[libcxx-commits] [libcxx] [libc++][memory] P2868R1: Removing deprecated typedef `std::allocator::is_always_equal` (PR #78562)
via libcxx-commits
libcxx-commits at lists.llvm.org
Thu Jan 18 06:09:23 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libcxx
Author: Hristo Hristov (H-G-Hristov)
<details>
<summary>Changes</summary>
Implements:
- https://wg21.link/P2868R1
- https://wg21.link/LWG3170
---
Full diff: https://github.com/llvm/llvm-project/pull/78562.diff
10 Files Affected:
- (modified) libcxx/.clang-format (+1)
- (modified) libcxx/docs/ReleaseNotes/18.rst (+4)
- (modified) libcxx/docs/Status/Cxx23Issues.csv (+1-1)
- (modified) libcxx/docs/Status/Cxx2cPapers.csv (+1-1)
- (modified) libcxx/docs/UsingLibcxx.rst (+3)
- (modified) libcxx/include/__memory/allocator.h (+6-2)
- (modified) libcxx/include/memory (+1-1)
- (added) libcxx/test/std/utilities/memory/default.allocator/allocator_types.deprecated_in_cxx23.verify.cpp (+32)
- (modified) libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp (+2)
- (added) libcxx/test/std/utilities/memory/default.allocator/allocator_types.removed_in_cxx26.verify.cpp (+34)
``````````diff
diff --git a/libcxx/.clang-format b/libcxx/.clang-format
index 56bdf2b5f91165..39ae1322ffa8a6 100644
--- a/libcxx/.clang-format
+++ b/libcxx/.clang-format
@@ -28,6 +28,7 @@ AttributeMacros: [
'_LIBCPP_DEPRECATED_IN_CXX14',
'_LIBCPP_DEPRECATED_IN_CXX17',
'_LIBCPP_DEPRECATED_IN_CXX20',
+ '_LIBCPP_DEPRECATED_IN_CXX23',
'_LIBCPP_DEPRECATED',
'_LIBCPP_DISABLE_EXTENTSION_WARNING',
'_LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION',
diff --git a/libcxx/docs/ReleaseNotes/18.rst b/libcxx/docs/ReleaseNotes/18.rst
index 77b7939a0c0ac9..a30451a2e19e2b 100644
--- a/libcxx/docs/ReleaseNotes/18.rst
+++ b/libcxx/docs/ReleaseNotes/18.rst
@@ -60,6 +60,7 @@ Implemented Papers
- P0521R0 - Proposed Resolution for CA 14 (``shared_ptr`` ``use_count/unique``)
- P1759R6 - Native handles and file streams
- P2517R1 - Add a conditional ``noexcept`` specification to ``std::apply``
+- P2868R3 - Remove Deprecated ``std::allocator`` Typedef From C++26
Improvements and New Features
@@ -89,6 +90,9 @@ Improvements and New Features
- The ``_LIBCPP_ENABLE_CXX20_REMOVED_SHARED_PTR_UNIQUE`` macro has been added to make
the function ``std::shared_ptr<...>::unique()`` available.
+- The ``_LIBCPP_ENABLE_CXX26_REMOVED_ALLOCATOR_MEMBERS`` macro has been added to make
+ the function ``allocator<T>::is_always_equal`` available.
+
- The cmake option ``LIBCXX_ENABLE_STD_MODULES`` has been removed. The test
infrastructure no longer depends on a modern CMake, it works with the minimal
required LLVM version (3.20.0).
