std::queue::empty
From cppreference.com
                    
                                        
                    
                    
                                                            
                    
|   bool empty() const;  | 
(since {std}) | |
Checks if the underlying container has no elements, i.e. whether c.empty().
Contents | 
[edit] Parameters
(none)
[edit] Return value
true if the underlying container is empty, false otherwise
[edit] Complexity
Constant
[edit] See also
|    returns the number of elements   (public member function)  | |