@@ -2990,23 +2990,45 @@ double} is a separate type).
These functions have been GNU extensions and are new to @w{ISO C99}.
@end deftypefun
+@comment stdlib.h
+@comment ISO/IEC TS 18661-3
+@deftypefun _Float@var{N} strtof@var{N} (const char *@var{string}, char **@var{tailptr})
+@deftypefunx _Float@var{N}x strtof@var{N}x (const char *@var{string}, char **@var{tailptr})
+@safety{@prelim{}@mtsafe{@mtslocale{}}@assafe{}@acsafe{}}
+These functions are like @code{strtod}, except for the return type.
+
+They were introduced in @w{ISO/IEC TS 18661-3} and are available on machines
+that support the related types, as described in @ref{Mathematics}.
+@end deftypefun
+
@comment wchar.h
@comment ISO
@deftypefun double wcstod (const wchar_t *restrict @var{string}, wchar_t **restrict @var{tailptr})
-@comment stdlib.h
+@comment wchar.h
@comment ISO
@deftypefunx float wcstof (const wchar_t *@var{string}, wchar_t **@var{tailptr})
-@comment stdlib.h
+@comment wchar.h
@comment ISO
@deftypefunx {long double} wcstold (const wchar_t *@var{string}, wchar_t **@var{tailptr})
+@comment wchar.h
+@deftypefunx _Float@var{N} wcstof@var{N} (const wchar_t *@var{string}, wchar_t **@var{tailptr})
+@deftypefunx _Float@var{N}x wcstof@var{N}x (const wchar_t *@var{string}, wchar_t **@var{tailptr})
@safety{@prelim{}@mtsafe{@mtslocale{}}@assafe{}@acsafe{}}
-The @code{wcstod}, @code{wcstof}, and @code{wcstol} functions are
-equivalent in nearly all aspect to the @code{strtod}, @code{strtof}, and
-@code{strtold} functions but it handles wide character string.
+The @code{wcstod}, @code{wcstof}, @code{wcstol}, @code{wcstof}@var{N},
+and @code{wcstof}@var{N}@code{x} functions are equivalent in nearly all
+aspect to the @code{strtod}, @code{strtof}, @code{strtold},
+@code{strtof}@var{N}, and @code{strtof}@var{N}@code{x} functions but
+they handle wide character string.
The @code{wcstod} function was introduced in @w{Amendment 1} of @w{ISO
C90}. The @code{wcstof} and @code{wcstold} functions were introduced in
@w{ISO C99}.
+
+The @code{wcstof}@var{N} and @code{wcstof}@var{N}@code{x} functions are
+not in any standard, but are added to provide completeness for the
+non-deprecated interface of wide character string to floating-point
+conversion function. They are only available on machines that support
+the related types as described in @ref{Mathematics}.
@end deftypefun
@comment stdlib.h
@@ -3064,6 +3086,19 @@ has been completely written if and only if the returned value is less than
These functions were introduced by ISO/IEC TS 18661-1.
@end deftypefun
+@comment stdlib.h
+@comment ISO/IEC TS 18661-3
+@deftypefun int strfromf@var{N} (char *restrict @var{string}, size_t @var{size}, const char *restrict @var{format}, _Float@var{N} @var{value})
+@deftypefunx int strfromf@var{N}x (char *restrict @var{string}, size_t @var{size}, const char *restrict @var{format}, _Float@var{N}x @var{value})
+@safety{@prelim{}@mtsafe{@mtslocale{}}@asunsafe{@ascuheap{}}@acunsafe{@acsmem{}}}
+@comment this function depends on __printf_fp and __printf_fphex, which are
+@comment AS-unsafe (ascuheap) and AC-unsafe (acsmem).
+These functions are like @code{strfromd}, except for the type of @var{value}.
+
+They were introduced in @w{ISO/IEC TS 18661-3} and are available on machines
+that support the related types, as described in @ref{Mathematics}.
+@end deftypefun
+
@node System V Number Conversion
@section Old-fashioned System V number-to-string functions
@@ -53,6 +53,17 @@ usually wise to pick the narrowest type that can accommodate your data.
Not all machines have a distinct @code{long double} type; it may be the
same as @code{double}.
+On some machines, @theglibc{} also provides @code{_Float}@var{N} and
+@code{_Float}@var{N}@code{x} types. These types are defined in
+@w{ISO/IEC 18661-3}, which extends @w{ISO C} and defines floating-point
+types tha are not machine-dependent. When such a type, e.g.
+@code{_Float128}, is supported by @theglibc{}, extra variants for most
+of the mathematical functions provided for @code{double}, @code{float},
+and @code{lond double} are also provided for the supported type.
+
+Currently, support for @code{_Float}@var{N} or
+@code{_Float}@var{N}@code{x} types is not provided for any machine.
+
@menu
* Mathematical Constants:: Precise numeric values for often-used
constants.