30 Thread support library [thread]

30.3 Threads [thread.threads]

30.3.1 Class thread [thread.thread.class] thread assignment [thread.thread.assign]

thread& operator=(thread&& x) noexcept;

Effects: If joinable(), calls std::terminate(). Otherwise, assigns the state of x to *this and sets x to a default constructed state.

Postconditions: x.get_id() == id() and get_id() returns the value of x.get_id() prior to the assignment.

Returns: *this