9e4010 [libc++] Normalize all our '#pragma GCC system_header', and regression-test.
Now we'll notice if a header forgets to include this magic phrase.

Differential Revision: https://reviews.llvm.org/D118800
2022-02-04 12:27:19 -05:00
Nikolas Klauser caf5548c7c [libc++] Introduce __debug_db_insert_i()
Introduce `__debug_db_insert_i()`

Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D117410
2022-01-17 20:31:21 +01:00
Nikolas Klauser e3cf70502c [libc++] Introduce __debug_db_insert_c()
There are a lot of
```
#if _LIBCPP_DEBUG_LEVEL == 2
    __get_db()->__insert_c(this);
#endif
```

This patch introduces `__debug_db_insert_c()` to put the `#if` in one central place.

Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D116947
2022-01-11 23:11:26 +01:00
Nikolas Klauser 2154dbaa59 [libc++][NFC] Use _LIBCPP_DEBUG_ASSERT in <list>
Use `_LIBCPP_DEBUG_ASSERT` in `<list>`

Reviewed By: Quuxplusone, ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D116938
2022-01-10 23:19:16 +01:00
Konstantin Varlamov 7da4ee6f23 [libcxx][NFC] Make sequence containers slightly more SFINAE-friendly during CTAD.
Disable the constructors taking `(size_type, const value_type&,
allocator_type)` if `allocator_type` is not a valid allocator.
Otherwise, these constructors are considered when resolving e.g.
`(int*, int*, NotAnAllocator())`, leading to a hard error during
instantiation. A hard error makes the Standard's requirement to not
consider deduction guides of the form `(Iterator, Iterator,
BadAllocator)` during overload resolution essentially non-functional.

The previous approach was to SFINAE away `allocator_traits`. This patch
SFINAEs away the specific constructors instead, for consistency with
`basic_string` -- see [LWG3076](wg21.link/lwg3076) which describes
a very similar problem for strings (note, however, that unlike LWG3076,
no valid constructor call is affected by the bad instantiation).

Differential Revision: https://reviews.llvm.org/D114311
2021-12-01 11:56:51 -08:00
Louis Dionne eb8650a757 [runtimes][NFC] Remove filenames at the top of the license notice
We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste stuff.
This cleans up all the existing files so as to stop the spreading
as people copy-paste headers around.
2021-11-17 16:30:52 -05:00
Mark de Wever 4732dd3010 [libc++] Use addressof in list.
This addresses the usage of `operator&` in `<list>`.

(Note there are still more headers with the same issue.)

Reviewed By: #libc, Quuxplusone, ldionne

Differential Revision: https://reviews.llvm.org/D112654
2021-11-11 18:56:08 +01:00
Konstantin Varlamov 68072a7166 [libc++] P0433R2: test that deduction guides are properly SFINAEd away.
Deduction guides for containers should not participate in overload
resolution when called with certain incorrect types (e.g. when called
with a template argument in place of an `InputIterator` that doesn't
qualify as an input iterator). Similarly, class template argument
deduction should not select `unique_ptr` constructors that take a
a pointer.

The tests try out every possible incorrect parameter (but never more
than one incorrect parameter in the same invocation).

Also add deduction guides to the synopsis for associative and unordered
containers (this was accidentally omitted from [D112510](https://reviews.llvm.org/D112510)).

Differential Revision: https://reviews.llvm.org/D112904
2021-11-09 09:32:24 -08:00
Mark de Wever 968e27397c [libc++] Use addressof to fix debug tests.
Fixes the tests added in D110852 for the debug iterators.

Similar issues with hijacking `operator&` still exist, they will be
addressed separately.

Reviewed By: #libc, ldionne, Quuxplusone

Differential Revision: https://reviews.llvm.org/D111564
2021-10-12 18:15:35 +02:00
Mark de Wever b8608b8723 [libc++] Use addressof in assignment operator.
Replace `&__rhs` with `_VSTD::addressof(__rhs)` to guard against ADL hijacking
of `operator&` in `operator=`. Thanks to @CaseyCarter for bringing it to our
attention.

Similar issues with hijacking `operator&` still exist, they will be
addressed separately.

Reviewed By: #libc, Quuxplusone, ldionne

Differential Revision: https://reviews.llvm.org/D110852
2021-10-07 18:10:47 +02:00
Arthur O'Dwyer 16bf43398a [libc++] Comma-operator-proof a lot of algorithm/container code.
Detected by evil-izing the widely used `MoveOnly` testing type.
I had to patch some tests that were themselves using its comma operator,
but I think that's a worthwhile cost in order to catch more places
in our headers that needed comma-proofing.

The trick here is that even `++ptr, SomeClass()` can find a comma operator
by ADL, if `ptr` is of type `Evil*`. (A comma between two operands
of non-class-or-enum type is always treated as the built-in
comma, without ADL. But if either operand is class-or-enum, then
ADL happens for _both_ operands' types.)

