Question

I want to accomplish the following:

Entity e;
e.AddComponent<CPosition>(128, 128); //method should instantiate a new CPosition(128,128)
e.AddComponent<CSprite>(some, other, args); //etc

The important part is the AddComponent method. It should attempt to construct the generic type with the arguments passed. I believe C++11’s variadic templates to forward the arguments to the constructor. However, I do not have access to this functionality yet (VS2010).

Does anyone have any idea on how to do this?

Answer 1

Write a bunch of overloads, each taking a different number of parameters.

class Entity
{
public:
 template<typename T>
 void AddComponent() { component_ = new T(); }

 template<typename T, typename T1>
 void AddComponent(T1 t1) { component_ = new T(t1); }

 template<typename T, typename T1, typename T2>
 void AddComponent(T1 t1, T2 t2) { component_ = new T(t1, t2); }

 // etc
 ...
};