[libc++] Updates C++2b to C++23.

During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.

This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.

Note since we use clang-tidy 16 a small work-around is needed. Clang
knows -std=c++23 but clang-tidy not so for now force the lit compiler
flag to use -std=c++2b instead of -std=c++23.

Reviewed By: #libc, philnik, jloser, ldionne

Differential Revision: https://reviews.llvm.org/D150795

libcxx/cmake/caches/Generic-cxx2b.cmake → libcxx/cmake/caches/Generic-cxx23.cmake

@@ -1,2 +1,2 @@
-set(LIBCXX_TEST_PARAMS "std=c++2b" CACHE STRING "")
+set(LIBCXX_TEST_PARAMS "std=c++23" CACHE STRING "")
 set(LIBCXXABI_TEST_PARAMS "${LIBCXX_TEST_PARAMS}" CACHE STRING "")

libcxx/docs/FeatureTestMacroTable.rst

@@ -298,7 +298,7 @@ Status
     ------------------------------------------------- -----------------
     ``__cpp_lib_unwrap_ref``                          ``201811L``
     ------------------------------------------------- -----------------
-    **C++ 2b**
+    **C++ 23**
     -------------------------------------------------------------------
     ``__cpp_lib_adaptor_iterator_pair_constructor``   ``202106L``
     ------------------------------------------------- -----------------

libcxx/docs/ReleaseNotes.rst

@@ -70,7 +70,7 @@ Deprecations and Removals
   includes are removed based on the language version used. Incidental transitive
   inclusions of the following headers have been removed:
 
-  - C++2b: ``atomic``, ``bit``, ``cstdint``, ``cstdlib``, ``cstring``, ``initializer_list``, ``limits``, ``new``,
+  - C++23: ``atomic``, ``bit``, ``cstdint``, ``cstdlib``, ``cstring``, ``initializer_list``, ``limits``, ``new``,
            ``stdexcept``, ``system_error``, ``type_traits``, ``typeinfo``
 
 - ``<algorithm>`` no longer includes ``<chrono>`` in any C++ version (it was previously included in C++17 and earlier).

libcxx/docs/Status/Cxx2b.rst → libcxx/docs/Status/Cxx23.rst

@@ -1,7 +1,7 @@
-.. _cxx2b-status:
+.. _cxx23-status:
 
 ================================
-libc++ C++2b Status
+libc++ C++23 Status
 ================================
 
 .. include:: ../Helpers/Styles.rst
@@ -14,6 +14,7 @@ Overview
 ================================
 
 In November 2020, the C++ standard committee adopted the first changes to the next version of the C++ standard, known here as "C++2b" (probably to be C++23).
+In February 2023, the C++ standard committee approved this draft, and sent it to ISO for approval as C++23.
 
 This page shows the status of libc++; the status of clang's support of the language features is `here <https://clang.llvm.org/cxx_status.html#cxx23>`__.
 
@@ -27,13 +28,13 @@ The groups that have contributed papers:
 
 .. note:: "Nothing to do" means that no library changes were needed to implement this change.
 
-.. _paper-status-cxx2b:
+.. _paper-status-cxx23:
 
 Paper Status
 ====================================
 
 .. csv-table::
-   :file: Cxx2bPapers.csv
+   :file: Cxx23Papers.csv
    :header-rows: 1
    :widths: auto
 
@@ -48,13 +49,13 @@ Paper Status
       The formatter for ``stacktrace`` is not implemented, since ``stacktrace`` is
       not implemented yet.
 
