Ok...so this may be a touch half baked...I found some cases where it's going
to cause problems.
When you're trying to use just a generic Object as an element in say a List,
there's no way to make the List of an aggregate type. I'll have to refine
the model a little more and see what can be done to resolve this.
--
David J. Graff
Broadvision/Atlanta - Principal Consultant
mailto:[EMAIL PROTECTED]
Phone: (678) 427-5412
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> -----Original Message-----
> From: Graff, David
> Sent: Monday, May 07, 2001 8:57 AM
> To: '[EMAIL PROTECTED]'
> Subject: [htdig-dev] Question about implementation of base
> Object class
> and it's drive d classes
>
>
> I've been running this one over in my head all weekend. And
> to tell you the
> truth, it bothers me.
>
> HtVector and HtHeap both inherit Object. Object defines the
> member Copy()
> as a virtual function with a return type of Object*.
> HtVector and HtHeap
> both implement Copy() as HtVector* Copy and HtHeap* Copy
> respectively. To
> me that breaks the C++ model for redefining methods. Sparc C
> seems to agree
> with me as well giving me a hard error in compilation.
>
> I have a solution I'd like to propose that would resolve the
> issue but might
> break something else and I'd like to hear some feedback on it.
>
> What if we made Object a template class like the following:
>
> template <class T> class Object {
> public:
> Object() {}
> virtual ~Object() {}
>
> virtual int compare(const T&) const = 0;
>
> virtual T *Copy() const { return NULL; }
> };
>
> The only problem with this is that we'd lose the method
> virtual int compare(Object&) const;
>
> Now one line of code that bothers me SEVERELY is in htString.h:109
>
> int compare(const Object& s) const { return compare((const
> String&)s); }
>
> There is NO checking to see if Object is infact a string just
> a blind cast
> to a String reference. THAT is dangerous to say the least.
>
> Can anyone tell me a reason why we could not just ditch the
> virtual compare
> method I mentioned above and switch to a template?
>
> Thanks guys & gals.
> --
> David J. Graff
> Broadvision/Atlanta - Principal Consultant
> mailto:[EMAIL PROTECTED]
> Phone: (678) 427-5412
> This message is intended only for the use of the Addressee
> and may contain
> information that is PRIVILEGED and CONFIDENTIAL. If you are
> not the intended
> recipient, dissemination of this communication is prohibited.
> If you have
> received this communication in error, please erase all copies
> of the message
> and its attachments and notify us immediately.
>
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David J Graff.vcf
