using System;

​

​

public static class Program

{

    public static void Main()

    {

        string value = "Add";

​

        (value switch

         {

             "Add" => (Action) Add,

             "Subtract" => Subtract,

             _ => throw new ArgumentOutOfRangeException()

         })();

​

        Demo("Subtract");

    }

​

    private static void Demo(string str) =>

        (str switch

         {

             "Add" => (Action) Add,

             "Subtract" => Subtract,

             _ => throw new ArgumentOutOfRangeException()

         })();

​

    private static void Add()

    {

        Console.WriteLine("Add");

    }

​

    private static void Subtract()

    {

        Console.WriteLine("Subtract");

    }

}

​