Add wording for new <simd> header and [simd] subclause

Plus a few formatting adjustments.

ChangeLog:

	* P1928/changelog.tex:
	* P1928/main.tex:
	* P1928/wording.tex:
	* wg21macros.sty:

P1928/changelog.tex

@@ -136,6 +136,7 @@ \section{Changelog}
 \item Spell out “iff” (\ref{wording.deducet}).
 \item Fixed template argument to \nativeabi\ in the default template argument of \code{basic_simd_mask} (\ref{sec:simd.syn}).
 \item Fixed default template argument to \code{simd_mask} to be consistent with \code{simd} (\ref{sec:simd.syn}).
-
-  \todo Add \code{<simd>} to the list of headers in 16.4.2.3
+\item Add instructions to add \code{<simd>} to the table of headers in [headers].
+\item Add instructions to add a new subclause to the table in [numerics.general].
+\item Add instructions to add \code{<simd>} [diff.23.library].
 \end{revision}

P1928/main.tex

@@ -189,7 +189,7 @@ \subsection{Simplify/generalize casts}\label{sec:casts}
 \subsection{Add \code{simd_mask} generator constructor}
 
 This constructor was added:
-\begin{wgText}
+\begin{wgText}\vskip-2ex
 \begin{itemdecl}
 template<class G> simd_mask(G&& gen) noexcept;
 \end{itemdecl}
@@ -915,16 +915,45 @@ \section{Wording: Add Section 9 of N4808 with modifications}\label{sec:wording}
 The following section presents the wording to be applied against the \CC{}
 working draft.
 
-\begin{wgText}[In {[version.syn]}, add]
-  \begin{codeblock}
-    #define __cpp_lib_simd YYYYMML // also in <simd>
-  \end{codeblock}
+\bigskip
+In {[headers]}, add the header {\wgTextFonts\wgAdd{\code{<simd>}}} to
+{[tab:headers.cpp]}.
+
+\bigskip
+In {[numerics.general]}, add a new row to {[tab:numerics.summary]}:\\
+\begingroup
+  \rmfamily\smaller[1]
+  \begin{tabular}{|lll|}
+    \hline
+    \wgAdd{[simd]} & \wgAdd{Data-parallel types} & \wgAdd{\code{<simd>}} \\
+    \hline
+  \end{tabular}
+\endgroup
+\par\vskip.5\baselineskip plus 2\baselineskip
+
+\bigskip
+In {[diff.23.library]}, modify:
+\begin{wgText}[{[diff.23.library]}]
+  \pnum
+  \textbf{Affected subclause:} [headers]
+  \diffdef{Change} New headers.
+  \diffdef{Rationale} New functionality.
+  \diffdef{Effect on original feature} The following \CC{} headers are new: \tcode{<debugging>},
+  \tcode{<hazard_pointer>}, \tcode{<linalg>}, \tcode{<rcu>},\wgAdd{ \tcode{<simd>,}} and \tcode{<text_encoding>}.
+    Valid \CC{} 2023 code that \tcode{\#include}{s} headers with these names may be invalid in this revision of \CC{}.
 \end{wgText}
-Adjust the placeholder value as needed so as to denote this proposal's date of adoption.
+\bigskip
 
-\begin{wgText}[Add a new subclause after §28.8 {[numbers]}]
+In {[version.syn]}, add the following and adjust the placeholder value as
+needed so as to denote this proposal's date of adoption:
+\begin{wgText}[{[version.syn]}]
+  \wgAdd{\tcode{\#define __cpp_lib_simd YYYYMML // also in <simd>}}
+\end{wgText}
+
+Add a new subclause after §28.9 {[linalg]}:
+\begin{wgText}
   \setcounter{WGClause}{28}
-  \setcounter{WGSubSection}{8}
+  \setcounter{WGSubSection}{9}
   \lstset{%
     columns=fullflexible,
     deletedelim=**[is]{|-}{-|},

P1928/wording.tex

@@ -30,7 +30,7 @@
 \constraints Application of #1 to objects of type \tcode{value_type} is well-formed.
 }
 
-\rSec0[simd]{Data-Parallel Types}
+\rSec0[simd]{Data-parallel types}
 \rSec1[simd.general]{General}
 
 \pnum

wg21macros.sty

@@ -77,8 +77,10 @@
 \newcommand\wgItemRem{\color{WgRem}\item[\st{\mbox{ \textbullet }}]\hspace*{-\labelsep}\st{\mbox{\hspace*{\labelsep}}}}
 \newenvironment{wgBAdd}{\color{WgAdd}}{\color{black}}
 \newenvironment{wgBRem}{\color{WgRem}}{\color{black}}
+\newcommand\wgTextFonts{\def\ttdefault{wgCodeFont}\rmfamily\smaller[1]}
 \def\wgLabelPrefix{}%
 \newenvironment{wgText}[1][]{%
+  \vskip.2\baselineskip plus 1\baselineskip
   \begingroup%
   \let\wgRealRef=\ref%
   \renewcommand\ref[1]{\wgRealRef{sec:\wgLabelPrefix##1}}%
@@ -102,20 +104,20 @@
     moredelim=**[is][\itshape]{|/}{/|}
   }%
   \let\type=\code%
-  \def\ttdefault{wgCodeFont}%
-  \par\rmfamily\smaller[1]\noindent\hrulefill%
+  \wgTextFonts%
+  \par\noindent\hrulefill%
   \begingroup%
     \def\arg{#1}%
     \def\empty{}%
     \ifx\arg\empty\else%
       \hspace{1ex} #1%
     \fi%
-  \endgroup\par
+  \endgroup\par\nopagebreak[4]\vskip.2\baselineskip%
 }
 {%
-  \par\noindent\hrulefill%
+  \par\nopagebreak[4]\vskip-.3\baselineskip\nopagebreak[4]\noindent\hrulefill%
   \endgroup\par%
-  \vskip.5\baselineskip plus 2\baselineskip%
+  \vskip.9\baselineskip plus 4\baselineskip\pagebreak[1]%
 }
 
 %%--------------------------------------------------
@@ -412,3 +414,7 @@
 
 \newcommand{\UNSP}[1]{\textit{\texttt{#1}}}
 \newcommand{\seebelow}{\UNSP{see below}}
+
+%% Change descriptions
+\newcommand{\diffhead}[1]{\textbf{#1:}\space}
+\newcommand{\diffdef}[1]{\ifvmode\else\hfill\break\fi\diffhead{#1}}