diff --git a/libcxx/docs/Status/Cxx23Issues.csv b/libcxx/docs/Status/Cxx23Issues.csv
index b24ecc5525a149..70480b33820580 100644
--- a/libcxx/docs/Status/Cxx23Issues.csv
+++ b/libcxx/docs/Status/Cxx23Issues.csv
@@ -15,7 +15,7 @@
"`2743 <https://wg21.link/LWG2743>`__","P0083R3 ``node_handle`` private members missing ""exposition only"" comment","November 2020","|Nothing To Do|",""
"`2820 <https://wg21.link/LWG2820>`__","Clarify ``<cstdint>`` macros","November 2020","|Nothing To Do|",""
"`3120 <https://wg21.link/LWG3120>`__","Unclear behavior of ``monotonic_buffer_resource::release()``","November 2020","",""
-"`3170 <https://wg21.link/LWG3170>`__","``is_always_equal`` added to ``std::allocator`` makes the standard library treat derived types as always equal","November 2020","",""
+"`3170 <https://wg21.link/LWG3170>`__","``is_always_equal`` added to ``std::allocator`` makes the standard library treat derived types as always equal","November 2020","|Complete|","18.0"
"`3036 <https://wg21.link/LWG3036>`__","``polymorphic_allocator::destroy`` is extraneous","November 2020","",""
"`3171 <https://wg21.link/LWG3171>`__","LWG2989 breaks ``directory_entry`` stream insertion","November 2020","|Complete|","14.0"
"`3306 <https://wg21.link/LWG3306>`__","``ranges::advance`` violates its preconditions","November 2020","|Complete|","14.0","|ranges|"
diff --git a/libcxx/docs/Status/Cxx2cPapers.csv b/libcxx/docs/Status/Cxx2cPapers.csv
index 5701717f39766c..762cbc6d487c69 100644
--- a/libcxx/docs/Status/Cxx2cPapers.csv
+++ b/libcxx/docs/Status/Cxx2cPapers.csv
@@ -36,7 +36,7 @@
"`P0952R2 <https://wg21.link/P0952R2>`__","LWG","A new specification for ``std::generate_canonical``","Kona November 2023","","",""
"`P2447R6 <https://wg21.link/P2447R6>`__","LWG","``std::span`` over an initializer list","Kona November 2023","","",""
"`P2821R5 <https://wg21.link/P2821R5>`__","LWG","``span.at()``","Kona November 2023","|Complete|","18.0",""
-"`P2868R3 <https://wg21.link/P2868R3>`__","LWG","Remove Deprecated ``std::allocator`` Typedef From C++26","Kona November 2023","","",""
+"`P2868R3 <https://wg21.link/P2868R3>`__","LWG","Remove Deprecated ``std::allocator`` Typedef From C++26","Kona November 2023","|Complete|","18.0",""
"`P2870R3 <https://wg21.link/P2870R3>`__","LWG","Remove ``basic_string::reserve()`` From C++26","Kona November 2023","|Complete|","18.0",""
"`P2871R3 <https://wg21.link/P2871R3>`__","LWG","Remove Deprecated Unicode Conversion Facets from C++26","Kona November 2023","|Complete|","18.0",""
"`P2819R2 <https://wg21.link/P2819R2>`__","LWG","Add tuple protocol to complex","Kona November 2023","","",""
diff --git a/libcxx/docs/UsingLibcxx.rst b/libcxx/docs/UsingLibcxx.rst
index daf39c9faa449a..3b1be286c16981 100644
--- a/libcxx/docs/UsingLibcxx.rst
+++ b/libcxx/docs/UsingLibcxx.rst
@@ -283,6 +283,9 @@ C++26 Specific Configuration Macros
This macro is used to re-enable the function
``std::basic_string<...>::reserve()``.
+**_LIBCPP_ENABLE_CXX26_REMOVED_ALLOCATOR_MEMBERS**:
+ This macro is used to re-enable redundant member of ``allocator<T>::is_always_equal``
+
Libc++ Extensions
=================
diff --git a/libcxx/include/__memory/allocator.h b/libcxx/include/__memory/allocator.h
index 8d54e0f0897dda..4e6303914c38aa 100644
--- a/libcxx/include/__memory/allocator.h
+++ b/libcxx/include/__memory/allocator.h
@@ -107,7 +107,9 @@ class _LIBCPP_TEMPLATE_VIS allocator : private __non_trivial_if<!is_void<_Tp>::v
typedef ptrdiff_t difference_type;
typedef _Tp value_type;
typedef true_type propagate_on_container_move_assignment;
- typedef true_type is_always_equal;
+#if _LIBCPP_STD_VER <= 23 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_ALLOCATOR_MEMBERS)
+ _LIBCPP_DEPRECATED_IN_CXX23 typedef true_type is_always_equal;
+#endif
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 allocator() _NOEXCEPT = default;
@@ -185,7 +187,9 @@ class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
typedef ptrdiff_t difference_type;
typedef const _Tp value_type;
typedef true_type propagate_on_container_move_assignment;
- typedef true_type is_always_equal;
+#if _LIBCPP_STD_VER <= 23 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_ALLOCATOR_MEMBERS)
+ _LIBCPP_DEPRECATED_IN_CXX23 typedef true_type is_always_equal;
+#endif
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 allocator() _NOEXCEPT = default;
diff --git a/libcxx/include/memory b/libcxx/include/memory
index ee245d5fd2dcb2..19c11ee9498728 100644
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -139,7 +139,7 @@ public:
template <class U> struct rebind {typedef allocator<U> other;}; // deprecated in C++17, removed in C++20
typedef true_type propagate_on_container_move_assignment;
- typedef true_type is_always_equal;
+ typedef true_type is_always_equal; // Deprecated in C++23, removed in C++26
constexpr allocator() noexcept; // constexpr in C++20
constexpr allocator(const allocator&) noexcept; // constexpr in C++20
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator_types.deprecated_in_cxx23.verify.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator_types.deprecated_in_cxx23.verify.cpp
new file mode 100644
index 00000000000000..b5db7ca9648b6e
--- /dev/null
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator_types.deprecated_in_cxx23.verify.cpp
@@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: c++23
+
+// <memory>
+
+// template <class T>
+// class allocator
+// {
+// ...
+// typedef true_type is_always_equal; // Deprecated in C++23, removed in C++26
+// ...
+// };
+
+#include <memory>
+
+template <typename T>
+void check() {
+ typedef std::allocator<char>::is_always_equal IAE; // expected-warning {{'is_always_equal' is deprecated}}
+}
+
+void test() {
+ check<char>();
+ check<char const>();
+ check<void>();
+}
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp
index 74adc6943594dc..7085a1d3fc602f 100644
--- a/libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator_types.pass.cpp
@@ -46,7 +46,9 @@ void test() {
static_assert((std::is_same<typename Alloc::difference_type, std::ptrdiff_t>::value), "");
static_assert((std::is_same<typename Alloc::value_type, T>::value), "");
static_assert((std::is_same<typename Alloc::propagate_on_container_move_assignment, std::true_type>::value), "");
+#if TEST_STD_VER <= 23
static_assert((std::is_same<typename Alloc::is_always_equal, std::true_type>::value), "");
+#endif
#if TEST_STD_VER <= 17
static_assert((std::is_same<typename Alloc::pointer, T*>::value), "");
diff --git a/libcxx/test/std/utilities/memory/default.allocator/allocator_types.removed_in_cxx26.verify.cpp b/libcxx/test/std/utilities/memory/default.allocator/allocator_types.removed_in_cxx26.verify.cpp
new file mode 100644
index 00000000000000..e26536f196e4f9
--- /dev/null
+++ b/libcxx/test/std/utilities/memory/default.allocator/allocator_types.removed_in_cxx26.verify.cpp
@@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20, c++23
+
+// <memory>
+
+// Check that the following nested types are removed in C++20:
+
+// template <class T>
+// class allocator
+// {
+// ...
+// typedef true_type is_always_equal; // Deprecated in C++23, removed in C++26
+// ...
+// };
+
+#include <memory>
+
+template <typename T>
+void check() {
+ using IAE = typename std::allocator<T>::is_always_equal; // expected-error 3 {{no type named 'is_always_equal'}}
+}
+
+void test() {
+ check<char>();
+ check<char const>();
+ check<void>();
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/78562
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