49 Commits

Author SHA1 Message Date
Nikolas Klauser
af9c04fa68
[libc++] Remove _LIBCPP_TEMPLATE_VIS (#134885)
The need for `_LIBCPP_TEMPLATE_VIS` has been removed in #133233.
2025-04-09 23:47:57 +02:00
Nikolas Klauser
c13c04fdfe
[libc++] Simplify the implementation of the pointer aliases in allocator_traits (#127079) 2025-03-28 10:27:00 +01:00
Nikolas Klauser
a8e168e0c1
[libc++][NFC] Replace structs with variable templates in <__memory/allocator_traits.h> (#129237)
Variable templates are a bit easier on the compiler and improve the
readability of the code.
2025-03-25 15:58:24 +01:00
Mark de Wever
9feac2cbd0 [libc++] Improve deprecated diagnostic guards.
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.
2025-03-18 18:30:48 +01:00
Mark de Wever
fd973d2512
[libc++] Protect more code against -Wdeprecated. (#130419)
This seems needed when updating the CI Docker image.
2025-03-09 17:33:59 +01:00
cmtice
384e69a914
[libc++] Add _LIBCPP_NODEBUG on internal allocator trait aliases (#118835)
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.
2024-12-06 08:53:56 -05:00
Nikolas Klauser
7ae61a36f9
[libc++] Add __detected_or_t and use it to implement some of the allocator traits aliases (#115654)
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.
2024-11-26 23:53:26 +01:00
Nikolas Klauser
e99c4906e4
[libc++] Granularize <cstddef> includes (#108696) 2024-10-31 02:20:10 +01:00
Louis Dionne
09e3a36058
[libc++][modules] Fix missing and incorrect includes (#108850)
This patch adds a large number of missing includes in the libc++ headers
and the test suite. Those were found as part of the effort to move
towards a mostly monolithic top-level std module.
2024-09-16 15:06:20 -04:00
Nikolas Klauser
17e0686ab1
[libc++][NFC] Use [[__nodiscard__]] unconditionally (#80454)
`__has_cpp_attribute(__nodiscard__)` is always true now, so we might as
well replace `_LIBCPP_NODISCARD`. It's one less macro that can result in
bad diagnostics.
2024-09-12 21:18:43 +02:00
Hristo Hristov
e475bb7ac3
[libc++][memory] P1132R8: out_ptr - a scalable output pointer abstraction (#73618)
Differential Revision: https://reviews.llvm.org/D150525

Implements:
- https://wg21.link/P1132R8 - `out_ptr` - a scalable output pointer
abstraction
- https://eel.is/c++draft/smartptr.adapt - 20.3.4 Smart pointer adaptors
- https://wg21.link/LWG3734 - Inconsistency in `inout_ptr` and `out_ptr`
for empty case
- https://wg21.link/LWG3897- `inout_ptr` will not update raw pointer to
0

---------

Co-authored-by: Hristo Hristov <zingam@outlook.com>
2024-07-19 06:38:02 +03:00
Hui
79e8a59523
[libc++] Move allocator assertion into allocator_traits (#94750)
There is code duplication in all containers that static_assert the
allocator matches the allocator requirements in the spec. This check can
be moved into a more centralised place.
2024-06-25 10:13:48 -05:00
Nikolas Klauser
83bc7b5771
[libc++] Remove _LIBCPP_DISABLE_NODISCARD_EXTENSIONS and refactor the tests (#87094)
This also adds a few tests that were missing.
2024-04-22 22:13:58 +02:00
Nikolas Klauser
61f1f13002
[libc++][NFC] Move basic ASan annotation functions into a utility header (#87220) 2024-04-13 18:24:12 +02:00
Nikolas Klauser
580f60484e
[libc++][NFC] Merge is{,_nothrow,_trivially}{,_copy,_move,_default}{_assignable,_constructible} (#85308)
These headers have become very small by using compiler builtins, often
containing only two declarations. This merges these headers, since
there doesn't seem to be much of a benefit keeping them separate.

Specifically, `is_{,_nothrow,_trivially}{assignable,constructible}` are
kept and the `copy`, `move` and `default` versions of these type traits
are moved in to the respective headers.
2024-03-18 08:29:44 +01:00
Nikolas Klauser
76a2472715
[libc++] Refactor more __enable_ifs to the canonical style (#81457)
This brings the code base closer to having only a single style of
`enable_if`s.
2024-02-20 01:47:38 +01:00
Hristo Hristov
7d78ccf7d5
[libc++][memory] P2652R2: Disallow Specialization of allocator_traits (#79978)
Implements P2652R2 <https://wg21.link/P2652R2>:
- https://eel.is/c++draft/allocator.requirements.general
- https://eel.is/c++draft/memory.syn
- https://eel.is/c++draft/allocator.traits.general
- https://eel.is/c++draft/allocator.traits.members
- https://eel.is/c++draft/diff.cpp20.concepts
- https://eel.is/c++draft/diff.cpp20.utilities

---------

Co-authored-by: Zingam <zingam@outlook.com>
2024-02-01 12:31:25 +01:00
Louis Dionne
9783f28cbb
[libc++] Format the code base (#74334)
This patch runs clang-format on all of libcxx/include and libcxx/src, in
accordance with the RFC discussed at [1]. Follow-up patches will format
the benchmarks, the test suite and remaining parts of the code. I'm
splitting this one into its own patch so the diff is a bit easier to
review.

