Merge 2021-10 LWG Motion 17

P2340R1 Clarifying the status of the "C headers"

source/compatibility.tex

@@ -2166,7 +2166,7 @@
 \effect
 A valid ISO C expression utilizing the decrement operator on
 a \tcode{bool} lvalue
-(for instance, via the C typedef in \libdeprheaderref{stdbool.h})
+(for instance, via the C typedef in \libheaderref{stdbool.h})
 is ill-formed in \Cpp{}.
 
 \diffref{expr.sizeof,expr.cast}
@@ -2794,7 +2794,7 @@
 \pnum
 For compatibility with the C standard library\indextext{library!C standard},
 the \Cpp{} standard library provides the C headers enumerated
-in~\ref{depr.c.headers}, but their use is deprecated in \Cpp{}.
+in~\ref{support.c.headers}.
 
 \pnum
 There are no \Cpp{} headers for the C standard library's headers
@@ -2857,15 +2857,15 @@
 \tcode{xor_eq}
 are keywords in \Cpp{}\iref{lex.key},
 and are not introduced as macros
-by \libdeprheaderref{iso646.h}.
+by \libheaderref{iso646.h}.
 
 \rSec3[diff.header.stdalign.h]{Header \tcode{<stdalign.h>}}
 \indexhdr{stdalign.h}%
 
 \pnum
 The token \tcode{alignas} is a keyword in \Cpp{}\iref{lex.key},
 and is not introduced as a macro
-by \libdeprheaderref{stdalign.h}.
+by \libheaderref{stdalign.h}.
 
 \rSec3[diff.header.stdbool.h]{Header \tcode{<stdbool.h>}}
 \indexhdr{stdbool.h}%
@@ -2874,7 +2874,7 @@
 The tokens \tcode{bool}, \tcode{true}, and \tcode{false}
 are keywords in \Cpp{}\iref{lex.key},
 and are not introduced as macros
-by \libdeprheaderref{stdbool.h}.
+by \libheaderref{stdbool.h}.
 
 \rSec3[diff.null]{Macro \tcode{NULL}}
 
@@ -2927,7 +2927,7 @@
 declares the names \tcode{nullptr_t}, \tcode{byte}, and \tcode{to_integer},
 and the operators and operator templates in \iref{support.types.byteops},
 in addition to the names declared in
-\libheaderrefx{stddef.h}{depr.c.headers} in the C standard library.
+\libheaderrefx{stddef.h}{support.c.headers} in the C standard library.
 
 \rSec2[diff.mods.to.behavior]{Modifications to behavior}
 

source/future.tex

@@ -196,191 +196,6 @@
 before the qualified name of a class or alias template
 without a template argument list is deprecated.
 
