using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

//https://stackoverflow.com/questions/52819620/fluence-builder-inheritance-with-recursive-generics

​

namespace Creational.Builder2

{

    public class Person

    {

        public string Name;

​

        public string Position;

​

        //  public class Builder : PersonInfoBuilder<Builder> //change this line

        public class Builder : PersonJobBuilder<Builder>

        {

​

        }

​

        public static Builder New => new Builder();

​

        public override string ToString()

        {

            return $"{nameof(Name)}: {Name}, {nameof(Position)}: {Position}";

        }

    }

​

    public abstract class PersonBuilder          

    {

        protected Person person = new Person();

        public Person Build()

        {

            return person;

        }

    }

​

    // class Foo : Bar<Foo>

    public class PersonInfoBuilder<SELF> : PersonBuilder 

      where SELF : PersonInfoBuilder<SELF>

    {

        public SELF Called(string name)

        {

            person.Name = name;

            return (SELF)this;

        }

    }

​

    public class PersonJobBuilder<SELF> : PersonInfoBuilder<SELF>

      where SELF : PersonJobBuilder<SELF>

    {

        public SELF WorksAsA(string position)

        {

            person.Position = position;

            return (SELF)this;

        }

    }

​

    internal class Program

    {

        public static void Main()

        {

            var me = Person.New

                 .Called("Harry")

                 .WorksAsA("Testing")

                 .Build();

            Console.WriteLine(me);

​

            var builder = new Person.Builder();

            var person = builder.WorksAsA("d");

            Console.WriteLine(person);

        }

    }

}

​

/*

  output:

 Name: Harry, Position: Testing

Creational.Builder.Person+Builder

 */

​