FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, HP-UX 11, IRIX 6.5, Solaris 9, Cygwin, Interix 3.5.
@item
This function does not work on finite numbers on some platforms:
-AIX 5.1.
+AIX 5.1, BeOS.
@item
This function does not work on infinite numbers on some platforms:
IRIX 6.5.