-\rSec1[depr.c.headers]{C headers}
-
-\rSec2[depr.c.headers.general]{General}
-
-\pnum
-For compatibility with the
-\indextext{library!C standard}%
-C standard library, the \Cpp{} standard library provides
-the \defnx{C headers}{headers!C library} shown in \tref{depr.c.headers}.
-
-\begin{multicolfloattable}{C headers}{depr.c.headers}
-{lllll}
-\libheaderdef{assert.h} \\
-\libheader{complex.h} \\
-\libheaderdef{ctype.h} \\
-\libheaderdef{errno.h} \\
-\libheaderdef{fenv.h} \\
-\libheaderdef{float.h} \\
-\columnbreak
-\libheaderdef{inttypes.h} \\
-\libheader{iso646.h} \\
-\libheaderdef{limits.h} \\
-\libheaderdef{locale.h} \\
-\libheaderdef{math.h} \\
-\libheaderdef{setjmp.h} \\
-\columnbreak
-\libheaderdef{signal.h} \\
-\libheader{stdalign.h} \\
-\libheaderdef{stdarg.h} \\
-\libheader{stdatomic.h} \\
-\libheader{stdbool.h} \\
-\libheaderdef{stddef.h} \\
-\columnbreak
-\libheaderdef{stdint.h} \\
-\libheaderdef{stdio.h} \\
-\libheaderdef{stdlib.h} \\
-\libheaderdef{string.h} \\
-\libheader{tgmath.h} \\
-\libheaderdef{time.h} \\
-\columnbreak
-\libheaderdef{uchar.h} \\
-\libheaderdef{wchar.h} \\
-\libheaderdef{wctype.h} \\
-\end{multicolfloattable}
-
-\rSec2[depr.complex.h.syn]{Header \tcode{<complex.h>} synopsis}
-
-\indexheader{complex.h}%
-\begin{codeblock}
-#include <complex>
-\end{codeblock}
-
-\pnum
-The header \libheader{complex.h}
-behaves as if it simply includes the header
-\libheaderref{complex}.
-
-\pnum
-\begin{note}
-Names introduced by \libheader{complex} in namespace \tcode{std}
-are not placed into the global namespace scope by \libheader{complex.h}.
-\end{note}
-
-\rSec2[depr.iso646.h.syn]{Header \tcode{<iso646.h>} synopsis}
-
-\indexheader{iso646.h}%
-\pnum
-The \Cpp{} header \libheader{iso646.h} is empty.
-\begin{note}
-\tcode{and},
-\tcode{and_eq},
-\tcode{bitand},
-\tcode{bitor},
-\tcode{compl},
-\tcode{not_eq},
-\tcode{not},
-\tcode{or},
-\tcode{or_eq},
-\tcode{xor}, and
-\tcode{xor_eq}
-are keywords in \Cpp{}\iref{lex.key}.
-\end{note}
-
-\rSec2[depr.stdalign.h.syn]{Header \tcode{<stdalign.h>} synopsis}
-
-\indexheader{stdalign.h}%
-\indexlibraryglobal{__alignas_is_defined}%
-\begin{codeblock}
-#define @\xname{alignas_is_defined}@ 1
-\end{codeblock}
-
-\pnum
-The contents of the \Cpp{} header \libheader{stdalign.h} are the same as the C
-standard library header \libheader{stdalign.h}, with the following changes:
-The header \libheader{stdalign.h} does not
-define a macro named \tcode{alignas}.
-
-\xrefc{7.15}
-
-\rSec2[depr.stdbool.h.syn]{Header \tcode{<stdbool.h>} synopsis}
-
-\indexheader{stdbool.h}%
-\indexhdr{stdbool.h}%
-\indexlibraryglobal{__bool_true_false_are_defined}%
-\begin{codeblock}
-#define @\xname{bool_true_false_are_defined}@ 1
-\end{codeblock}
-
-\pnum
-The contents of the \Cpp{} header \libheader{stdbool.h} are the same as the C
-standard library header \libheader{stdbool.h}, with the following changes:
-The header \libheader{stdbool.h} does not
-define macros named \tcode{bool}, \tcode{true}, or \tcode{false}.
-
-\xrefc{7.18}
-
-\rSec2[depr.tgmath.h.syn]{Header \tcode{<tgmath.h>} synopsis}
-
-\indexheader{tgmath.h}%
-\begin{codeblock}
-#include <cmath>
-#include <complex>
-\end{codeblock}
-
-\pnum
-The header \libheader{tgmath.h}
-behaves as if it simply includes the headers
-\libheaderref{cmath} and
-\libheaderref{complex}.
-
-\pnum
-\begin{note}
-The overloads provided in C by type-generic macros
-are already provided in \libheader{complex} and \libheader{cmath}
-by ``sufficient'' additional overloads.
-\end{note}
-
-\pnum
-\begin{note}
-Names introduced by \libheader{cmath} or \libheader{complex}
-in namespace \tcode{std}
-are not placed into the global namespace scope by \libheader{tgmath.h}.
-\end{note}
-
-\rSec2[depr.c.headers.other]{Other C headers}
-
-\pnum
-Every C header
-other than
-\libdeprheaderref{complex.h},
-\libdeprheaderref{iso646.h},
-\libdeprheaderref{stdalign.h},\newline
-\libheaderref{stdatomic.h},
-\libdeprheaderref{stdbool.h}, and
-\libdeprheaderref{tgmath.h},
-each of
-which has a name of the form
-\indextext{header!C}%
-\tcode{<\placeholder{name}.h>},
-behaves as if each name placed in the standard library namespace by
-the corresponding
-\tcode{<c\placeholder{name}>}
-header is placed within
-the global namespace scope,
-except for the functions described in \ref{sf.cmath},
-the declaration of \tcode{std::byte}\iref{cstddef.syn}, and
-the functions and function templates described in \ref{support.types.byteops}.
-It is unspecified whether these names are first declared or defined within
-namespace scope\iref{basic.scope.namespace} of the namespace
-\tcode{std} and are then injected into the global namespace scope by
-explicit \grammarterm{using-declaration}{s}\iref{namespace.udecl}.
-
-\pnum
-\begin{example}
-The header \libheader{cstdlib} assuredly
-provides its declarations and definitions within the namespace
-\tcode{std}. It may also provide these names within the
-global namespace.
-The header \libheader{stdlib.h}
-assuredly provides the same declarations and definitions within
-the global namespace,
-much as in the C Standard. It may also provide these names within
-the namespace \tcode{std}.
-\end{example}
-
 \rSec1[depr.res.on.required]{Requires paragraph}
 
 \pnum

source/lib-intro.tex

@@ -913,7 +913,7 @@
 or namespaces nested within namespace
 \tcode{std}.
 \begin{footnote}
-The C standard library headers\iref{depr.c.headers} also define
+The C standard library headers\iref{support.c.headers} also define
 names within the global namespace, while the \Cpp{} headers for C library
 facilities\iref{headers} can also define names within the global namespace.
 \end{footnote}
@@ -1150,7 +1150,7 @@
 \end{footnote}
 
 \pnum
-\ref{depr.c.headers}, C standard library headers, describes the effects of using
+\ref{support.c.headers}, C standard library headers, describes the effects of using
 the \tcode{\placeholder{name}.h} (C header) form in a \Cpp{} program.
 \begin{footnote}
  The
@@ -1358,7 +1358,7 @@
 \indextext{unit!translation}%
 Each may be included more than once, with no effect different from
 being included exactly once, except that the effect of including either
-\libheaderref{cassert} or \libheaderrefx{assert.h}{depr.c.headers}
+\libheaderref{cassert} or \libheaderrefx{assert.h}{support.c.headers}
 depends each time on the lexically current definition of
 \indextext{\idxcode{NDEBUG}}%
 \indexlibraryglobal{NDEBUG}%
@@ -2898,7 +2898,7 @@
 included after any other header that also defines it\iref{basic.def.odr}.
 
 \pnum
-The C standard library headers\iref{depr.c.headers}
+The C standard library headers\iref{support.c.headers}
 shall include only their corresponding \Cpp{} standard library header,
 as described in~\ref{headers}.