std::function<R(Args...)>::~function
From cppreference.com
                    
                                        
                    < cpp | utility | functional | function
                    
                                                            
                    | ~function(); | (since C++11) | |
Destroys the std::function instance. If the std::function is not empty, its target is destroyed also.
See also
| (C++23) | destroys a std::move_only_functionobject(public member function of std::move_only_function<R(Args...) cv ref noexcept(noex)>) |