-.. _issues-status-cxx2b:
+.. _issues-status-cxx23:
 
 Library Working Group Issues Status
 ====================================
 
 .. csv-table::
-   :file: Cxx2bIssues.csv
+   :file: Cxx23Issues.csv
    :header-rows: 1
    :widths: auto
 

libcxx/docs/Status/Zip.rst

@@ -12,7 +12,7 @@ libc++ Zip Status (P2321R2)
 Overview
 ========
 
-This document contains the status of the C++2b zip implementation in libc++.
+This document contains the status of the C++23 zip implementation in libc++.
 It is used to track both the status of the sub-projects of the effort and who
 is assigned to these sub-projects. This avoids duplicating effort.
 

libcxx/docs/index.rst

@@ -42,7 +42,7 @@ Getting Started with libc++
    Status/Cxx14
    Status/Cxx17
    Status/Cxx20
-   Status/Cxx2b
+   Status/Cxx23
    Status/Format
    Status/Parallelism
    Status/Ranges
@@ -145,7 +145,7 @@ C++ Dialect Support
 * :ref:`C++14 - Complete <cxx14-status>`
 * :ref:`C++17 - In Progress <cxx17-status>`
 * :ref:`C++20 - In Progress <cxx20-status>`
-* :ref:`C++2b - In Progress <cxx2b-status>`
+* :ref:`C++23 - In Progress <cxx23-status>`
 * :ref:`C++ Feature Test Macro Status <feature-status>`
 
 

libcxx/include/__config

@@ -61,9 +61,11 @@
 #      define _LIBCPP_STD_VER 17
 #    elif __cplusplus <= 202002L
 #      define _LIBCPP_STD_VER 20
+#    elif __cplusplus <= 202302L
+#      define _LIBCPP_STD_VER 23
 #    else
 // Expected release year of the next C++ standard
-#      define _LIBCPP_STD_VER 23
+#      define _LIBCPP_STD_VER 26
 #    endif
 #  endif // _LIBCPP_STD_VER
 // NOLINTEND(libcpp-cpp-version-check)

libcxx/include/ranges

@@ -294,13 +294,13 @@ namespace std::ranges {
   // [range.zip], zip view
   template<input_range... Views>
     requires (view<Views> && ...) && (sizeof...(Views) > 0)
-  class zip_view;        // C++2b
+  class zip_view;        // C++23
 
   template<class... Views>
-    inline constexpr bool enable_borrowed_range<zip_view<Views...>> =    // C++2b
+    inline constexpr bool enable_borrowed_range<zip_view<Views...>> =    // C++23
       (enable_borrowed_range<Views> && ...);
 
-  namespace views { inline constexpr unspecified zip = unspecified; }    // C++2b
+  namespace views { inline constexpr unspecified zip = unspecified; }    // C++23
 
   // [range.as.rvalue]
   template <view V>

libcxx/include/string

@@ -119,7 +119,7 @@ public:
         explicit basic_string(const T& t, const Allocator& a = Allocator());                    // C++17, constexpr since C++20
     basic_string(const value_type* s, const allocator_type& a = allocator_type());              // constexpr since C++20
     basic_string(const value_type* s, size_type n, const allocator_type& a = allocator_type()); // constexpr since C++20
-    basic_string(nullptr_t) = delete; // C++2b
+    basic_string(nullptr_t) = delete; // C++23
     basic_string(size_type n, value_type c, const allocator_type& a = allocator_type());        // constexpr since C++20
     template<class InputIterator>
         basic_string(InputIterator begin, InputIterator end,
@@ -140,7 +140,7 @@ public:
              allocator_type::propagate_on_container_move_assignment::value ||
              allocator_type::is_always_equal::value );                                          // C++17, constexpr since C++20
     basic_string& operator=(const value_type* s);                                               // constexpr since C++20
-    basic_string& operator=(nullptr_t) = delete; // C++2b
+    basic_string& operator=(nullptr_t) = delete; // C++23
     basic_string& operator=(value_type c);                                                      // constexpr since C++20
     basic_string& operator=(initializer_list<value_type>);                                      // constexpr since C++20
 
@@ -342,9 +342,9 @@ public:
     constexpr bool ends_with(charT c) const noexcept;                                           // C++20
     constexpr bool ends_with(const charT* s) const;                                             // C++20
 
-    constexpr bool contains(basic_string_view<charT, traits> sv) const noexcept;                // C++2b
-    constexpr bool contains(charT c) const noexcept;                                            // C++2b
-    constexpr bool contains(const charT* s) const;                                              // C++2b
+    constexpr bool contains(basic_string_view<charT, traits> sv) const noexcept;                // C++23
+    constexpr bool contains(charT c) const noexcept;                                            // C++23
+    constexpr bool contains(const charT* s) const;                                              // C++23
 };
 
 template<class InputIterator,

libcxx/include/string_view

@@ -90,7 +90,7 @@ namespace std {
       basic_string_view& operator=(const basic_string_view&) noexcept = default;
       template<class Allocator>
       constexpr basic_string_view(const charT* str);
-      basic_string_view(nullptr_t) = delete; // C++2b
+      basic_string_view(nullptr_t) = delete; // C++23
       constexpr basic_string_view(const charT* str, size_type len);
       template <class It, class End>
       constexpr basic_string_view(It begin, End end); // C++20
@@ -168,9 +168,9 @@ namespace std {
       constexpr bool ends_with(charT c) const noexcept;               // C++20
       constexpr bool ends_with(const charT* s) const;                 // C++20
 
-      constexpr bool contains(basic_string_view s) const noexcept; // C++2b
-      constexpr bool contains(charT c) const noexcept;             // C++2b
-      constexpr bool contains(const charT* s) const;               // C++2b
+      constexpr bool contains(basic_string_view s) const noexcept; // C++23
+      constexpr bool contains(charT c) const noexcept;             // C++23
+      constexpr bool contains(const charT* s) const;               // C++23
 
      private:
       const_pointer data_;  // exposition only

libcxx/include/type_traits

@@ -51,7 +51,7 @@ namespace std
     template <class T> struct is_arithmetic;
     template <class T> struct is_fundamental;
     template <class T> struct is_member_pointer;
-    template <class T> struct is_scoped_enum; // C++2b
+    template <class T> struct is_scoped_enum; // C++23
     template <class T> struct is_scalar;
     template <class T> struct is_object;
     template <class T> struct is_compound;
@@ -286,7 +286,7 @@ namespace std
       template <class T> inline constexpr bool is_member_pointer_v
         = is_member_pointer<T>::value;                                   // C++17
       template <class T> inline constexpr bool is_scoped_enum_v
-        = is_scoped_enum<T>::value;                                      // C++2b
+        = is_scoped_enum<T>::value;                                      // C++23
 
       // See C++14 20.10.4.3, type properties
       template <class T> inline constexpr bool is_const_v

libcxx/include/utility

@@ -240,7 +240,7 @@ template <size_t I>
 
 // [utility.underlying], to_underlying
 template <class T>
-    constexpr underlying_type_t<T> to_underlying( T value ) noexcept; // C++2b
+    constexpr underlying_type_t<T> to_underlying( T value ) noexcept; // C++23
 
 }  // std
 

libcxx/test/libcxx/numerics/c.math/constexpr-cxx2b-clang.pass.cpp → libcxx/test/libcxx/numerics/c.math/constexpr-cxx23-clang.pass.cpp

@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 // Check that Clang supports constexpr <cmath> and <cstdlib> functions
-// mentioned in the P0533R9 paper that is part of C++2b
+// mentioned in the P0533R9 paper that is part of C++23
 // (https://wg21.link/p0533r9)
 //
 // Every function called in this test should become constexpr. Whenever some

libcxx/test/libcxx/numerics/c.math/constexpr-cxx2b-gcc.pass.cpp → libcxx/test/libcxx/numerics/c.math/constexpr-cxx23-gcc.pass.cpp

@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 // Check that GCC supports constexpr <cmath> and <cstdlib> functions
-// mentioned in the P0533R9 paper that is part of C++2b
+// mentioned in the P0533R9 paper that is part of C++23
 // (https://wg21.link/p0533r9)
 //
 // Every function called in this test should become constexpr. Whenever some

libcxx/test/libcxx/transitive_includes.sh.cpp

@@ -40,7 +40,7 @@ import re
 # To re-generate the list of expected headers, temporarily set this to True, re-generate
 # the file and run this test.
 # Note that this needs to be done for all supported language versions of libc++:
-# for std in c++03 c++11 c++14 c++17 c++20 c++2b; do <build>/bin/llvm-lit --param std=$std ${path_to_this_file}; done
+# for std in c++03 c++11 c++14 c++17 c++20 c++23; do <build>/bin/llvm-lit --param std=$std ${path_to_this_file}; done
 regenerate_expected_results = False
 # Used because the sequence of tokens RUN : can't appear anywhere or it'll confuse Lit.
 RUN = "RUN"

libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.inserters.arithmetic/pointer.volatile.pass.cpp

