P2909R4 Fix formatting of code units as integers (Dude, where’s my char?)

Author: burblebee

source/support.tex

@@ -634,6 +634,7 @@
 #define @\defnlibxname{cpp_lib_flat_set}@                          202207L // also in \libheader{flat_set}
 #define @\defnlibxname{cpp_lib_format}@                            202311L // also in \libheader{format}
 #define @\defnlibxname{cpp_lib_format_ranges}@                     202207L // also in \libheader{format}
+#define @\defnlibxname{cpp_lib_format_uchar}@                      202311L // also in \libheader{format}
 #define @\defnlibxname{cpp_lib_formatters}@                        202302L // also in \libheader{stacktrace}, \libheader{thread}
 #define @\defnlibxname{cpp_lib_forward_like}@                      202207L // freestanding, also in \libheader{utility}
 #define @\defnlibxname{cpp_lib_freestanding_algorithm}@            202311L

source/utilities.tex

@@ -16331,15 +16331,16 @@
 \pnum
 The available \tcode{charT} presentation types are specified in \tref{format.type.char}.
 %
-\begin{floattable}{Meaning of \fmtgrammarterm{type} options for \tcode{charT}}{format.type.char}{ll}
+\begin{floattable}{Meaning of \fmtgrammarterm{type} options for \tcode{charT}}{format.type.char}{lp{.8\hsize}}
 \topline
 \lhdr{Type} & \rhdr{Meaning} \\ \rowsep
 none, \tcode{c} &
 Copies the character to the output.
 \\ \rowsep
 %
 \tcode{b}, \tcode{B}, \tcode{d}, \tcode{o}, \tcode{x}, \tcode{X} &
-As specified in \tref{format.type.int}.
+As specified in \tref{format.type.int}
+with \tcode{value} converted to the unsigned version of the underlying type.
 \\ \rowsep
 %
 \tcode{?} &
@@ -18262,7 +18263,7 @@
 \item
 otherwise, if \tcode{TD} is \tcode{char} and \tcode{char_type} is
 \keyword{wchar_t}, initializes \tcode{value} with
-\tcode{static_cast<wchar_t>(v)};
+\tcode{static_cast<wchar_t>(static_cast<unsigned char>(v))};
 \item
 otherwise, if \tcode{TD} is a signed integer type\iref{basic.fundamental}
 and \tcode{sizeof(TD) <= sizeof(int)},