9.1129 vswprintf

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

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
• This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, IRIX 6.5, Solaris 2.6, Cygwin 1.5.x, Interix 3.5, BeOS.
• On AIX and Windows platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
• On Windows, this function does not take a buffer size as second argument.
• When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.