concept wait_for() in category c++

This is an excerpt from Manning's book C++ Concurrency in Action, Second Edition. Login to get full access to this book.

So, for example, std::condition_variable has two overloads of the wait_for() member function and two overloads of the wait_until() member function that correspond to the two overloads of wait()—one overload that just waits until signaled, or the timeout expires, or a spurious wakeup occurs; and another that will check the supplied predicate when woken and will return only when the supplied predicate is true (and the condition variable has been signaled) or the timeout expires.

Preconditions There are no threads blocked on *this in a call to wait(), wait_for(), or wait_until().