@item
This function is missing on some platforms:
NetBSD 3.0, OpenBSD 3.8, HP-UX 11.00, IRIX 6.5, Solaris 2.6, Interix
-3.5, BeOS, Cygwin 1.7.
+3.5, BeOS.
@item
This function exists, but does not support wide arguments on some
platforms: Cygwin 1.5.x.