using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        string[] s = new string[] { "one", "two", "three", "four", "five", "six" };

        IReadOnlyList<Reference<string>> sr = new List<Reference<string>>

        {

          () => s[0],   

          () => s[1],

          () => s[2],

          () => s[3],

          () => s[4],

          () => s[5],

        };

        Console.WriteLine(sr[1]); // == "two"

        s[1] = "two point zero";

        Console.WriteLine(sr[1]); // == "two point zero"

    }

}

​

public class Reference<T>

{

  private readonly Func<T> referenceFunc;

​

  public Reference(Func<T> referenceFunc)

  {

    this.referenceFunc = referenceFunc;

  }

​

  public T Value => this.referenceFunc();

​

  public static implicit operator T(Reference<T> reference)

  {

    return reference.Value;

  }

​

  public static implicit operator Reference<T>(Func<T> referenceFunc)

  {

    return new Reference<T>(referenceFunc);

  }

​

  public override string ToString()

  {

    return this.Value?.ToString();

  }

}

​

public static class ReferenceExtensions

{

  public static void Add<T>(

      this ICollection<Reference<T>> collection,

      Func<T> referenceFunc)

  {

    collection.Add(referenceFunc);

  }

}