Differential Revision: https://reviews.llvm.org/D109414
2021-09-08 13:34:01 -04:00
Louis Dionne 4e0ea2cf2e [libc++] Use enable_if_t instead of _EnableIf
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
2021-09-08 09:09:28 -04:00
Louis Dionne 0166690401 [libc++] Remove workarounds for the lack of deduction guides in C++17
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
2021-08-18 08:57:25 -04:00
Christopher Di Bella 6adbc83ee9 [libcxx][modularisation] moves <utility> content out of <type_traits>
Moves:

* `std::move`, `std::forward`, `std::declval`, and `std::swap` into
  `__utility/${FUNCTION_NAME}`.
* `std::swap_ranges` and `std::iter_swap` into
  `__algorithm/${FUNCTION_NAME}`

Differential Revision: https://reviews.llvm.org/D103734
2021-06-24 17:57:29 +00:00
Arthur O'Dwyer dd15c2723c [libc++] [P1518R2] Better CTAD behavior for containers with allocators.
P1518 does the following in C++23 but we'll just do it in C++17 as well:
- Stop requiring `Alloc` to be an allocator on some container-adaptor deduction guides
- Stop deducing from `Allocator` on some sequence container constructors
- Stop deducing from `Allocator` on some other container constructors (libc++ already did this)

The affected constructors are the "allocator-extended" versions of
constructors where the non-allocator arguments are already sufficient
to deduce the allocator type. For example,

    std::pmr::vector<int> v1;
    std::vector v2(v1, std::pmr::new_delete_resource());
    std::stack s2(v1, std::pmr::new_delete_resource());

Differential Revision: https://reviews.llvm.org/D97742
2021-06-18 15:54:46 -04:00
Arthur O'Dwyer bfbd73f87d [libc++] Alphabetize and include-what-you-use. NFCI.
Differential Revision: https://reviews.llvm.org/D102781
2021-05-29 19:54:48 -04:00
Amy Huang 7c2f58278e Apply [[standalone_debug]] to some types in the STL.
Add this attribute to some types to ensure that they have
debug info.
The debug info for these classes are required for debuggers to display
some STL types. With constructor homing (a new debug info optimization)
their debug info isn't emitted because their constructors are never
called.

The list of types with the attribute added are __hash_value_type,
__value_type, __tree_node_base, __tree_node, __hash_node, __list_node,
and __forward_list_node.

Differential Revision: https://reviews.llvm.org/D98750
2021-05-18 17:01:07 -07:00
Kristina Bessonova a18b5f0188 [libcxx] NFC. Add missed articles to _LIPCPP_ASSERT messages in <list> 2021-05-17 10:15:43 +02:00
Kristina Bessonova 96100f1508 [libcxx] NFC. Correct wordings of _LIBCPP_ASSERT debug messages
Differential Revision: https://reviews.llvm.org/D102195
2021-05-12 13:49:57 +02:00
Louis Dionne 4cd6ca102a [libc++] NFC: Normalize `#endif //` comment indentation 2021-04-20 12:03:32 -04:00
Arthur O'Dwyer 5e7367d3e4 Add a missing debug assertion in <list>.
This came up in D100595.

Differential Revision: https://reviews.llvm.org/D100728
2021-04-18 19:40:17 -04:00
Arthur O'Dwyer 199d2ebeed [libc++] Use _EnableIf and __iter_value_type consistently. NFCI.
Specifically, use these metafunctions consistently in areas that are
about to be affected by P1518R2's changes.

This is the NFCI part of https://reviews.llvm.org/D97742 .
The functional-change part is still waiting for P1518R2 to be
officially merged into the working draft.
2021-03-29 09:22:52 -04:00
Arthur O'Dwyer b6f1917415 [libc++] Fix some one-off typos in comments. NFCI. 2020-12-14 09:54:58 -05:00
Arthur O'Dwyer 3696227c10 [libc++] ADL-proof by adding _VSTD:: qualifications to memmove etc.
Generally these calls aren't vulnerable to ADL because they involve only
primitive types. The ones in <list> and <vector> drag in namespace std
but that's OK; the ones in <fstream> and <strstream> are vulnerable
iff `CharT` is an enum type, which seems far-fetched.
But absolutely zero of them *need* ADL to happen; so in my opinion
they should all be consistently qualified, just like calls to any
other (non-user-customizable) functions in namespace std.

Also: Include <cstring> and <cwchar> in <__string>.
We seemed to be getting lucky that <memory> included <iterator>
included <iosfwd> included <wchar.h>. That gave us the
global-namespace `wmemmove`, but not `_VSTD::wmemmove`.
This is now fixed.

