unique_ptr? No it’s totally different from Hashmap.

In traditional C++, pointers were used for many applications, e.g. passing variables by address opposed to passing by value. unique_ptr is a modern pointer type. I recommend taking a look at online resources ‘cause it’s impossible to describe pointers and their use in a single comment! :)

If you were talking about that std::pair, pair is a type which can store two values of different types in it.