system_data_types.7: Add int_fastN_t family of types

Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
index 4645ed5f488f0cd6bac6aa9d683c08086420da77..c5d0b700d4fd94a7a1f52911fbddb7190a741387 100644 (file)
--- a/man7/system_data_types.7
+++ b/man7/system_data_types.7
@@ -329,6 +329,83 @@ C99 and later; POSIX.1-2001 and later.
 See also:
 .BR imaxdiv (3)
 .RE
+.\"------------------------------------- int_fastN_t ------------------/
+.TP
+.IR int_fast N _t
+.RS
+Include:
+.IR <stdint.h> .
+Alternatively,
+.IR <inttypes.h> .
+.PP
+.IR int_fast8_t ,
+.IR int_fast16_t ,
+.IR int_fast32_t ,
+.I int_fast64_t
+.PP
+Usually the fastest (see Notes) signed integer type
+of a width of at least N bits,
+N being the value specified in its type name.
+According to the C language standard, they shall be
+capable of storing values in the range
+.RB [ INT_FAST N _MIN ,
+.BR INT_FAST N _MAX ],
+substituting N by the appropriate number.
+.PP
+The length modifiers for the
+.IR int_fast N _t
+types for the
+.BR printf (3)
+family of functions
+are expanded by macros of the forms
+.BR PRIdFAST N
+and
+.BR PRIiFAST N
+(defined in
+.IR <inttypes.h> );
+resulting for example in
+.B %"PRIdFAST64"
+or
+.B %"PRIiFAST64"
+for printing
+.I int_fast64_t
+values.
+The length modifiers for the
+.IR int_fast N _t
+types for the
+.BR scanf (3)
+family of functions
+are expanded by macros of the forms
+.BR SCNdFAST N
+and
+.BR SCNiFAST N,
+(defined in
+.IR <inttypes.h> );
+resulting for example in
+.B %"SCNdFAST8"
+or
+.B %"SCNiFAST8"
+for scanning
+.I int_fast8_t
+values.
+.PP
+Conforming to:
+C99 and later; POSIX.1-2001 and later.
+.PP
+Notes:
+Where there is no single type that is fastest for all purposes,
+the implementation may choose any type
+with the required signedness and at least the minimum width.
+.PP
+See also the
+.IR int_least N _t ,
+.IR int N _t ,
+.IR uint_fast N _t ,
+.IR uint_least N _t
+and
+.IR uint N _t
+types in this page.
+.RE
 .\"------------------------------------- intmax_t ---------------------/
 .TP
 .I intmax_t