using System;

using System.Collections.Generic;

​

namespace Example

{

    public interface IThing

    {

    }

​

    public interface IConvertibleThing

    {

        IConvertedThing Convert();

    }

    public interface IConvertedThing

    {

    }

​

    public class ConvertibleThing : IConvertibleThing

    {

        public IThing Thing { get; set; }

        public ConvertibleThing(IThing thing)

        {

            Thing = thing;

        }

        public IConvertedThing Convert()

        {

            return Thing.Convert();

        }

    }

​

    public class ConcreteThing : IThing

    {

    }

​

    public class ConvertedThing : IConvertedThing

    {

    }

​

    public static class ConversionExtensions

    {

        private static Dictionary<Type,Func<IThing,IConvertedThing>> vmt = new Dictionary<Type,Func<IThing,IConvertedThing>>();

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        public static void RegisterConverter(this Type type, Func<IThing,IConvertedThing> func)

        {

            vmt.Add(type,func);

        }

​

        public static IConvertedThing Convert(this IThing source)

        {

            return vmt[source.GetType()](source);

        }

    }

​

​

​

    public class Program

    {

        static public void Main(string[] args)

        { 

            //Initialization

            typeof(ConcreteThing).RegisterConverter( x => new ConvertedThing() );

​

            //Body of program

            IThing thing = new ConcreteThing();

            IConvertibleThing convertibleThing = new ConvertibleThing(thing);

            IConvertedThing convertedThing = convertibleThing.Convert();

        }

    }

}

​