This patch was generated with:

   find libcxx/include libcxx/src -type f \
      | grep -v 'module.modulemap.in' \
      | grep -v 'CMakeLists.txt' \
      | grep -v 'README.txt' \
      | grep -v 'libcxx.imp' \
      | grep -v '__config_site.in' \
      | xargs clang-format -i

A Git merge driver is available in libcxx/utils/clang-format-merge-driver.sh
to help resolve merge and rebase issues across these formatting changes.

[1]: https://discourse.llvm.org/t/rfc-clang-formatting-all-of-libc-once-and-for-all
2023-12-18 14:01:33 -05:00
Louis Dionne
77a00c0d54
[libc++] Replace uses of _VSTD:: by std:: (#74331)
As part of the upcoming clang-formatting of libc++, this patch performs
the long desired removal of the _VSTD macro.

See https://discourse.llvm.org/t/rfc-clang-formatting-all-of-libc-once-and-for-all
for the clang-format proposal.
2023-12-05 11:19:15 -05:00
Louis Dionne
4c19854222
[libc++] Rename _LIBCPP_INLINE_VISIBILITY to _LIBCPP_HIDE_FROM_ABI (#74095)
In preparation for running clang-format on the whole code base, we are
also removing mentions of the legacy _LIBCPP_INLINE_VISIBILITY macro in
favor of the newer _LIBCPP_HIDE_FROM_ABI.

We're still leaving the definition of _LIBCPP_INLINE_VISIBILITY to avoid
creating needless breakage in case some older patches are checked-in
with mentions of the old macro. After we branch for LLVM 18, we can do
another pass to clean up remaining uses of the macro that might have
gotten introduced by mistake (if any) and remove the macro itself at the
same time. This is just a minor convenience to smooth out the transition
as much as possible.

See
https://discourse.llvm.org/t/rfc-clang-formatting-all-of-libc-once-and-for-all
for the clang-format proposal.
2023-12-04 10:25:14 -05:00
philnik777
cd9829c231
[libc++][NFC] Use __construct_at and __destroy_at instead of using preprocessor conditionals (#70866) 2023-11-26 20:47:03 +01:00
Tacet
8a454e1e3c
[libc++][ASan] Removing clang version checks (#71673)
This commit removes checks like `_LIBCPP_CLANG_VER >= 1600` related to
ASan annotations. As only 2 previous versions are supported, it's a TODO
for LLVM 18.
2023-11-08 16:28:08 -10:00
Mark de Wever
4ef1393e1b [libc++][doc] Updates the tasks to do for a release.
This is a followup of the review comments in D144499.

Reviewed By: ldionne, philnik, #libc

Differential Revision: https://reviews.llvm.org/D150585
2023-05-23 19:02:17 +02:00
Advenam Tacet
2fa1bec7a2 [ASan][libcxx] A way to turn off annotations for containers with a specific allocator
This revision is part of our efforts to support container annotations with (almost) every allocator.
That patch is necessary to enable support for most annotations (D136765). Without a way to turn off annotations, it's hard to use ASan with area allocators (no calls to destructors).

This is an answer to a request about it. This patch provides a solution to the aforementioned issue by introducing a new template structure `__asan_annotate_container_with_allocator`, which allows the disabling of container annotations for a specific allocator.

This patch also introduces `_LIBCPP_HAS_ASAN_CONTAINER_ANNOTATIONS_FOR_ALL_ALLOCATORS` FTM.

To turn off annotations, it is sufficient to create a template specialization with a false value using a [Unary Type Trait](https://en.cppreference.com/w/cpp/types/integral_constant).

The proposed structure is being used in the code enabling annotations for all allocators in `std::vector`, `std::basic_string`, and `std::deque`. (D136765 D146214 D146815)

Possibility to do it was added to ASan API in rGdd1b7b797a116eed588fd752fbe61d34deeb24e4 commit.

For context on not calling a destructor, look at https://eel.is/c++draft/basic.life#5 and notes there, you may also read a discussion in D136765.

