using System;

using System.Collections.Generic;

using System.Collections;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        B[] bs = new B[4];

        List<B> blist = new List<B>();

        for(int i = 0; i < bs.Length; i++) {

            bs[i] = new B("b: " + i, i*5);

        }

        blist.AddRange(bs);

        for(int i = 0; i < bs.Length; i++) {

            Console.WriteLine(bs[i]);

        }

        IList<A> l = bs;

        for(int i = 0; i < l.Count; i++) {

            Console.WriteLine(l[i]);

        }

        var t = bs.GetType();

        var genericDefinition = blist.GetType().GetGenericTypeDefinition();

        Console.WriteLine("is IList<A>: " +typeof(IList<A>).IsAssignableFrom(t));

        Console.WriteLine("is IList: " +typeof(IList).IsAssignableFrom(t));

        Console.WriteLine("is A[]: " +typeof(A[]).IsAssignableFrom(t));

        Console.WriteLine("generic definition: " + genericDefinition);

        Console.WriteLine("generic definition assignable from: " +typeof(IList<>).IsAssignableFrom(genericDefinition));

        Console.WriteLine("is IList<A>: " +typeof(IList<A>).IsAssignableFrom(blist.GetType()));

        Console.WriteLine("is IList<B>: " +typeof(IList<B>).IsAssignableFrom(blist.GetType()));

        Console.WriteLine("is IList<B>: " +typeof(IList).IsAssignableFrom(blist.GetType()));

    }

    class A {

        public int a;

        public A(int a) {

            this.a=a;

        }

        public A() {}

    }

    class B : A {

        public string b;

        public B(){}

        public B(string b, int a) {

            this.a=a;

            this.b=b;

        }

        public override string ToString(){

            return b + ": " + a;

        }

    }

}