33 Concurrency support library [thread]

33.6 Mutual exclusion [thread.mutex]

33.6.5 Locks [thread.lock]

33.6.5.4 Class template unique_lock [thread.lock.unique]

33.6.5.4.4 Modifiers [thread.lock.unique.mod]

void swap(unique_lock& u) noexcept;
Effects: Swaps the data members of *this and u.
mutex_type* release() noexcept;
Postconditions: pm == 0 and owns == false.
Returns: The previous value of pm.
template<class Mutex> void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept;
Effects: As if by x.swap(y).