using System;

​

public class WrongGUIDTypeException:Exception

{

}

public class BaseGUID 

{

    protected string guid; 

    public string InternalRepresentation

    {

        get 

        {

            return guid; 

        }

    }

    protected static string Name = "Base";

    public BaseGUID(string guid, string name) 

    {

        if (!guid.EndsWith("_"+name)) 

            throw new WrongGUIDTypeException(); 

        this.guid = guid;

    }

    public static BaseGUID NewGuid() 

    {

        return new BaseGUID(Guid.NewGuid().ToString()+"_"+Name, Name); 

    }

    public override bool Equals(object obj)

    {

        if (obj == null || GetType() != obj.GetType())

        {

            return false;

        }

        return ((BaseGUID)obj).InternalRepresentation == guid; 

    }

    public static bool operator ==(BaseGUID x, BaseGUID y)

    {

        return x.Equals(y);

    }

    public static bool operator !=(BaseGUID x, BaseGUID y)

    {

        return !(x==y);

    }

    public override int GetHashCode()

    {

        return guid.GetHashCode(); 

    }

    public override string ToString()

    {

        return guid;    

    }

}

​

public class UserGUID: BaseGUID

{

    protected new static string Name = "User";

    public UserGUID(string guid): base(guid, Name){}

    public new static UserGUID NewGuid() 

    {

        return new UserGUID(Guid.NewGuid().ToString()+"_"+Name); 

    }

}

public class GroupGUID: BaseGUID

{

    protected new static string Name = "Group";

    public GroupGUID(string guid): base(guid, Name){}

    public new static GroupGUID NewGuid() 

    {

        return new GroupGUID(Guid.NewGuid().ToString()+"_"+Name); 

    }

}

​

public class Program

{

    public static void Main()

    {

        var user1 = UserGUID.NewGuid();

        var user2 = UserGUID.NewGuid(); 

        var user3 = new UserGUID(user1.ToString()); 

        var group1 = GroupGUID.NewGuid();

        Console.WriteLine(user1);

        Console.WriteLine(user2);

        Console.WriteLine(user3);

        Console.WriteLine(group1);

​

​

        Console.WriteLine(user1.Equals(user3));

        Console.WriteLine(user2.Equals(user3));

​

        Console.WriteLine(user1==user3);

        Console.WriteLine(user2==user3);

        Console.WriteLine(group1==user1);

        try { 

            var user4 = new UserGUID(group1.ToString());

        } catch (Exception e) {

            Console.WriteLine(e.Message);   

        }

​

​

​

​

    }

}