[libc++] Bump __cpp_lib_constexpr_algorithms for P2562R1 in C++26 (llvm#132075)

Completes P2562R1.

Author: frederick-vs-ja

libcxx/docs/FeatureTestMacroTable.rst

@@ -416,6 +416,8 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_bitset``                                       ``202306L``
     ---------------------------------------------------------- -----------------
+    ``__cpp_lib_constexpr_algorithms``                         ``202306L``
+    ---------------------------------------------------------- -----------------
     ``__cpp_lib_constexpr_new``                                ``202406L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_constrained_equality``                         *unimplemented*

libcxx/docs/ReleaseNotes/21.rst

@@ -42,6 +42,7 @@ Implemented Papers
 - P0767R1: Deprecate POD (`Github <https://github.com/llvm/llvm-project/issues/104013>`__)
 - P1361R2: Integration of chrono with text formatting (`Github <https://github.com/llvm/llvm-project/issues/100014>`__)
 - P2255R2: A type trait to detect reference binding to temporary (implemented the type traits only) (`Github <https://github.com/llvm/llvm-project/issues/105180>`__)
+- P2562R1: ``constexpr`` Stable Sorting (`Github <https://github.com/llvm/llvm-project/issues/105360>`__)
 
 Improvements and New Features
 -----------------------------

libcxx/docs/Status/Cxx2cPapers.csv

@@ -2,7 +2,7 @@
 "`P2497R0 <https://wg21.link/P2497R0>`__","Testing for success or failure of ``<charconv>`` functions","2023-06 (Varna)","|Complete|","18",""
 "`P2592R3 <https://wg21.link/P2592R3>`__","Hashing support for ``std::chrono`` value classes","2023-06 (Varna)","","",""
 "`P2587R3 <https://wg21.link/P2587R3>`__","``to_string`` or not ``to_string``","2023-06 (Varna)","","",""
-"`P2562R1 <https://wg21.link/P2562R1>`__","``constexpr`` Stable Sorting","2023-06 (Varna)","|Partial|","20",""
+"`P2562R1 <https://wg21.link/P2562R1>`__","``constexpr`` Stable Sorting","2023-06 (Varna)","|Complete|","21",""
 "`P2545R4 <https://wg21.link/P2545R4>`__","Read-Copy Update (RCU)","2023-06 (Varna)","","",""
 "`P2530R3 <https://wg21.link/P2530R3>`__","Hazard Pointers for C++26","2023-06 (Varna)","","",""
 "`P2538R1 <https://wg21.link/P2538R1>`__","ADL-proof ``std::projected``","2023-06 (Varna)","|Complete|","18",""

libcxx/include/version

@@ -60,7 +60,8 @@ __cpp_lib_chrono_udls                                   201304L <chrono>
 __cpp_lib_clamp                                         201603L <algorithm>
 __cpp_lib_complex_udls                                  201309L <complex>
 __cpp_lib_concepts                                      202002L <concepts>
-__cpp_lib_constexpr_algorithms                          201806L <algorithm> <utility>
+__cpp_lib_constexpr_algorithms                          202306L <algorithm> <utility>
+                                                        201806L // C++20
 __cpp_lib_constexpr_bitset                              202207L <bitset>
 __cpp_lib_constexpr_charconv                            202207L <charconv>
 __cpp_lib_constexpr_cmath                               202202L <cmath> <cstdlib>
@@ -536,6 +537,8 @@ __cpp_lib_void_t                                        201411L <type_traits>
 # undef  __cpp_lib_bind_front
 # define __cpp_lib_bind_front                           202306L
 # define __cpp_lib_bitset                               202306L
+# undef  __cpp_lib_constexpr_algorithms
+# define __cpp_lib_constexpr_algorithms                 202306L
 # if !defined(_LIBCPP_ABI_VCRUNTIME)
 #   define __cpp_lib_constexpr_new                      202406L
 # endif

libcxx/test/std/language.support/support.limits/support.limits.general/algorithm.version.compile.pass.cpp

@@ -18,6 +18,7 @@
 /*  Constant                                                Value
     __cpp_lib_clamp                                         201603L [C++17]
     __cpp_lib_constexpr_algorithms                          201806L [C++20]
+                                                            202306L [C++26]
     __cpp_lib_default_template_type_for_algorithm_values    202403L [C++26]
     __cpp_lib_freestanding_algorithm                        202311L [C++26]
     __cpp_lib_parallel_algorithm                            201603L [C++17]
@@ -380,8 +381,8 @@
 # ifndef __cpp_lib_constexpr_algorithms
 #   error "__cpp_lib_constexpr_algorithms should be defined in c++26"
 # endif
-# if __cpp_lib_constexpr_algorithms != 201806L
-#   error "__cpp_lib_constexpr_algorithms should have the value 201806L in c++26"
+# if __cpp_lib_constexpr_algorithms != 202306L
+#   error "__cpp_lib_constexpr_algorithms should have the value 202306L in c++26"
 # endif
 
 # if !defined(_LIBCPP_VERSION)

libcxx/test/std/language.support/support.limits/support.limits.general/utility.version.compile.pass.cpp

@@ -18,6 +18,7 @@
 /*  Constant                                  Value
     __cpp_lib_as_const                        201510L [C++17]
     __cpp_lib_constexpr_algorithms            201806L [C++20]
+                                              202306L [C++26]
     __cpp_lib_constexpr_utility               201811L [C++20]
     __cpp_lib_constrained_equality            202403L [C++26]
     __cpp_lib_exchange_function               201304L [C++14]
@@ -407,8 +408,8 @@
 # ifndef __cpp_lib_constexpr_algorithms
 #   error "__cpp_lib_constexpr_algorithms should be defined in c++26"
 # endif
-# if __cpp_lib_constexpr_algorithms != 201806L
-#   error "__cpp_lib_constexpr_algorithms should have the value 201806L in c++26"
+# if __cpp_lib_constexpr_algorithms != 202306L
+#   error "__cpp_lib_constexpr_algorithms should have the value 202306L in c++26"
 # endif
 
 # ifndef __cpp_lib_constexpr_utility

libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp

@@ -56,6 +56,7 @@
     __cpp_lib_complex_udls                                  201309L [C++14]
     __cpp_lib_concepts                                      202002L [C++20]
     __cpp_lib_constexpr_algorithms                          201806L [C++20]
+                                                            202306L [C++26]
     __cpp_lib_constexpr_bitset                              202207L [C++23]
     __cpp_lib_constexpr_charconv                            202207L [C++23]
     __cpp_lib_constexpr_cmath                               202202L [C++23]
@@ -6565,8 +6566,8 @@
 # ifndef __cpp_lib_constexpr_algorithms
 #   error "__cpp_lib_constexpr_algorithms should be defined in c++26"
 # endif
-# if __cpp_lib_constexpr_algorithms != 201806L
-#   error "__cpp_lib_constexpr_algorithms should have the value 201806L in c++26"
+# if __cpp_lib_constexpr_algorithms != 202306L
+#   error "__cpp_lib_constexpr_algorithms should have the value 202306L in c++26"
 # endif
 
 # ifndef __cpp_lib_constexpr_bitset

libcxx/utils/generate_feature_test_macro_components.py

@@ -320,7 +320,7 @@ def add_version_header(tc):
             "name": "__cpp_lib_constexpr_algorithms",
             "values": {
                 "c++20": 201806,
-                # "c++26": 202306, # P2562R1 constexpr Stable Sorting
+                "c++26": 202306,
             },
             "headers": ["algorithm", "utility"],
         },