using System;

​

public class Program

{

    public static void Main()

    {

        T<A> g = new T<A>();

        T2 g = new T2();

    }

}

​

public class T<A>

{

    public static extern implicit operator T<A> (A v);

}

​

public class T2

{

    public static extern implicit operator T2 (A v);

}

​

public interface A{}