Special Standard Containers Special Containers Special Containers

pair<A,B> contains 2 values of same or different type
tuple<A,B,C,…>  C++11 contains many values of same or different type
optional<T>  C++17 contains either one value of type T or no value
variant<A,B,C,…>  C++17 contains one value of either type A or type B or type C, …
any C++17 contains one value of any type