[all-commits] [llvm/llvm-project] 87784c: [libc++] Undeprecate the std::allocator<void> spec...

[Louis Dionne via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 87784cc6fb3453a17e0e7826b943a1d93cbfeccf
      https://github.com/llvm/llvm-project/commit/87784cc6fb3453a17e0e7826b943a1d93cbfeccf
  Author: Louis Dionne <ldionne.2 at gmail.com>
  Date:   2021-06-16 (Wed, 16 Jun 2021)

  Changed paths:
    M libcxx/docs/UsingLibcxx.rst
    M libcxx/include/__memory/allocator.h
    M libcxx/include/memory
    M libcxx/test/libcxx/depr/depr.default.allocator/allocator_types.cxx2a.pass.cpp
    R libcxx/test/libcxx/depr/depr.default.allocator/allocator_void.cxx2a.pass.cpp
    A libcxx/test/std/utilities/memory/default.allocator/PR50299.compile.pass.cpp
    M libcxx/test/std/utilities/memory/default.allocator/allocator.ctor.pass.cpp
    M libcxx/test/std/utilities/memory/default.allocator/allocator.dtor.pass.cpp
    M libcxx/test/std/utilities/memory/default.allocator/allocator_pointers.pass.cpp
    M libcxx/test/std/utilities/memory/default.allocator/allocator_types.deprecated_in_cxx17.verify.cpp
    M libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp
    M libcxx/test/std/utilities/memory/default.allocator/allocator_types.removed_in_cxx20.verify.cpp
    A libcxx/test/std/utilities/memory/default.allocator/allocator_types.void.compile.pass.cpp
    R libcxx/test/std/utilities/memory/default.allocator/allocator_void.deprecated_in_cxx17.verify.cpp

  Log Message:
  -----------
  [libc++] Undeprecate the std::allocator<void> specialization

While the std::allocator<void> specialization was deprecated by
https://wg21.link/p0174#2.2, the *use* of std::allocator<void> by users
was not. The intent was that std::allocator<void> could still be used
in C++17 and C++20, but starting with C++20 (with the removal of the
specialization), std::allocator<void> would use the primary template.
That intent was called out in wg21.link/p0619r4#3.9.

As a result of this patch, _LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS
will also not control whether the explicit specialization is provided or
not. It shouldn't matter, since in C++20, one can simply use the primary
template.

Fixes http://llvm.org/PR50299

Differential Revision: https://reviews.llvm.org/D104323