I am a big java fan but i have to work now on C++ for a project. I intended to you a java hashmap kind of feature in c++. After googling i found there exists no hashmap/hashtable in C++ STL library. But i found these data types: map, unordered\_map, unorderd\_set and hash\_map. hash\_map is microsoft's specific dll/library and remaining are used under STL. i have to work on IBM XL C/C++ compiler. So i can't use microsoft/boost as my company don't recommend them. All i have to use STL specific. Please, provide some info on these collections. What would be best among these STL specifics if i have to choose hashmap functionality? Thanks in advance.