This function is missing on some platforms:
FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, IRIX 6.5, Solaris 9, Cygwin, Interix 3.5, BeOS.
@item
+This function is only defined as a macro with arguments on some platforms:
+MSVC 9.
+@item
This function is not declared on some platforms:
MacOS X 10.3.
+@item
+This function returns wrong results on some platforms:
+glibc 2.7 on Linux/SPARC64.
@end itemize
Portability problems not fixed by Gnulib: