9.572 modf

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

Gnulib module: modf or modf-ieee

Portability problems fixed by either Gnulib module modf or modf-ieee:

Portability problems fixed by Gnulib module modf-ieee:

• This function has problems with a NaN argument on some platforms: NetBSD 5.1, Cygwin.
• This function has problems with infinite arguments on some platforms: FreeBSD 6.4, OpenBSD 4.9, IRIX 6.5, OSF/1 5.1.

Portability problems not fixed by Gnulib: