using System;
using System.Collections.Generic;

namespace DynamicStructureApplication
{
    struct MyStructure
    {
        private readonly string a;
        private readonly string b;
        private readonly IDictionary<string, string> properties;

        public string A
        {
            get { return a; }
        }

        public string B
        {
            get { return b; }
        }

        public string this[string key]
        {
            get { return properties.ContainsKey(key) ? properties[key] : null; }
        }

        public MyStructure(string a, string b)
        {
            this.a = a;
            this.b = b;

            properties = new Dictionary<string, string> { { "A", a }, { "B", b } };
        }
    }

    class Program
    {
        static void Main()
        {
            var myStructure = new MyStructure("A value", "B value");

            Console.WriteLine(myStructure.A);
            Console.WriteLine(myStructure["B"]);
            Console.ReadKey();
        }
    }
}