Reviewed By: ldionne, philnik, #libc, hans

Spies: EricWF, mikhail.ramalho, #sanitizers, libcxx-commits, hans, vitalybuka

Differential Revision: https://reviews.llvm.org/D145628
2023-05-04 14:17:25 -07:00
Nikolas Klauser
4f15267d3d [libc++][NFC] Replace _LIBCPP_STD_VER > x with _LIBCPP_STD_VER >= x
This change is almost fully mechanical. The only interesting change is in `generate_feature_test_macro_components.py` to generate `_LIBCPP_STD_VER >=` instead. To avoid churn in the git-blame this commit should be added to the `.git-blame-ignore-revs` once committed.

Reviewed By: ldionne, var-const, #libc

Spies: jloser, libcxx-commits, arichardson, arphaman, wenlei

Differential Revision: https://reviews.llvm.org/D143962
2023-02-15 16:52:25 +01:00
Nikolas Klauser
73e8e1ba8d [libc++][NFC] Qualify declval
While it's not necessary to qualify calls to `declval` it makes error messages very crypric if the declaration isn't reachable anymore

For example:
```
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:53:66: error: no type named 'type' in 'std::common_type<long, long>'
        typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:107:14: note: in instantiation of template class 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>, std::chrono::duration<long, std::ratio<3600, 1>>>' requested here
        : public common_type<_Tp, _Tp> {};
                 ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:279:58: note: in instantiation of template class 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>>' requested here
        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
                                                             ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:308:54: note: in instantiation of template class 'std::chrono::duration<long, std::ratio<3600, 1>>' requested here
    typedef duration<     int, ratio_multiply<ratio<24>, hours::period>>         days;
                                                         ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:280:81: error: no type named 'type' in 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>>'
        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
                                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:308:54: note: in instantiation of template class 'std::chrono::duration<long, std::ratio<3600, 1>>' requested here
    typedef duration<     int, ratio_multiply<ratio<24>, hours::period>>         days;
                                                         ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:53:66: error: no type named 'type' in 'std::common_type<int, int>'
        typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:107:14: note: in instantiation of template class 'std::common_type<std::chrono::duration<int, std::ratio<86400, 1>>, std::chrono::duration<int, std::ratio<86400, 1>>>' requested here
        : public common_type<_Tp, _Tp> {};
                 ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:279:58: note: in instantiation of template class 'std::common_type<std::chrono::duration<int, std::ratio<86400, 1>>>' requested here
        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
                                                             ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:309:55: note: in instantiation of template class 'std::chrono::duration<int, std::ratio<86400, 1>>' requested here
    typedef duration<     int, ratio_multiply<ratio<7>,   days::period>>         weeks;
                                                          ^
    19 similar errors omitted
```
changes with qualification added to:
```
    While building module 'std' imported from /home/nikolask/llvm-projects/libcxx/libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_type.pass.cpp:13:
    In file included from <module-includes>:17:
    In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/math.h:309:
    In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/limits:107:
    In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/type_traits:432:
    In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_reference.h:13:
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:28:43: error: declaration of 'declval' must be imported from module 'std.utility.__utility.declval' before it is required
    using __cond_type = decltype(false ? std::declval<_Tp>() : std::declval<_Up>());
                                              ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__utility/declval.h:30:34: note: declaration here is not visible
    decltype(std::__declval<_Tp>(0)) declval() _NOEXCEPT;
                                     ^
    /home/nikolask/llvm-projects/libcxx/libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_type.pass.cpp:13:10: fatal error: could not build module 'std'
    #include <functional>
     ~~~~~~~~^
    2 errors generated.
```

Reviewed By: ldionne, Mordante, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D130854
2023-01-12 18:28:41 +01:00
Nikolas Klauser
e0a66116fc [libc++] Granularize <type_traits> includes in <compare>
Reviewed By: Mordante, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D140480
2022-12-23 02:58:06 +01:00
Nikolas Klauser
8e892c9dd8 [libc++] Improve error message for invalid allocators
Reviewed By: ldionne, #libc

Spies: libcxx-commits, rupprecht

Differential Revision: https://reviews.llvm.org/D135803
2022-10-16 00:37:35 +02:00
Nikolas Klauser
d7d586e5a7 [libc++] static_assert that rebinding the allocator works as expected
Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D133638
2022-10-11 16:47:42 +02:00
Nikolas Klauser
ed2d3644ab [libc++][NFC] Prefer type aliases over structs
Reviewed By: ldionne, #libc

Spies: sstefan1, libcxx-commits, jeroen.dobbelaere

Differential Revision: https://reviews.llvm.org/D134901
2022-10-01 22:49:36 +02:00
Nikolas Klauser
5fab33af7f [libc++] Avoid instantiating type_trait classes
Use `using` aliases to avoid instantiating lots of types

Reviewed By: ldionne, #libc

Spies: libcxx-commits, miyuki

Differential Revision: https://reviews.llvm.org/D132785
2022-09-06 19:09:42 +02:00
Nikolas Klauser
5146b57b40 [libc++][NFC] Rename the constexpr macros
This was discussed on Discord with the consensus that we should rename the macros.

