using System;

///Practical functional programing in C#

//functional programming in modern Web Application development using Asp.Net Core and 

//Domain Driven Design with the language-extfunctional library in C#

//https://leanpub.com/practical-functional-CSharp       

public class Program

{ 

    public class Id<T>

 {

        public T Value { get; set; }

        public Id(T value) => Value = value;

       public T1 MatchWith<T1>(Func<T, T1> callback) => callback(Value);

        public void MatchWith(Action<T> callback) => callback(Value);

 }

    public static void Main()

    {

​

        new Id<int>(3). MatchWith(Console.WriteLine);

​

        Console.WriteLine( new Id<int>(3).Value) ;  // Instead of this 

​

        Console.WriteLine("Hello World");

    }

}