Tests for System.Decimal.GetHashCode()

decimal.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            decimal d0 = 295.50000000000000000000000000m;
            decimal d1 = 295.5m;

            Console.WriteLine("{0}", sizeof(decimal));
            Console.WriteLine("{0} == {1} : {2}", d0, d1, (d0 == d1));
            Console.WriteLine("0x{0:X8} == 0x{1:X8} : {2}", d0.GetHashCode(), d1.GetHashCode()
                              , (d0.GetHashCode() == d1.GetHashCode()));

            decimal[] arr = {
                42m,
                42.0m,
                42.00m,
                42.000m,
                42.0000m,
                42.00000m,
                42.000000m,
                42.0000000m,
                42.00000000m,
                42.000000000m,
                42.0000000000m,
                42.00000000000m,
                42.000000000000m,
                42.0000000000000m,
                42.00000000000000m,
                42.000000000000000m,
                42.0000000000000000m,
                42.00000000000000000m,
                42.000000000000000000m,
                42.0000000000000000000m,
                42.00000000000000000000m,
                42.000000000000000000000m,
                42.0000000000000000000000m,
                42.00000000000000000000000m,
                42.000000000000000000000000m,
                42.0000000000000000000000000m,
                42.00000000000000000000000000m,
                42.000000000000000000000000000m,
            };

            foreach (var m in arr) {
                Console.WriteLine(string.Format(CultureInfo.InvariantCulture,
                  "{0,-32}{1,-20:R}{2:X8}", m, (double)m, m.GetHashCode()
                  ));
            }

            Console.WriteLine("Funny consequences:");
            var h1 = new HashSet<decimal>(arr);
            Console.WriteLine(h1.Count);
            var h2 = new HashSet<double>(arr.Select(m => (double)m));
            Console.WriteLine(h2.Count);
        }
    }
}