Cache Enum.GetValues in an efficient way (I think :))

EnumHelper.cs

using System;
using System.Linq;

namespace MyFunnyProject
{
    internal static class EnumHelper
    {
        public static class EnumCache<TEnum>
        {
            public readonly static TEnum[] Values = null;

            static EnumCache()
            {
                Values = Enum.GetValues(typeof(TEnum)).Cast<TEnum>().ToArray();
            }
        }

        public static TEnum[] AllValues<TEnum>() where TEnum : struct, IComparable, IFormattable, IConvertible
        {
            return EnumCache<TEnum>.Values;
        }
    }
}