@node btowc
@subsection @code{btowc}
@findex btowc

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/functions/btowc.html}

Gnulib module: btowc
@mindex btowc

Portability problems fixed by Gnulib:
@itemize
@item
This function is missing on some platforms:
Minix 3.1.8, HP-UX 11.00, mingw.
@item
This function returns WEOF for a NUL argument on some platforms:
Cygwin 1.7.2.
@item
In the C or POSIX locales, this function is not consistent with
Gnulib's @code{mbrtowc} and can return @code{WEOF}:
glibc 2.35, MirOS BSD #10.
@item
In the C or POSIX locales, this function is not consistent with @code{mbrtowc}
on some platforms:
Cygwin 3.4.x, mingw with MSVCRT.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
On Windows and 32-bit AIX platforms, @code{wchar_t} is a 16-bit type and
therefore cannot accommodate all Unicode characters.
@mindex btoc32
However, the Gnulib function @code{btoc32}, provided by Gnulib module
@code{btoc32}, operates on 32-bit wide characters and therefore does not have
this limitation.
@end itemize
