CustomOrdinalIgnoreCaseComparer

	class CustomOrdinalIgnoreCaseComparer : IEqualityComparer<string>
	{
		static int ToLower (int c)
		{
			if (c >= 0x41 && c <= 0x5A)
				return c + 0x20;

			return c;
		}

		public bool Equals (string x, string y)
		{
			if (x.Length != y.Length)
				return false;

			for (int i = 0; i < x.Length; i++) {
				if (ToLower (x[i]) != ToLower (y[i]))
					return false;
			}

			return true;
		}

		public int GetHashCode (string obj)
		{
			unsafe {
				fixed (char *src = obj) {
					int hash1 = 5381;
					int hash2 = hash1;
					char *s = src;
					int c;

					while ((c = s[0]) != 0) {
						hash1 = ((hash1 << 5) + hash1) ^ ToLower (c);
						c = s[1];
						if (c == 0)
							break;
						hash2 = ((hash2 << 5) + hash2) ^ ToLower (c);
						s += 2;
					}

					return hash1 + (hash2 * 1566083941);
				}
			}
		}
	}