@@ -13,17 +13,17 @@
 // This test fails in Windows DLL configurations, due to
 // __exclude_from_explicit_instantiation__ not behaving as it should in
 // combination with dllimport (https://llvm.org/PR41018), in combination
-// with running tests in c++2b mode while building the library in c++20 mode.
+// with running tests in c++23 mode while building the library in c++20 mode.
 //
-// If the library was built in c++2b mode, this test would succeed.
+// If the library was built in c++23 mode, this test would succeed.
 //
 // Older CMake passed -std:c++latest to set C++ 20 mode on clang-cl, which
 // hid this issue. With newer CMake versions, it passes -std:c++20 which
 // makes this fail.
 //
 // Marking as UNSUPPORTED instead of XFAIL to avoid spurious failures/successes
 // depending on the version of CMake used.
-// TODO: Remove this when the library is built in c++2b mode.
+// TODO: Remove this when the library is built in c++23 mode.
 //
 // UNSUPPORTED: windows-dll
 

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

@@ -20,7 +20,7 @@
     __cpp_lib_constexpr_algorithms           201806L [C++20]
     __cpp_lib_parallel_algorithm             201603L [C++17]
     __cpp_lib_ranges                         202106L [C++20]
-    __cpp_lib_ranges_starts_ends_with        202106L [C++2b]
+    __cpp_lib_ranges_starts_ends_with        202106L [C++23]
     __cpp_lib_robust_nonmodifying_seq_ops    201304L [C++14]
     __cpp_lib_sample                         201603L [C++17]
     __cpp_lib_shift                          201806L [C++20]
@@ -48,7 +48,7 @@
 # endif
 
 # ifdef __cpp_lib_ranges_starts_ends_with
-#   error "__cpp_lib_ranges_starts_ends_with should not be defined before c++2b"
+#   error "__cpp_lib_ranges_starts_ends_with should not be defined before c++23"
 # endif
 
 # ifdef __cpp_lib_robust_nonmodifying_seq_ops
@@ -82,7 +82,7 @@
 # endif
 
 # ifdef __cpp_lib_ranges_starts_ends_with
-#   error "__cpp_lib_ranges_starts_ends_with should not be defined before c++2b"
+#   error "__cpp_lib_ranges_starts_ends_with should not be defined before c++23"
 # endif
 
 # ifndef __cpp_lib_robust_nonmodifying_seq_ops
@@ -131,7 +131,7 @@
 # endif
 
 # ifdef __cpp_lib_ranges_starts_ends_with
-#   error "__cpp_lib_ranges_starts_ends_with should not be defined before c++2b"
+#   error "__cpp_lib_ranges_starts_ends_with should not be defined before c++23"
 # endif
 
 # ifndef __cpp_lib_robust_nonmodifying_seq_ops
@@ -189,7 +189,7 @@
 # endif
 
 # ifdef __cpp_lib_ranges_starts_ends_with
-#   error "__cpp_lib_ranges_starts_ends_with should not be defined before c++2b"
+#   error "__cpp_lib_ranges_starts_ends_with should not be defined before c++23"
 # endif
 
 # ifndef __cpp_lib_robust_nonmodifying_seq_ops
@@ -216,25 +216,25 @@
 #elif TEST_STD_VER > 20
 
 # ifndef __cpp_lib_clamp
-#   error "__cpp_lib_clamp should be defined in c++2b"
+#   error "__cpp_lib_clamp should be defined in c++23"
 # endif
 # if __cpp_lib_clamp != 201603L
-#   error "__cpp_lib_clamp should have the value 201603L in c++2b"
+#   error "__cpp_lib_clamp should have the value 201603L in c++23"
 # endif
 
