std::unique_lock<Mutex>::mutex
From cppreference.com
                    
                                        
                    < cpp | thread | unique lock
                    
                                                            
                    |   mutex_type* mutex() const noexcept;  | 
(since C++11) | |
Returns a pointer to the associated mutex, or a null pointer if there is no associated mutex.
Parameters
(none)
Return value
Pointer to the associated mutex or a null pointer if there is no associated mutex.
Example
| This section is incomplete Reason: no example  |