using System;

​

public interface IItem

{

    string id {get;set;}

}

​

​

public class Item : IItem

{

    public string id{get;set;}

}

​

public class BaseFactory

{

    public DelegateHolder.MakeWithID funcA;

    public DelegateHolder.MakeWithIDAndOther funcB;

}

​

public class TypedFactory<T> : BaseFactory

    where T : IItem, new()

{

        public TypedFactory()

        {

            funcA = makeNew;

            funcB = makeNewFromOther;

        }

        public T makeNew(string itemId)

        {

            T _item = new T();

            _item.id = itemId;

            return _item;

        }

        public T makeNewFromOther(string itemId, T other)

        {

            T _item = new T();

            _item.id = itemId;

            return _item;

        }

}

​

public class DelegateHolder

{

    public delegate IItem MakeWithID(string id);

    public delegate IItem MakeWithIDAndOther(string id, IItem other);

}

​

public class Program

{

    public static void Main()

    {

        var x = new TypedFactory<Item>();

        BaseFactory factory = x;

        IItem someItem = factory.funcA("I am alive");

        Console.WriteLine(someItem.id);

        Console.WriteLine(factory.funcB("I am alive too", someItem).id);

    }

}