std::unique_lock::swap
From cppreference.com
                    
                                        
                    < cpp | thread | unique lock
                    
                                                            
                    |   void swap( unique_lock& other ); 
 | 
(since C++11) | |
Exchanges the internal states of the lock objects.
Contents | 
[edit] Parameters
| other | - | the lock to swap the state with | 
[edit] Return value
(none)
[edit] Exceptions
noexcept specification:  
noexcept
  [edit] Example
| This section is incomplete Reason: no example  | 
[edit] See also
|    (C++11) 
 | 
   specialization of std::swap for unique_lock (function template)  |