From: Robert Kawulak (kawulak_at_[hidden])
Date: 2005-09-26 05:33:20
Hi,
> Just so you know, it's my feeling that the 'range
> constraint' is the
> most frequent and most of the more complicated cases you can
> imagine don't
> come up that much in practice. I'm not even sure it's really worth
> supporting.
It seems to be the most frequent and most important, but I think we
shouldn't close the door for the other
not-so-common-yet-occuring-from-time-to-time constraints, because it's easy
to let them work. One day you may need to have a type for odd numbers only,
for lowercase strings only or for strings containing numbers only, and the
template will be ready here :)
> The most important thing is to allow
> customization of the error
> handling and set it up so the details of the constraint
> violation can (eg: min
> or max) can be determined. Again I've been skimming so I
> don't know if your
> code does this or not.
Customisation of the error handling - yes, reporting details of constraints
violation - not implemented, but very easily supported.
> That's not good. I guess you'd need need one of the policies
> to specify the
> default value if it is allowed. In the date-time
> constrained_value there is
> no default constructor as I recall.
Right, in my implementation if you want to use default construction, the
policy must supply initialize() member for this purpose.
Best regards,
Robert