P0009R18 <mdspan>

stl/CMakeLists.txt

@@ -177,6 +177,7 @@ set(HEADERS
     ${CMAKE_CURRENT_LIST_DIR}/inc/list
     ${CMAKE_CURRENT_LIST_DIR}/inc/locale
     ${CMAKE_CURRENT_LIST_DIR}/inc/map
+    ${CMAKE_CURRENT_LIST_DIR}/inc/mdspan
     ${CMAKE_CURRENT_LIST_DIR}/inc/memory
     ${CMAKE_CURRENT_LIST_DIR}/inc/memory_resource
     ${CMAKE_CURRENT_LIST_DIR}/inc/mutex

stl/inc/__msvc_all_public_headers.hpp

@@ -107,6 +107,7 @@
 #include <list>
 #include <locale>
 #include <map>
+#include <mdspan>
 #include <memory>
 #include <memory_resource>
 #include <new>

stl/inc/header-units.json

@@ -83,6 +83,7 @@
         "list",
         "locale",
         "map",
+        "mdspan",
         "memory",
         "memory_resource",
         "mutex",

stl/inc/yvals_core.h

@@ -314,6 +314,7 @@
 // Other C++20 deprecation warnings
 
 // _HAS_CXX23 directly controls:
+// P0009R18 <mdspan>
 // P0288R9 move_only_function
 // P0323R12 <expected>
 // P0401R6 Providing Size Feedback In The Allocator Interface
@@ -374,9 +375,13 @@
 // P2539R4 Synchronizing print() With The Underlying Stream
 // P2540R1 Empty Product For Certain Views
 // P2549R1 unexpected<E>::error()
+// P2599R2 mdspan: index_type, size_type
+// P2604R0 mdspan: data_handle_type, data_handle(), exhaustive
+// P2613R1 mdspan: empty()
 // P2652R2 Disallowing User Specialization Of allocator_traits
 // P2693R1 Formatting thread::id And stacktrace
 // P2713R1 Escaping Improvements In std::format
+// P2763R1 Fixing layout_stride's Default Constructor For Fully Static Extents
 
 // _HAS_CXX23 and _SILENCE_ALL_CXX23_DEPRECATION_WARNINGS control:
 // P1413R3 Deprecate aligned_storage And aligned_union
@@ -1787,6 +1792,10 @@ _EMIT_STL_ERROR(STL1004, "C++98 unexpected() is incompatible with C++23 unexpect
 #define __cpp_lib_ios_noreplace  202207L
 #define __cpp_lib_is_scoped_enum 202011L
 
+#ifdef __cpp_lib_concepts
+#define __cpp_lib_mdspan 202207L
+#endif // defined(__cpp_lib_concepts)
+
 #if !defined(__clang__) && !defined(__EDG__) // TRANSITION, Clang and EDG support for modules
 #define __cpp_lib_modules 202207L
 #endif // !defined(__clang__) && !defined(__EDG__)

stl/modules/std.ixx

@@ -76,6 +76,7 @@ export module std;
 #include <list>
 #include <locale>
 #include <map>
+#include <mdspan>
 #include <memory>
 #include <memory_resource>
 #include <mutex>

tests/std/include/test_header_units_and_modules.hpp

@@ -389,6 +389,17 @@ void test_map() {
     assert(m[30] == 33);
 }
 
+void test_mdspan() {
+    using namespace std;
+    puts("Testing <mdspan>.");
+    int arr[] = {10, 0, 0, 0, 20, 0, 0, 0, 30};
+    layout_right::mapping<extents<int, 3, 3>> mp;
+    assert(arr[mp(0, 0)] == 10);
+    assert(arr[mp(1, 1)] == 20);
+    assert(arr[mp(2, 2)] == 30);
+    // TRANSITION, test std::mdspan too (DevCom-10359857)
+}
+
 void test_memory() {
     using namespace std;
     puts("Testing <memory>.");
@@ -1099,6 +1110,7 @@ void all_cpp_header_tests() {
     test_list();
     test_locale();
     test_map();
+    test_mdspan();
     test_memory();
     test_memory_resource();
     test_mutex();