[Bug libstdc++/54847] --enable-libstdcxx-time=yes non-functional on darwin

["howarth at nitro dot med.uc.edu" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54847

--- Comment #5 from Jack Howarth <howarth at nitro dot med.uc.edu> 2012-10-07 18:50:09 UTC ---
As far as I can see the only usage of nanosleep() in libstdc++-v3 is in this
section of the include/std/thread header...

#ifdef _GLIBCXX_USE_NANOSLEEP
    /// sleep_for
    template<typename _Rep, typename _Period>
      inline void
      sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
      {
        chrono::seconds __s =
          chrono::duration_cast<chrono::seconds>(__rtime);

        chrono::nanoseconds __ns =
          chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);

        __gthread_time_t __ts =
          {
            static_cast<std::time_t>(__s.count()),
            static_cast<long>(__ns.count())
          };

        ::nanosleep(&__ts, 0);
      }

    /// sleep_until
    template<typename _Clock, typename _Duration>
      inline void
      sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
      { sleep_for(__atime - _Clock::now()); }
#endif