Add C++23 header macros.

include/boost/config/assert_cxx03.hpp

@@ -1,4 +1,4 @@
-//  This file was automatically generated on Sun Jun  5 16:50:18 2022
+//  This file was automatically generated on Sat Sep  9 19:03:28 2023
 //  by libs/config/tools/generate.cpp
 //  Copyright John Maddock 2002-21.
 //  Use, modification and distribution are subject to the 

include/boost/config/assert_cxx11.hpp

@@ -1,4 +1,4 @@
-//  This file was automatically generated on Sun Jun  5 16:50:18 2022
+//  This file was automatically generated on Sat Sep  9 19:03:28 2023
 //  by libs/config/tools/generate.cpp
 //  Copyright John Maddock 2002-21.
 //  Use, modification and distribution are subject to the 
@@ -18,6 +18,9 @@
 #ifdef BOOST_NO_CXX11_ALIGNAS
 #  error "Your compiler appears not to be fully C++11 compliant.  Detected via defect macro BOOST_NO_CXX11_ALIGNAS."
 #endif
+#ifdef BOOST_NO_CXX11_ALIGNOF
+#  error "Your compiler appears not to be fully C++11 compliant.  Detected via defect macro BOOST_NO_CXX11_ALIGNOF."
+#endif
 #ifdef BOOST_NO_CXX11_ALLOCATOR
 #  error "Your compiler appears not to be fully C++11 compliant.  Detected via defect macro BOOST_NO_CXX11_ALLOCATOR."
 #endif

include/boost/config/assert_cxx14.hpp

@@ -1,4 +1,4 @@
-//  This file was automatically generated on Sun Jun  5 16:50:18 2022
+//  This file was automatically generated on Sat Sep  9 19:03:28 2023
 //  by libs/config/tools/generate.cpp
 //  Copyright John Maddock 2002-21.
 //  Use, modification and distribution are subject to the 

include/boost/config/assert_cxx17.hpp

@@ -1,4 +1,4 @@
-//  This file was automatically generated on Sun Jun  5 16:50:18 2022
+//  This file was automatically generated on Sat Sep  9 19:03:28 2023
 //  by libs/config/tools/generate.cpp
 //  Copyright John Maddock 2002-21.
 //  Use, modification and distribution are subject to the 

include/boost/config/assert_cxx20.hpp

@@ -1,4 +1,4 @@
-//  This file was automatically generated on Sun Jun  5 16:50:18 2022
+//  This file was automatically generated on Sat Sep  9 19:03:28 2023
 //  by libs/config/tools/generate.cpp
 //  Copyright John Maddock 2002-21.
 //  Use, modification and distribution are subject to the 

include/boost/config/detail/cxx_composite.hpp

@@ -1,4 +1,4 @@
-//  This file was automatically generated on Sun Jun  5 16:50:18 2022
+//  This file was automatically generated on Sat Sep  9 19:03:28 2023
 //  by libs/config/tools/generate.cpp
 //  Copyright John Maddock 2002-21.
 //  Use, modification and distribution are subject to the 
@@ -81,6 +81,7 @@
 #if defined(BOOST_NO_CXX03)\
    || defined(BOOST_NO_CXX11_ADDRESSOF)\
    || defined(BOOST_NO_CXX11_ALIGNAS)\
+   || defined(BOOST_NO_CXX11_ALIGNOF)\
    || defined(BOOST_NO_CXX11_ALLOCATOR)\
    || defined(BOOST_NO_CXX11_AUTO_DECLARATIONS)\
    || defined(BOOST_NO_CXX11_AUTO_MULTIDECLARATIONS)\
@@ -201,3 +202,16 @@
 #    define BOOST_NO_CXX20
 #endif
 
