Templates?

  
template<typename SomeType>
class Twin {
 SomeType first_twin;
 SomeType second_twin;
};

class Object;//some object


void main() {
 Twin<int> int_twin; //generate a twin of ints

 int_twin.first_twin is an int, and you can use it as int;
 int_twin.second_twin is an int as well..;
 Twin<Object> obj_twin; //generate a twin of objects

 obj_twin.first_twin is here an 'Object';
 obj_twin.second_twin as well..;
}
  

  
#include <vector>
...
vector<Object> object_array; //creates a dynamic sizeable array of Objects

Object x; //creates an Object

object_array.push_back(x); //adds the Object to the array