4 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/basedefs/time.h.html}
8 Portability problems fixed by Gnulib:
11 @samp{struct timespec} is not defined on some platforms.
14 Some platforms provide a @code{NULL} macro that cannot be used in arbitrary
19 Portability problems not fixed by Gnulib:
22 On some platforms the @code{tv_nsec} member of @code{struct timespec}
23 is not of type @code{long}, but is of type @code{long long} instead: