using System;

​

public interface ISampleInterface

{

    void SampleMethod();

}

​

public class ConstraintSimpleClass<G>

    where G : ISampleInterface

{

    G obj;

    public ConstraintSimpleClass(G o)

    {

        obj = o;

    }

​

    public void Call()

    {

        obj.SampleMethod();

    }

}

​

public class SimpleClass : ISampleInterface

{

    public void SampleMethod()

    {

        Console.WriteLine("SampleMethod");

    }

}

​

public class SimpleClass2

{

    public void SampleMethod2()

    {

        Console.WriteLine("SampleMethod2");

    }

}

​

public class GenericInterface

{

    public static void Main(string[] args)

    {

        Console.WriteLine("Generics\nInterface constraints\nEduardo Isaac Ballesteros Muñoz\n");

        SimpleClass simpleClass = new SimpleClass();

        ConstraintSimpleClass<SimpleClass> testConstraintClass = new ConstraintSimpleClass<SimpleClass>(simpleClass);

        testConstraintClass.Call();

        //Compilation Error CS0311

        //The type 'HandsOnObjectOrientedProgramming.SimpleClass2' cannot be used as type parameter 'G' in the generic type or method 'ConstraintSimpleClass<G>'.

        //There is no implicit reference conversion from 'HandsOnObjectOrientedProgramming.SimpleClass2' to 'HandsOnObjectOrientedProgramming.ISampleInterface'.

        //SimpleClass2 simpleClass2 = new SimpleClass2();

        //ConstraintSimpleClass<SimpleClass2> test2 = new ConstraintSimpleClass<SimpleClass2>(simpleClass2);

    }

}