Data Type C# Tutorial

using System.Collections.Generic;
using System.ComponentModel;
    public static class PartialComparer
    {
        public static int? Compare(T first, T second)
        {
            return Compare(Comparer.Default, first, second);
        }
        public static int? Compare(IComparer comparer,T first,T second)
        {
            int ret = comparer.Compare(first, second);
            if (ret == 0)
            {
                return null;
            }
            return ret;
        }
    }