Reviewed By: ldionne, Mordante, var-const, avogelsgesang, jloser, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D131498
2022-08-19 15:35:02 +02:00
Louis Dionne
368faacac7 [libc++] Revert "Protect users from relying on detail headers" & related changes
This commit reverts 5aaefa51 (and also partly 7f285f48e77 and b6d75682f9,
which were related to the original commit). As landed, 5aaefa51 had
unintended consequences on some downstream bots and didn't have proper
coverage upstream due to a few subtle things. Implementing this is
something we should do in libc++, however we'll first need to address
a few issues listed in https://reviews.llvm.org/D106124#3349710.

Differential Revision: https://reviews.llvm.org/D120683
2022-03-01 08:20:24 -05:00
Christopher Di Bella
5aaefa510e [libcxx][modules] protects users from relying on detail headers
libc++ has started splicing standard library headers into much more
fine-grained content for maintainability. It's very likely that outdated
and naive tooling (some of which is outside of LLVM's scope) will
suggest users include things such as <__ranges/access.h> instead of
<ranges>, and Hyrum's law suggests that users will eventually begin to
rely on this without the help of tooling. As such, this commit
intends to protect users from themselves, by making it a hard error for
anyone outside of the standard library to include libc++ detail headers.

Differential Revision: https://reviews.llvm.org/D106124
2022-02-26 09:00:25 +00:00
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
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
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
Louis Dionne
b4e88d4db1 [libc++][NFC] Rename _EnableIf to __enable_if_t for consistency
In other places in the code, we use lowercase spelling for things that
are not available in prior standards.

Differential Revision: https://reviews.llvm.org/D109435
2021-09-08 15:20:58 -04:00
Louis Dionne
3557c7c122 [libc++] Remove workarounds for [[nodebug]] not working properly on typedefs in older Clangs
Clang used to support [[nodebug]] everywhere except on typedefs. Since
we don't support such old Clangs anymore, we can get rid of _LIBCPP_NODEBUG_TYPE
in favour of always using _LIBCPP_NODEBUG.

Differential Revision: https://reviews.llvm.org/D108996
2021-09-01 10:51:09 -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
Christopher Di Bella
332da1c283 [libcxx][iwyu] ensures we IWYU as prep for modules
This has been broken out of D104170 since it should be merged whether or
not we go ahead with the module map changes.

Differential Revision: https://reviews.llvm.org/D104175
2021-06-15 19:43:25 +00:00
Petr Hosek
d9633f229c Revert "[libcxx][module-map] creates submodules for private headers"
This reverts commit f1417eb9b1f51b689c78dd8cb0114c1749dd2845 as it
uncovered a Clang bug PR50592.
2021-06-07 17:10:05 -07:00
Christopher Di Bella
f1417eb9b1 [libcxx][module-map] creates submodules for private headers
Most of our private headers need to be treated as submodules so that
Clang modules can export things correctly. Previous commits that split
monolithic headers into smaller chunks were unaware of this requirement,
and so this is being addressed in one fell swoop. Moving forward, most
new headers will need to have their own submodule (anything that's
conditionally included is exempt from this rule, which means `__support`
headers aren't made into submodules).

This hasn't been marked NFC, since I'm not 100% sure that's the case.

Differential Revision: https://reviews.llvm.org/D103551
2021-06-03 18:18:30 +00:00
Arthur O'Dwyer
6491d99e33 [libc++] Remove more unnecessary _VSTD:: from type names. NFCI.
Differential Revision: https://reviews.llvm.org/D102181
2021-05-11 12:23:55 -04:00
Louis Dionne
4cd6ca102a [libc++] NFC: Normalize #endif // comment indentation 2021-04-20 12:03:32 -04:00
Louis Dionne
f992cfba71 [libc++] Split up __memory/base.h into meaningful headers 2021-04-14 13:59:03 -04:00
Louis Dionne
b125392259 [libc++] NFC: Move unused include of <limits> to allocator_traits.h
The include should have been moved when I split allocator_traits.h out
of memory.
2021-04-09 15:31:55 -04:00
Louis Dionne
2cb4a96a99 [libc++] NFCI: Refactor allocator_traits
The implementation had a lot of boilerplate and was more complicated than
necessary. This NFC refactoring introduces a few macros to reduce code
duplication, and uses a consistent style and formatting for the whole file.

Differential Revision: https://reviews.llvm.org/D94544
2021-01-18 17:37:25 -05:00
Louis Dionne
7ad49aec12 [libc++] Split allocator_traits and pointer_traits out of <memory>
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
2020-12-14 16:13:57 -05:00