Template:cpp/thread/wait until clock note

The standard recommends that the clock tied to be used to measure time; that clock is not required to be a monotonic clock. There are no guarantees regarding the behavior of this function if the clock is adjusted discontinuously, but the existing implementations convert from  to std and delegate to POSIX  so that the wait honors adjustments to the system clock, but not to the user-provided. In any case, the function also may wait for longer than until after has been reached due to scheduling or resource contention delays.