System.Uri.Uri.FromHex C# (CSharp) Method

		public static int FromHex (char digit) 
		{
			if ('0' <= digit && digit <= '9') {
				return (int) (digit - '0');
			}
				
			if ('a' <= digit && digit <= 'f')
				return (int) (digit - 'a' + 10);

			if ('A' <= digit && digit <= 'F')
				return (int) (digit - 'A' + 10);
				
			throw new ArgumentException ("digit");
		}