5 POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/btowc.html}
9 Portability problems fixed by Gnulib:
12 This function is missing on some platforms:
13 HP-UX 11.00, IRIX 5.3, Solaris 2.6, mingw, Interix 3.5.
16 Portability problems not fixed by Gnulib:
19 On AIX and Windows platforms, @code{wchar_t} is a 16-bit type and therefore cannot
20 accommodate all Unicode characters.