std::lock_guard::~lock_guard
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                    < cpp | thread | lock guard
                    
                                                            
                    | ~lock_guard(); | (since C++11) | |
Releases the ownership of the owned mutex or mutexes (since C++17).
| Effectively calls m.unlock() where  | (until C++17) | 
| Effectively calls unlock() on every mutex from the pack of mutexes passed to the  | (since C++17) | 


