[libcxx-commits] [libcxx] 4e338dc - [libc++] P2389R2: `dextents` Index Type Parameter (#97393)
via libcxx-commits
libcxx-commits at lists.llvm.org
Mon Jul 15 08:23:38 PDT 2024
Author: Xiaoyang Liu
Date: 2024-07-15T11:23:34-04:00
New Revision: 4e338dce4de4ca1476e2b8f9c907769691a9093b
URL: https://github.com/llvm/llvm-project/commit/4e338dce4de4ca1476e2b8f9c907769691a9093b
DIFF: https://github.com/llvm/llvm-project/commit/4e338dce4de4ca1476e2b8f9c907769691a9093b.diff
LOG: [libc++] P2389R2: `dextents` Index Type Parameter (#97393)
This patch implements P2389R2, which was adopted at the St. Louis meeting.
It builds upon previous enhancements from P2299R3, which introduced deduction
guides and the `dextents` alias template.
Added:
libcxx/test/std/containers/views/mdspan/extents/dims.pass.cpp
Modified:
libcxx/docs/FeatureTestMacroTable.rst
libcxx/docs/ReleaseNotes/19.rst
libcxx/docs/Status/Cxx2cPapers.csv
libcxx/include/__mdspan/extents.h
libcxx/include/mdspan
libcxx/include/version
libcxx/test/std/language.support/support.limits/support.limits.general/mdspan.version.compile.pass.cpp
libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
libcxx/utils/generate_feature_test_macro_components.py
Removed:
################################################################################
diff --git a/libcxx/docs/FeatureTestMacroTable.rst b/libcxx/docs/FeatureTestMacroTable.rst
index 7cd20acc6ff4a..1e347d043ef69 100644
--- a/libcxx/docs/FeatureTestMacroTable.rst
+++ b/libcxx/docs/FeatureTestMacroTable.rst
@@ -446,6 +446,8 @@ Status
---------------------------------------------------------- -----------------
``__cpp_lib_linalg`` *unimplemented*
---------------------------------------------------------- -----------------
+ ``__cpp_lib_mdspan`` ``202406L``
+ ---------------------------------------------------------- -----------------
``__cpp_lib_optional_range_support`` *unimplemented*
---------------------------------------------------------- -----------------
``__cpp_lib_out_ptr`` *unimplemented*
diff --git a/libcxx/docs/ReleaseNotes/19.rst b/libcxx/docs/ReleaseNotes/19.rst
index e8b6cecf8f41e..e6d8acb74aeb2 100644
--- a/libcxx/docs/ReleaseNotes/19.rst
+++ b/libcxx/docs/ReleaseNotes/19.rst
@@ -54,6 +54,7 @@ Implemented Papers
- P2713R1 - Escaping improvements in ``std::format``
- P2231R1 - Missing ``constexpr`` in ``std::optional`` and ``std::variant``
- P0019R8 - ``std::atomic_ref``
+- P2389R2 - Alias template ``dims`` for the ``extents`` of ``mdspan``
Improvements and New Features
-----------------------------
diff --git a/libcxx/docs/Status/Cxx2cPapers.csv b/libcxx/docs/Status/Cxx2cPapers.csv
index aea413dd33588..2c498f336b125 100644
--- a/libcxx/docs/Status/Cxx2cPapers.csv
+++ b/libcxx/docs/Status/Cxx2cPapers.csv
@@ -65,7 +65,7 @@
"","","","","","",""
"`P2747R2 <https://wg21.link/P2747R2>`__","CWG","``constexpr`` placement new","St. Louis June 2024","","",""
"`P2997R1 <https://wg21.link/P2997R1>`__","LWG","Removing the common reference requirement from the indirectly invocable concepts","St. Louis June 2024","","",""
-"`P2389R2 <https://wg21.link/P2389R2>`__","LWG","``dextents`` Index Type Parameter","St. Louis June 2024","","",""
