using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    class Model {}

    class View {}

    class View<M> : View where M : Model {}

    class ConcreteModel : Model {}

    class ConcreteView : View<ConcreteModel> {}

    static View CreateView<M>(M model) where M : Model {

        Console.WriteLine(typeof(M));

        Console.WriteLine(model.GetType());

        if (model is ConcreteModel) {

            return new ConcreteView();

        } else {

            return new View(); 

        }

    }

    public static void Main()

    {

        // Run-time.

        Model model = new ConcreteModel();

        View view = CreateView(model);

        Console.WriteLine(view.GetType());

        Console.WriteLine("---");

        // Compile-time.

        ConcreteModel concreteModel = new ConcreteModel();

        View concreteView = CreateView(concreteModel);

        Console.WriteLine(concreteView.GetType());

    }

}