I didn't touch these headers:
<ext/__hash> uses strlen, safely
<support/ibm/locale_mgmt_aix.h> uses memcpy, safely
<string.h> uses memchr and strchr, safely
<wchar.h> uses wcschr, safely
<__bsd_locale_fallbacks.h> uses wcsnrtombs, safely

Differential Revision: https://reviews.llvm.org/D93061
2020-12-10 22:03:12 -05:00
Arthur O'Dwyer d586f92c94 [libc++] Consistently replace `std::` qualification with `_VSTD::` or nothing. NFCI.
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
2020-12-01 22:13:39 -05:00
Arthur O'Dwyer 6e965df605 Revert "Revert "[libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls.""
This reverts commit 620adacf87.

Fix: unsupport C++03 for the new test, define helpers before __swap_allocator

(1) Add _VSTD:: qualification to __swap_allocator.

(2) Add _VSTD:: qualification consistently to __to_address.

(3) Add some more missing _VSTD:: to <vector>, with a regression test.
This part is cleanup after d9a4f936d0.

Note that a vector whose allocator actually runs afoul of any of these ADL calls will
likely also run afoul of simple things like `v1 == v2` (which is also an ADL call).
But, still, libc++ should be consistent in qualifying function calls wherever possible.

Relevant blog post: https://quuxplusone.github.io/blog/2019/09/26/uglification-doesnt-stop-adl/

Differential Revision: https://reviews.llvm.org/D91708
2020-11-20 20:59:18 -05:00
Mikhail Goncharov 620adacf87 Revert "[libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls."
This reverts commit 40267cc989.

Build fails, e.g. http://lab.llvm.org:8011/#/builders/23/builds/108
2020-11-19 15:36:49 +01:00
Arthur O'Dwyer 40267cc989 [libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls.
(1) Add _VSTD:: qualification to __swap_allocator.

(2) Add _VSTD:: qualification consistently to __to_address.

(3) Add some more missing _VSTD:: to <vector>, with a regression test.
This part is cleanup after d9a4f936d0.

Note that a vector whose allocator actually runs afoul of any of these ADL calls will
likely also run afoul of simple things like `v1 == v2` (which is also an ADL call).
But, still, libc++ should be consistent in qualifying function calls wherever possible.

Relevant blog post: https://quuxplusone.github.io/blog/2019/09/26/uglification-doesnt-stop-adl/

Differential Revision: https://reviews.llvm.org/D91708
2020-11-19 09:19:16 -05:00
Louis Dionne 31e820378b [libc++] NFCI: Simplify macro definitions for the debug mode
The debug mode always had three possibilities:
- _LIBCPP_DEBUG is undefined => no assertions
- _LIBCPP_DEBUG == 0         => some assertions
- _LIBCPP_DEBUG == 1         => some assertions + iterator checks

This was documented that way, however the code did not make this clear
at all. The discrepancy between _LIBCPP_DEBUG and _LIBCPP_DEBUG_LEVEL
was especially confusing. I reworked how the various macros are defined
without changing anything else to make the code clearer.
2020-10-02 15:11:23 -04:00
Marek Kurdej 3e895085de [libc++][P1115][C++20] Improving the Return Value of Erase-Like Algorithms II: Free erase/erase if.
Summary:
This patch adds return type to std::erase and std::erase_if functions.

Also:
* Update __cpp_lib_erase_if to 202002L.
* Fix synopsis in unordered_map.
* Fix generate_feature_test_macro_components.py script.

Reviewers: EricWF, mclow.lists, ldionne, #libc

Reviewed By: ldionne, #libc

Subscribers: broadwaylamb, zoecarver, dexonsmith, ldionne, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D75905
2020-05-02 14:04:50 +02:00
Eric Fiselier 549545b64a [libc++] Rework compressed pair constructors.
This patch de-duplicates most compressed pair constructors
to use the same code in C++11 and C++03.

Part of doing that is deleting the "__second_tag()" and replacing
it with a "__value_init_tag()" which has the same effect, but
allows for the removal of the special "one-arg" first element
constructor.

This patch is intended to have no semantic change.
2019-12-16 18:38:58 -05:00
Eric Fiselier f82dba0192 Rename __is_foo_iterator traits to reflect their Cpp17 nature.
With the upcoming introduction of iterator concepts in ranges,
the meaning of "__is_contiguous_iterator" changes drastically.

Currently we intend it to mean "does it have this iterator category",
but it could now also mean "does it meet the requirements of this
concept", and these can be different.
2019-11-18 01:49:32 -05:00
Louis Dionne 6b77ebdc91 [NFC] Strip trailing whitespace from libc++ 2019-10-23 11:19:19 -07:00
Marshall Clow f814dcbafb Make forward_list::remove/remove_if/unique all return void before C++20; undoes that bit of D58332. Thanks to Mikhail Maltsev for pointing this out
llvm-svn: 365290
2019-07-08 03:45:28 +00:00