+"`P2389R2 <https://wg21.link/P2389R2>`__","LWG","``dextents`` Index Type Parameter","St. Louis June 2024","|Complete|","19.0",""
"`P3168R2 <https://wg21.link/P3168R2>`__","LWG","Give ``std::optional`` Range Support","St. Louis June 2024","","","|ranges|"
"`P3217R0 <https://wg21.link/P3217R0>`__","LWG","Adjoints to 'Enabling list-initialization for algorithms': find_last","St. Louis June 2024","","",""
"`P2985R0 <https://wg21.link/P2985R0>`__","LWG","A type trait for detecting virtual base classes","St. Louis June 2024","","",""
diff --git a/libcxx/include/__mdspan/extents.h b/libcxx/include/__mdspan/extents.h
index fea0decd8c6af..95082ef3d11ac 100644
--- a/libcxx/include/__mdspan/extents.h
+++ b/libcxx/include/__mdspan/extents.h
@@ -454,6 +454,12 @@ struct __make_dextents< _IndexType, 0, extents<_IndexType, _ExtentsPack...>> {
template <class _IndexType, size_t _Rank>
using dextents = typename __mdspan_detail::__make_dextents<_IndexType, _Rank>::type;
+# if _LIBCPP_STD_VER >= 26
+// [mdspan.extents.dims], alias template `dims`
+template <size_t _Rank, class _IndexType = size_t>
+using dims = dextents<_IndexType, _Rank>;
+# endif
+
// Deduction guide for extents
# if _LIBCPP_STD_VER >= 26
template <class... _IndexTypes>
diff --git a/libcxx/include/mdspan b/libcxx/include/mdspan
index 8d443f4acd1dd..aa7ba278b1aa0 100644
--- a/libcxx/include/mdspan
+++ b/libcxx/include/mdspan
@@ -20,6 +20,10 @@ namespace std {
template<class IndexType, size_t Rank>
using dextents = see below;
+ // [mdspan.extents.dims], alias template dims
+ template<size_t Rank, class IndexType = size_t>
+ using dims = see below; // since C++26
+
// [mdspan.layout], layout mapping
struct layout_left;
struct layout_right;
diff --git a/libcxx/include/version b/libcxx/include/version
index 1f66bce40df8a..c971336bcb85c 100644
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -159,7 +159,8 @@ __cpp_lib_make_unique 201304L <memory>
__cpp_lib_map_try_emplace 201411L <map>
__cpp_lib_math_constants 201907L <numbers>
__cpp_lib_math_special_functions 201603L <cmath>
-__cpp_lib_mdspan 202207L <mdspan>
+__cpp_lib_mdspan 202406L <mdspan>
+ 202207L // C++23
__cpp_lib_memory_resource 201603L <memory_resource>
__cpp_lib_move_iterator_concept 202207L <iterator>
__cpp_lib_move_only_function 202110L <functional>
@@ -530,6 +531,8 @@ __cpp_lib_void_t 201411L <type_traits>
// # define __cpp_lib_is_virtual_base_of 202406L
// # define __cpp_lib_is_within_lifetime 202306L
// # define __cpp_lib_linalg 202311L
+# undef __cpp_lib_mdspan
+# define __cpp_lib_mdspan 202406L
// # define __cpp_lib_optional_range_support 202406L
# undef __cpp_lib_out_ptr
// # define __cpp_lib_out_ptr 202311L
diff --git a/libcxx/test/std/containers/views/mdspan/extents/dims.pass.cpp b/libcxx/test/std/containers/views/mdspan/extents/dims.pass.cpp
new file mode 100644
index 0000000000000..e74bc0e66fca1
--- /dev/null
+++ b/libcxx/test/std/containers/views/mdspan/extents/dims.pass.cpp
@@ -0,0 +1,49 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+
+// <mdspan>
+
+// template<size_t Rank, class IndexType = size_t>
+// using dims = see below;
+//
+// Result: A type E that is a specialization of extents such that
+// E::rank() == Rank && E::rank() == E::rank_dynamic() is true,
+// and E::index_type denotes IndexType.
