@node mbstowcs @section @code{mbstowcs} @findex mbstowcs POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbstowcs.html} Gnulib module: mbstowcs Portability problems fixed by Gnulib: @itemize @item In the C or POSIX locales, this function can return @code{(size_t) -1} and set @code{errno} to @code{EILSEQ}: glibc 2.35. @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. However, the Gnulib function @code{mbstoc32s}, provided by Gnulib module @code{mbstoc32s}, operates on 32-bit wide characters and therefore does not have this limitation. @end itemize