9.1183 wcwidth

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

Gnulib module: wcwidth

Portability problems fixed by Gnulib:

• This function is missing on some platforms: Minix 3.1.8, IRIX 5.3, Solaris 2.5.1, mingw, MSVC 9, BeOS.
• This function is not declared (without -D_GNU_SOURCE) on some platforms: glibc 2.8.
• This function handles combining characters in UTF-8 locales incorrectly on some platforms: Mac OS X 10.3, OpenBSD 5.8.

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.