Function gnunet_sys::GNUNET_TIME_absolute_get_remaining

pub unsafe extern "C" fn GNUNET_TIME_absolute_get_remaining(
    future: GNUNET_TIME_Absolute
) -> GNUNET_TIME_Relative

Given a timestamp in the future, how much time remains until then?

@param future some absolute time, typically in the future @return future - now, or 0 if now >= future, or FOREVER if future==FOREVER.