using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var teste = new Teste();

        teste.Run<A>();

    }

}

​

public class Teste{

    private Dictionary<Type, X> map;

    public Teste(){

        map = new Dictionary<Type, X>();

        map.Add(typeof(A), new A());

        map.Add(typeof(B), new B());

    }

    public void Run<T>(){

        map[typeof(T)].DoIt();

    }

}

​

public interface X{

    void DoIt();

}

​

class A: X{

    public void DoIt(){

        Console.WriteLine("sou o A");

    }

}

​

​

class B: X{

    public void DoIt(){

        Console.WriteLine("sou o B");

    }

}