Merge 2025-06 LWG Motion 3

P3348R4 C++26 should refer to C23 not C17

Author: tkoeppe

source/algorithms.tex

@@ -12006,10 +12006,14 @@
 \indexlibraryglobal{bsearch}%
 \indexlibraryglobal{qsort}%
 \begin{itemdecl}
-void* bsearch(const void* key, const void* base, size_t nmemb, size_t size,
+void* bsearch(const void* key, void* base, size_t nmemb, size_t size,
               @\placeholder{c-compare-pred}@* compar);
-void* bsearch(const void* key, const void* base, size_t nmemb, size_t size,
+void* bsearch(const void* key, void* base, size_t nmemb, size_t size,
               @\placeholder{compare-pred}@* compar);
+const void* bsearch(const void* key, const void* base, size_t nmemb, size_t size,
+                    @\placeholder{c-compare-pred}@* compar);
+const void* bsearch(const void* key, const void* base, size_t nmemb, size_t size,
+                    @\placeholder{compare-pred}@* compar);
 void qsort(void* base, size_t nmemb, size_t size, @\placeholder{c-compare-pred}@* compar);
 void qsort(void* base, size_t nmemb, size_t size, @\placeholder{compare-pred}@* compar);
 \end{itemdecl}
@@ -12029,4 +12033,4 @@
 Any exception thrown by \tcode{compar}\iref{res.on.exception.handling}.
 \end{itemdescr}
 
-\xrefc{7.22.5}
+\xrefc{7.24.5}

source/compatibility.tex

@@ -273,6 +273,18 @@
 \tcode{trivially_relocatable_if_eligible} as macros is invalid
 in this revision of \Cpp{}.
 
+\rSec2[diff.cpp23.mem]{\ref{mem}: memory management library}
+
+\diffref{c.malloc}
+\change
+Calling \tcode{realloc} with a non-null pointer and zero size
+has erroneous behavior.
+\rationale
+The C standard library does not define this behavior.
+\effect
+Valid \CppXXIII{} code that calls \tcode{realloc}
+with a non-null pointer and a size of zero is erroneous and may change behavior.
+
 \rSec2[diff.cpp23.containers]{\ref{containers}: containers library}
 
 \diffref{span.overview}
@@ -3674,12 +3686,12 @@
 
 \rSec2[diff.mods.to.definitions]{Modifications to definitions}
 
-\rSec3[diff.char16]{Types \tcode{char16_t} and \tcode{char32_t}}
+\rSec3[diff.char16]{Types \tcode{char8_t}, \tcode{char16_t}, and \tcode{char32_t}}
 
 \pnum
-The types \keyword{char16_t} and \keyword{char32_t}
+The types \keyword{char8_t}, \keyword{char16_t}, and \keyword{char32_t}
 are distinct types rather than typedefs to existing integral types.
-The tokens \keyword{char16_t} and \keyword{char32_t}
+The tokens \keyword{char8_t}, \keyword{char16_t}, and \keyword{char32_t}
 are keywords in \Cpp{}\iref{lex.key}.
 They do not appear as macro or type names defined in
 \libheaderref{cuchar}.
@@ -3696,14 +3708,6 @@
 \libheaderref{cstdlib},
 or \libheaderref{cwchar}.
 
-\rSec3[diff.header.assert.h]{Header \tcode{<assert.h>}}
-\indexhdr{assert.h}%
-
-\pnum
-The token \keyword{static_assert} is a keyword in \Cpp{}.
-It does not appear as a macro name defined
-in \libheaderref{cassert}.
-
 \rSec3[diff.header.iso646.h]{Header \tcode{<iso646.h>}}
 
 \pnum
@@ -3724,21 +3728,6 @@
 and are not introduced as macros
 by \libheaderref{iso646.h}.
 
-\rSec3[diff.header.stdalign.h]{Header \tcode{<stdalign.h>}}
-
-\pnum
-The token \keyword{alignas} is a keyword in \Cpp{}\iref{lex.key},
-and is not introduced as a macro
-by \libheaderref{stdalign.h}.
-
-\rSec3[diff.header.stdbool.h]{Header \tcode{<stdbool.h>}}
-
-\pnum
-The tokens \keyword{bool}, \keyword{true}, and \keyword{false}
-are keywords in \Cpp{}\iref{lex.key},
-and are not introduced as macros
-by \libheaderref{stdbool.h}.
-
 \rSec3[diff.null]{Macro \tcode{NULL}}
 
