std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>::key_eq
From cppreference.com
                    
                                        
                    < cpp | container | unordered multimap
                    
                                                            
                    
|   key_equal key_eq() const;  | 
(since C++11) | |
Returns the function that compares keys for equality.
Parameters
(none)
Return value
The key comparison function.
Complexity
Constant.
See also
|    returns function used to hash the keys   (public member function)  |