Why does Enum.ToString not support precisision specifiers like "X2"? : Is there a specific reason, that `Enum.ToString(string)` does not support precision specifiers like `X2` or `D5`? I don't see why I have to explicitely cast it to `int` before being able to convert it to string.

    public enum Number
    {
        Ten = 10
    }

    Console.WriteLine(Number.Ten);                      //OK: Ten
    Console.WriteLine(Number.Ten.ToString());           //OK: Ten
    Console.WriteLine(Number.Ten.ToString("D"));        //OK: 10
    Console.WriteLine(Number.Ten.ToString("D5"));       //Expected 00010 - Failed: System.FormatException, can only be "G","g","X","x","F","f","D" or 
    Console.WriteLine(Number.Ten.ToString("X"));        //OK: 0000000A
    Console.WriteLine(Number.Ten.ToString("X2"));       //Expected 0A - Failed: System.FormatException, can only be "G","g","X","x","F","f","D" or "d"
    Console.WriteLine(10.ToString("X2"));               //OK: 0A
    Console.WriteLine(10.ToString("D5"));               //OK: 00010
    Console.WriteLine(((int)Number.Ten).ToString("X2"));//OK: 0A 
