9.58 btowc

POSIX specification:
http://www.opengroup.org/onlinepubs/9699919799/functions/btowc.html

Gnulib module: btowc

Portability problems fixed by Gnulib:

• This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, IRIX 5.3, Solaris 2.6, mingw, Interix 3.5.
• This function returns WEOF for a NUL argument on some platforms: Cygwin 1.7.2.
• This function does not return WEOF for an EOF argument on some platforms: IRIX 6.5.

Portability problems not fixed by Gnulib:

• On AIX and Windows platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.