Just checking to make sure I understand this; the line above would do the validation, and the line below would do the conversion, right?  So when we use this pattern, we'd need to make sure that we had validation enabled for the namespace, right?  Otherwise, if I understood Aria's talk correctly, this is treated more as just a hint or as documentation, rather than actually performing the validation.  Is that right?

If so, then we're also ceding our ability to control the error message / exception flow, right?  Or am I missing something?