 # ifndef __cpp_lib_constexpr_algorithms
-#   error "__cpp_lib_constexpr_algorithms should be defined in c++2b"
+#   error "__cpp_lib_constexpr_algorithms should be defined in c++23"
 # endif
 # if __cpp_lib_constexpr_algorithms != 201806L
-#   error "__cpp_lib_constexpr_algorithms should have the value 201806L in c++2b"
+#   error "__cpp_lib_constexpr_algorithms should have the value 201806L in c++23"
 # endif
 
 # if !defined(_LIBCPP_VERSION)
 #   ifndef __cpp_lib_parallel_algorithm
-#     error "__cpp_lib_parallel_algorithm should be defined in c++2b"
+#     error "__cpp_lib_parallel_algorithm should be defined in c++23"
 #   endif
 #   if __cpp_lib_parallel_algorithm != 201603L
-#     error "__cpp_lib_parallel_algorithm should have the value 201603L in c++2b"
+#     error "__cpp_lib_parallel_algorithm should have the value 201603L in c++23"
 #   endif
 # else // _LIBCPP_VERSION
 #   ifdef __cpp_lib_parallel_algorithm
@@ -243,18 +243,18 @@
 # endif
 
 # ifndef __cpp_lib_ranges
-#   error "__cpp_lib_ranges should be defined in c++2b"
+#   error "__cpp_lib_ranges should be defined in c++23"
 # endif
 # if __cpp_lib_ranges != 202106L
-#   error "__cpp_lib_ranges should have the value 202106L in c++2b"
+#   error "__cpp_lib_ranges should have the value 202106L in c++23"
 # endif
 
 # if !defined(_LIBCPP_VERSION)
 #   ifndef __cpp_lib_ranges_starts_ends_with
-#     error "__cpp_lib_ranges_starts_ends_with should be defined in c++2b"
+#     error "__cpp_lib_ranges_starts_ends_with should be defined in c++23"
 #   endif
 #   if __cpp_lib_ranges_starts_ends_with != 202106L
-#     error "__cpp_lib_ranges_starts_ends_with should have the value 202106L in c++2b"
+#     error "__cpp_lib_ranges_starts_ends_with should have the value 202106L in c++23"
 #   endif
 # else // _LIBCPP_VERSION
 #   ifdef __cpp_lib_ranges_starts_ends_with
@@ -263,24 +263,24 @@
 # endif
 
 # ifndef __cpp_lib_robust_nonmodifying_seq_ops
-#   error "__cpp_lib_robust_nonmodifying_seq_ops should be defined in c++2b"
+#   error "__cpp_lib_robust_nonmodifying_seq_ops should be defined in c++23"
 # endif
 # if __cpp_lib_robust_nonmodifying_seq_ops != 201304L
-#   error "__cpp_lib_robust_nonmodifying_seq_ops should have the value 201304L in c++2b"
+#   error "__cpp_lib_robust_nonmodifying_seq_ops should have the value 201304L in c++23"
 # endif
 
 # ifndef __cpp_lib_sample
-#   error "__cpp_lib_sample should be defined in c++2b"
+#   error "__cpp_lib_sample should be defined in c++23"
 # endif
 # if __cpp_lib_sample != 201603L
-#   error "__cpp_lib_sample should have the value 201603L in c++2b"
+#   error "__cpp_lib_sample should have the value 201603L in c++23"
 # endif
 
 # ifndef __cpp_lib_shift
-#   error "__cpp_lib_shift should be defined in c++2b"
+#   error "__cpp_lib_shift should be defined in c++23"
 # endif
 # if __cpp_lib_shift != 201806L
-#   error "__cpp_lib_shift should have the value 201806L in c++2b"
+#   error "__cpp_lib_shift should have the value 201806L in c++23"
 # endif
 
 #endif // TEST_STD_VER > 20