 \pnum

source/future.tex

@@ -220,18 +220,33 @@
 \rSec1[depr.c.macros]{Deprecated C macros}
 
 \pnum
-The header \libheaderref{stdalign.h} has the following macros:
+The header \libheaderref{cfloat} has the following macros:
 \begin{codeblock}
-#define @\libxmacro{alignas_is_defined}@ 1
-#define @\libxmacro{alignof_is_defined}@ 1
+#define @\libmacro{FLT_HAS_SUBNORM}@ @\seebelow@
+#define @\libmacro{DBL_HAS_SUBNORM}@ @\seebelow@
+#define @\libmacro{LDBL_HAS_SUBNORM}@ @\seebelow@
+#define @\libmacro{DECIMAL_DIG}@ @\seebelow@
 \end{codeblock}
+The header defines these macros the same as
+the C standard library header \libheader{float.h}.
+
+\xrefc{5.2.4.2.2, 7.33.5}
+
+\pnum
+In addition to being available via inclusion of the \libheader{cfloat} header,
+the macros \tcode{INFINITY} and \tcode{NAN} are
+available when \libheaderref{cmath} is included.
+
+\xrefc{7.12}
 
 \pnum
 The header \libheaderref{stdbool.h} has the following macro:
 \begin{codeblock}
 #define @\libxmacro{bool_true_false_are_defined}@ 1
 \end{codeblock}
 
+\xrefc{7.19}
+
 \rSec1[depr.cerrno]{Deprecated error numbers}
 
 \pnum
@@ -762,6 +777,21 @@
 Equivalent to: \tcode{return visit(std::forward<Visitor>(vis), arg.value);}
 \end{itemdescr}
 
+\rSec1[depr.ctime]{Deprecated time formatting}
+
+\pnum
+The header \libheaderref{ctime} has the following additions:
+\begin{codeblock}
+char* asctime(const tm* timeptr);
+char* ctime(const time_t* timer);
+\end{codeblock}
+
+\pnum
+The functions \tcode{asctime} and \tcode{ctime}
+are not required to avoid data races\iref{res.on.data.races}.
+
+\xrefc{7.29}
+
 \rSec1[depr.fs.path.factory]{Deprecated filesystem path factory functions}
 
 \pnum

source/iostreams.tex

@@ -18875,6 +18875,8 @@
 \indexlibraryglobal{ferror}%
 \indexlibraryglobal{perror}%
 \begin{codeblock}
+#define __STDC_VERSION_STDIO_H__ 202311L
+
 namespace std {
   using size_t = @\textit{see \ref{support.types.layout}}@;
   using FILE = @\seebelow@;
@@ -18889,6 +18891,7 @@
 #define @\libmacro{EOF}@ @\seebelow@
 #define @\libmacro{FOPEN_MAX}@ @\seebelow@
 #define @\libmacro{FILENAME_MAX}@ @\seebelow@
+#define @\libmacro{_PRINTF_NAN_LEN_MAX}@ @\seebelow@
 #define @\libmacro{L_tmpnam}@ @\seebelow@
 #define @\libmacro{SEEK_CUR}@ @\seebelow@
 #define @\libmacro{SEEK_END}@ @\seebelow@
@@ -18983,33 +18986,42 @@
 \indexlibraryglobal{PRIuN}%
 \indexlibraryglobal{PRIxN}%
 \indexlibraryglobal{PRIXN}%
+\indexlibraryglobal{PRIbN}%
+\indexlibraryglobal{PRIBN}%
 \indexlibraryglobal{SCNdN}%
 \indexlibraryglobal{SCNiN}%
 \indexlibraryglobal{SCNoN}%
 \indexlibraryglobal{SCNuN}%
 \indexlibraryglobal{SCNxN}%
+\indexlibraryglobal{SCNbN}%
 \indexlibraryglobal{PRIdLEASTN}%
 \indexlibraryglobal{PRIiLEASTN}%
 \indexlibraryglobal{PRIoLEASTN}%
 \indexlibraryglobal{PRIuLEASTN}%
 \indexlibraryglobal{PRIxLEASTN}%
 \indexlibraryglobal{PRIXLEASTN}%
+\indexlibraryglobal{PRIbLEASTN}%
+\indexlibraryglobal{PRIBLEASTN}%
 \indexlibraryglobal{SCNdLEASTN}%
 \indexlibraryglobal{SCNiLEASTN}%
 \indexlibraryglobal{SCNoLEASTN}%
 \indexlibraryglobal{SCNuLEASTN}%
 \indexlibraryglobal{SCNxLEASTN}%
+\indexlibraryglobal{SCNbLEASTN}%
 \indexlibraryglobal{PRIdFASTN}%
 \indexlibraryglobal{PRIiFASTN}%
 \indexlibraryglobal{PRIoFASTN}%
 \indexlibraryglobal{PRIuFASTN}%
 \indexlibraryglobal{PRIxFASTN}%
 \indexlibraryglobal{PRIXFASTN}%
+\indexlibraryglobal{PRIbFASTN}%
+\indexlibraryglobal{PRIBFASTN}%
 \indexlibraryglobal{SCNdFASTN}%
 \indexlibraryglobal{SCNiFASTN}%
 \indexlibraryglobal{SCNoFASTN}%
 \indexlibraryglobal{SCNuFASTN}%
 \indexlibraryglobal{SCNxFASTN}%
+\indexlibraryglobal{SCNbFASTN}%
 \begin{codeblock}
 #include <cstdint>  // see \ref{cstdint.syn}
 
