A fast & densely stored hashmap and hashset based on robin-hood backward shift deletion for C++17 and later. The classes ankerl::unordered_dense::map and ankerl::unordered_dense::set are (almost) drop ...

// unordered_map<pair<int,int>,string> m; //since hash tables are specified for int,float,char ,string but not specified for vectors, pairs, sets..... // that's why unordered maps are not declared for ...