ValueTypes.cs

using System;

namespace ValueTypes
{
    struct Test
    {
        public int x { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            var a = new Test { x = 1 };
            Use(a, a);
            Console.WriteLine(a.x); // 1
        }

        static void Use(Test b, Test c)
        {
            b.x = 2;
            Console.WriteLine("{0} {1}", b.x, c.x); // 2 1
            c.x = 3;
            Console.WriteLine("{0} {1}", b.x, c.x); // 2 3
        }
    }
}