@@ -19027,61 +19039,78 @@
   constexpr imaxdiv_t div(intmax_t, intmax_t);  // optional, see below
 }
 
+#define __STDC_VERSION_INTTYPES_H__ 202311L
+
 #define PRId@\placeholdernc{N}@ @\seebelow@
 #define PRIi@\placeholdernc{N}@ @\seebelow@
 #define PRIo@\placeholdernc{N}@ @\seebelow@
 #define PRIu@\placeholdernc{N}@ @\seebelow@
 #define PRIx@\placeholdernc{N}@ @\seebelow@
 #define PRIX@\placeholdernc{N}@ @\seebelow@
+#define PRIb@\placeholdernc{N}@ @\seebelow@
+#define PRIB@\placeholdernc{N}@ @\seebelow@
 #define SCNd@\placeholdernc{N}@ @\seebelow@
 #define SCNi@\placeholdernc{N}@ @\seebelow@
 #define SCNo@\placeholdernc{N}@ @\seebelow@
 #define SCNu@\placeholdernc{N}@ @\seebelow@
 #define SCNx@\placeholdernc{N}@ @\seebelow@
+#define SCNb@\placeholdernc{N}@ @\seebelow@
 #define PRIdLEAST@\placeholdernc{N}@ @\seebelow@
 #define PRIiLEAST@\placeholdernc{N}@ @\seebelow@
 #define PRIoLEAST@\placeholdernc{N}@ @\seebelow@
 #define PRIuLEAST@\placeholdernc{N}@ @\seebelow@
 #define PRIxLEAST@\placeholdernc{N}@ @\seebelow@
 #define PRIXLEAST@\placeholdernc{N}@ @\seebelow@
+#define PRIbLEAST@\placeholdernc{N}@ @\seebelow@
+#define PRIBLEAST@\placeholdernc{N}@ @\seebelow@
 #define SCNdLEAST@\placeholdernc{N}@ @\seebelow@
 #define SCNiLEAST@\placeholdernc{N}@ @\seebelow@
 #define SCNoLEAST@\placeholdernc{N}@ @\seebelow@
 #define SCNuLEAST@\placeholdernc{N}@ @\seebelow@
 #define SCNxLEAST@\placeholdernc{N}@ @\seebelow@
+#define SCNbLEAST@\placeholdernc{N}@ @\seebelow@
 #define PRIdFAST@\placeholdernc{N}@ @\seebelow@
 #define PRIiFAST@\placeholdernc{N}@ @\seebelow@
 #define PRIoFAST@\placeholdernc{N}@ @\seebelow@
 #define PRIuFAST@\placeholdernc{N}@ @\seebelow@
 #define PRIxFAST@\placeholdernc{N}@ @\seebelow@
 #define PRIXFAST@\placeholdernc{N}@ @\seebelow@
+#define PRIbFAST@\placeholdernc{N}@ @\seebelow@
+#define PRIBFAST@\placeholdernc{N}@ @\seebelow@
 #define SCNdFAST@\placeholdernc{N}@ @\seebelow@
 #define SCNiFAST@\placeholdernc{N}@ @\seebelow@
 #define SCNoFAST@\placeholdernc{N}@ @\seebelow@
 #define SCNuFAST@\placeholdernc{N}@ @\seebelow@
 #define SCNxFAST@\placeholdernc{N}@ @\seebelow@
+#define SCNbFAST@\placeholdernc{N}@ @\seebelow@
 #define @\libmacro{PRIdMAX}@ @\seebelow@
 #define @\libmacro{PRIiMAX}@ @\seebelow@
 #define @\libmacro{PRIoMAX}@ @\seebelow@
 #define @\libmacro{PRIuMAX}@ @\seebelow@
 #define @\libmacro{PRIxMAX}@ @\seebelow@
 #define @\libmacro{PRIXMAX}@ @\seebelow@
+#define @\libmacro{PRIbMAX}@ @\seebelow@
+#define @\libmacro{PRIBMAX}@ @\seebelow@
 #define @\libmacro{SCNdMAX}@ @\seebelow@
 #define @\libmacro{SCNiMAX}@ @\seebelow@
 #define @\libmacro{SCNoMAX}@ @\seebelow@
 #define @\libmacro{SCNuMAX}@ @\seebelow@
 #define @\libmacro{SCNxMAX}@ @\seebelow@
+#define @\libmacro{SCNbMAX}@ @\seebelow@
 #define @\libmacro{PRIdPTR}@ @\seebelow@
 #define @\libmacro{PRIiPTR}@ @\seebelow@
 #define @\libmacro{PRIoPTR}@ @\seebelow@
 #define @\libmacro{PRIuPTR}@ @\seebelow@
 #define @\libmacro{PRIxPTR}@ @\seebelow@
 #define @\libmacro{PRIXPTR}@ @\seebelow@
+#define @\libmacro{PRIbPTR}@ @\seebelow@
+#define @\libmacro{PRIBPTR}@ @\seebelow@
 #define @\libmacro{SCNdPTR}@ @\seebelow@
 #define @\libmacro{SCNiPTR}@ @\seebelow@
 #define @\libmacro{SCNoPTR}@ @\seebelow@
 #define @\libmacro{SCNuPTR}@ @\seebelow@
 #define @\libmacro{SCNxPTR}@ @\seebelow@
+#define @\libmacro{SCNbPTR}@ @\seebelow@
 \end{codeblock}
 