+#if defined(BOOST_NO_CXX20)\
+   || defined(BOOST_NO_CXX23_HDR_EXPECTED)\
+   || defined(BOOST_NO_CXX23_HDR_FLAT_MAP)\
+   || defined(BOOST_NO_CXX23_HDR_FLAT_SET)\
+   || defined(BOOST_NO_CXX23_HDR_GENERATOR)\
+   || defined(BOOST_NO_CXX23_HDR_MDSPAN)\
+   || defined(BOOST_NO_CXX23_HDR_PRINT)\
+   || defined(BOOST_NO_CXX23_HDR_SPANSTREAM)\
+   || defined(BOOST_NO_CXX23_HDR_STACKTRACE)\
+   || defined(BOOST_NO_CXX23_HDR_STDFLOAT)
+#    define BOOST_NO_CXX23
+#endif
+

include/boost/config/detail/suffix.hpp

@@ -1257,6 +1257,46 @@ namespace std{ using ::type_info; }
 #endif
 #endif
 
+#if (!defined(__has_include) || (BOOST_CXX_VERSION < 202003L))
+#  define BOOST_NO_CXX23_HDR_EXPECTED
+#  define BOOST_NO_CXX23_HDR_FLAT_MAP
+#  define BOOST_NO_CXX23_HDR_FLAT_SET
+#  define BOOST_NO_CXX23_HDR_GENERATOR
+#  define BOOST_NO_CXX23_HDR_MDSPAN
+#  define BOOST_NO_CXX23_HDR_PRINT
+#  define BOOST_NO_CXX23_HDR_SPANSTREAM
+#  define BOOST_NO_CXX23_HDR_STACKTRACE
+#  define BOOST_NO_CXX23_HDR_STDFLOAT
+#else
+#if (!__has_include(<expected>) || !defined(__cpp_lib_expected) || (__cpp_lib_expected < 202211L)) && !defined(BOOST_NO_CXX23_HDR_EXPECTED)
+#  define BOOST_NO_CXX23_HDR_EXPECTED
+#endif
+#if (!__has_include(<flat_map>) || !defined(__cpp_lib_flat_map) || (__cpp_lib_flat_map < 202207L)) && !defined(BOOST_NO_CXX23_HDR_FLAT_MAP)
+#  define BOOST_NO_CXX23_HDR_FLAT_MAP
+#endif
+#if (!__has_include(<flat_set>) || !defined(__cpp_lib_flat_set) || (__cpp_lib_flat_set < 202207L)) && !defined(BOOST_NO_CXX23_HDR_FLAT_SET)
+#  define BOOST_NO_CXX23_HDR_FLAT_SET
+#endif
+#if (!__has_include(<generator>) || !defined(__cpp_lib_generator) || (__cpp_lib_generator < 202207L)) && !defined(BOOST_NO_CXX23_HDR_GENERATOR)
+#  define BOOST_NO_CXX23_HDR_GENERATOR
+#endif
+#if (!__has_include(<mdspan>) || !defined(__cpp_lib_mdspan) || (__cpp_lib_mdspan < 202207L)) && !defined(BOOST_NO_CXX23_HDR_MDSPAN)
+#  define BOOST_NO_CXX23_HDR_MDSPAN
+#endif
+#if (!__has_include(<print>) || !defined(__cpp_lib_print) || (__cpp_lib_print < 202207L)) && !defined(BOOST_NO_CXX23_HDR_PRINT)
+#  define BOOST_NO_CXX23_HDR_PRINT
+#endif
+#if (!__has_include(<spanstream>) || !defined(__cpp_lib_spanstream) || (__cpp_lib_spanstream < 202106L)) && !defined(BOOST_NO_CXX23_HDR_SPANSTREAM)
+#  define BOOST_NO_CXX23_HDR_SPANSTREAM
+#endif
+#if (!__has_include(<stacktrace>) || !defined(__cpp_lib_stacktrace) || (__cpp_lib_stacktrace < 202011L)) && !defined(BOOST_NO_CXX23_HDR_STACKTRACE)
+#  define BOOST_NO_CXX23_HDR_STACKTRACE
+#endif
+#if !__has_include(<stdfloat>) && !defined(BOOST_NO_CXX23_HDR_STDFLOAT)
+#  define BOOST_NO_CXX23_HDR_STDFLOAT
+#endif
+#endif
+
 #if defined(__cplusplus) && defined(__has_include)
 #if !__has_include(<version>)
 #  define BOOST_NO_CXX20_HDR_VERSION