Re: NSForm validation

FROM : James Powell
DATE : Wed Nov 13 14:09:04 2002

Aha.  You are correct.  I am surprised, because numberWithInt returns
an NSNumber * and  NSDecimalNumber is a subclass of NSNumber.  In C++,
the compiler does not downcast automatically.  It looks like the
Objective C compiler accommodates downcasts.

This makes sense, given the dynamic nature of Objective C.  It is a
leap of faith to assume that the instance returned by numberWithInt is
actually an NSDecimalNumber instance, but no more than to assume that a
message is defined for a class when it isn't present in the header.

I am also able to answer my remaining question.  I had a silly
unnecessary 'const' keyword in there.  The preferences controller now
compiles without warnings.  Yahoo!  Thank you for your help.

  James