 \pnum
@@ -19093,10 +19122,6 @@
 The header \libheader{cinttypes} includes the header \libheaderref{cstdint} instead
 of \libheader{stdint.h}, and
 \item
-\tcode{intmax_t} and \tcode{uintmax_t} are not required
-to be able to represent all values of extended integer types
-wider than \tcode{long long} and \tcode{unsigned long long}, respectively, and
-\item
 if and only if the type \tcode{intmax_t} designates an extended integer
 type\iref{basic.fundamental}, the following function signatures are added:
 \begin{codeblock}
@@ -19118,3 +19143,6 @@
 is defined if and only if the implementation
 defines the corresponding \grammarterm{typedef-name} in~\ref{cstdint.syn} and
 has a suitable \tcode{fscanf} length modifier for the type.
+Each of the \tcode{PRIB} macros listed in this subclause
+is defined if and only if \tcode{fprintf} supports
+the \tcode{B} conversion specifier.

source/macros.tex

@@ -292,7 +292,7 @@
 \newcommand{\CppXXIII}{\Cpp{} 2023}
 \newcommand{\CppXXVI}{\Cpp{} 2026}
 \newcommand{\IsoCUndated}{ISO/IEC 9899}
-\newcommand{\IsoC}{\IsoCUndated{}:2018}
+\newcommand{\IsoC}{\IsoCUndated{}:2024}
 \newcommand{\IsoFloatUndated}{ISO/IEC 60559}
 \newcommand{\IsoPosixUndated}{ISO/IEC/IEEE 9945}
 \newcommand{\IsoPosix}{\IsoPosixUndated{}:2009}

source/memory.tex

@@ -2022,12 +2022,10 @@
 \indexlibraryglobal{aligned_alloc}%
 \indexlibraryglobal{calloc}%
 \indexlibraryglobal{malloc}%
-\indexlibraryglobal{realloc}%
 \begin{itemdecl}
 void* aligned_alloc(size_t alignment, size_t size);
 void* calloc(size_t nmemb, size_t size);
 void* malloc(size_t size);
-void* realloc(void* ptr, size_t size);
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -2045,8 +2043,35 @@
 These functions implicitly create objects\iref{intro.object}
 in the returned region of storage and
 return a pointer to a suitable created object.
-In the case of \tcode{calloc} and \tcode{realloc},
-the objects are created before the storage is zeroed or copied, respectively.
+In the case of \tcode{calloc},
+the objects are created before the storage is zeroed.
+\end{itemdescr}
+
+\indexlibraryglobal{realloc}%
+\begin{itemdecl}
+void* realloc(void* ptr, size_t size);
+\end{itemdecl}
+
+\begin{itemdescr}
+\pnum
+\expects
+\tcode{free(ptr)} has well-defined behavior.
+
+\pnum
+\effects
+If \tcode{ptr} is not null and \tcode{size} is zero,
+the behavior is erroneous and the effects are implementation-defined.
+Otherwise, this function has the semantics specified in the C standard library.
+
+\pnum
+\remarks
+This function does not attempt to allocate storage
+by calling \tcode{::operator new()}\iref{new.delete}.
+When a non-null pointer is returned,
+this function implicitly creates objects\iref{intro.object}
+in the returned region of storage and
+returns a pointer to a suitable created object.
+The objects are created before the storage is copied.
 \end{itemdescr}
 
 \indexlibraryglobal{free}%