using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

​

public static class ObjectExtensions

{

    public static void Match<T>(this Option<T> opt, Action<T> good, Action bad) {

        if(opt.isSome()) 

            good(opt.Content[0]);

        else 

            bad();

    } 

    public static V Match<T,V>(this Option<T> opt, Func<T,V> good, Func<V> bad) =>

        opt.isSome()?good(opt.Content[0]) : bad();

}

public class Option<T> : IEnumerable<T>

{

    public T[] Content { get; }

​

    private Option(T[] content)

    {

        this.Content = content;

    }

​

    public static Option<T> Some(T value) => new Option<T>(new[] {value});

​

    public static Option<T> None() => new Option<T>(new T[0]);

​

    public IEnumerator<T> GetEnumerator() =>

        ((IEnumerable<T>) this.Content).GetEnumerator();

​

    IEnumerator IEnumerable.GetEnumerator() => 

        GetEnumerator();

    public bool isSome()=>this.Content.Length!=0;   

​

/**

    public static implicit operator Option<T>(T value) =>

        new Some<T>(value);

​

    public static implicit operator Option<T>(None none) =>

        new None<T>();

        */

}

​

​

public class Car{  

  private string _name;

  public Car(string name){_name = name;}  

  public override string ToString() => _name;

}

public class Person

{

    private DateTime BirthDate { get; }

​

    public Person(DateTime birthDate)

    {

        this.BirthDate = birthDate.Date;

    }

​

    public Option<Car> TryGetCar(DateTime at)

    {

        if (this.BirthDate.AddYears(18) <= at)

            return Option<Car>.Some(new Car("Toyota"));

        return Option<Car>.None();

    }

}

​

public class Program

{

    public static void Main()

    {

        var p = new Person(DateTime.Now.AddYears(-2));

        p = new Person(DateTime.Now.AddYears(-20));

        var car = p.TryGetCar(DateTime.Now);

        //car.Match(a=>Console.WriteLine(a), ()=>Console.WriteLine("can't drive yet"));

        Console.WriteLine(car.Match(a=>a.ToString(), ()=>"you are minor"));                       

    }

}