+
+#include <mdspan>
+#include <cstddef>
+
+#include "test_macros.h"
+
+template <class IndexType>
+void test_alias_template_dims() {
+ constexpr size_t D = std::dynamic_extent;
+ ASSERT_SAME_TYPE(std::dims<0, IndexType>, std::extents<IndexType>);
+ ASSERT_SAME_TYPE(std::dims<1, IndexType>, std::extents<IndexType, D>);
+ ASSERT_SAME_TYPE(std::dims<2, IndexType>, std::extents<IndexType, D, D>);
+ ASSERT_SAME_TYPE(std::dims<3, IndexType>, std::extents<IndexType, D, D, D>);
+ ASSERT_SAME_TYPE(std::dims<9, IndexType>, std::extents<IndexType, D, D, D, D, D, D, D, D, D>);
+}
+
+template <>
+void test_alias_template_dims<size_t>() {
+ constexpr size_t D = std::dynamic_extent;
+ ASSERT_SAME_TYPE(std::dims<0>, std::extents<size_t>);
+ ASSERT_SAME_TYPE(std::dims<1>, std::extents<size_t, D>);
+ ASSERT_SAME_TYPE(std::dims<2>, std::extents<size_t, D, D>);
+ ASSERT_SAME_TYPE(std::dims<3>, std::extents<size_t, D, D, D>);
+ ASSERT_SAME_TYPE(std::dims<9>, std::extents<size_t, D, D, D, D, D, D, D, D, D>);
+}
+
+int main(int, char**) {
+ test_alias_template_dims<int>();
+ test_alias_template_dims<unsigned int>();
+ test_alias_template_dims<size_t>();
+ return 0;
+}
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/mdspan.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/mdspan.version.compile.pass.cpp
index 4ef3382306421..64d1c99b223f4 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/mdspan.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/mdspan.version.compile.pass.cpp
@@ -18,6 +18,7 @@
/* Constant Value
__cpp_lib_freestanding_mdspan 202311L [C++26]
__cpp_lib_mdspan 202207L [C++23]
+ 202406L [C++26]
__cpp_lib_submdspan 202306L [C++26]
*/
@@ -115,8 +116,8 @@
# ifndef __cpp_lib_mdspan
# error "__cpp_lib_mdspan should be defined in c++26"
# endif
-# if __cpp_lib_mdspan != 202207L
-# error "__cpp_lib_mdspan should have the value 202207L in c++26"
+# if __cpp_lib_mdspan != 202406L
+# error "__cpp_lib_mdspan should have the value 202406L in c++26"
# endif
# if !defined(_LIBCPP_VERSION)
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
index aa5ff80afb56a..a01ee702a5172 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
@@ -147,6 +147,7 @@
__cpp_lib_math_constants 201907L [C++20]
__cpp_lib_math_special_functions 201603L [C++17]
__cpp_lib_mdspan 202207L [C++23]
+ 202406L [C++26]
__cpp_lib_memory_resource 201603L [C++17]
__cpp_lib_modules 202207L [C++23]
__cpp_lib_move_iterator_concept 202207L [C++20]
@@ -7289,8 +7290,8 @@
# ifndef __cpp_lib_mdspan
# error "__cpp_lib_mdspan should be defined in c++26"
# endif
-# if __cpp_lib_mdspan != 202207L
-# error "__cpp_lib_mdspan should have the value 202207L in c++26"
+# if __cpp_lib_mdspan != 202406L
+# error "__cpp_lib_mdspan should have the value 202406L in c++26"
# endif
# if !defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_PMR
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index 7bc11aa401829..773b1523cde4e 100755
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -868,7 +868,7 @@ def add_version_header(tc):
"name": "__cpp_lib_mdspan",
"values": {
"c++23": 202207,
- # "c++26": 202406, # P2389R2 dextents Index Type Parameter
+ "c++26": 202406, # P2389R2 dextents Index Type Parameter
},
"headers": ["mdspan"],
},
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