Re: [boost] Proposal: Polymorphic Value Objects

From: Mat Marcus (mat-lists_at_[hidden])
Date: 2007-09-27 22:44:08

On 9/27/07, Mathias Gaunard <mathias.gaunard_at_[hidden]> wrote:
>
> Gottlob Frege wrote:
> > I'm not sure if these polymorphic value objects are the same, but
> > maybe you should look at Adobe's open source poly object:
> > http://opensource.adobe.com/group__poly__related.html
>
> It's quite different.
> Mine allow to use objects of type Derived as if they were variables of
> type Base. Which is just OOP.
>
> From what I've read it seems Adobe ones allows to generate an interface
> on the fly from a C++0x and use it with types that comply to that
> interface, without any relation to inheritance or anything.
> That's more like "dynamic any".

--
Sorry if the research papers cited above misled you as to the capabilities
Adobe poly<> library. Unfortunately, the end-user documentation is not yet
complete. I hope to rectify this soon. In the meantime, I can set the record
straight with respect to the statements that you made above.
The poly<> library that currently ships is written in standard C++. No C++
'0x features are required--it compiles under VC8, gcc-4.20, etc. It does not
require language support for Concepts. Poly<> supports the wrapping of
specific interfaces. In fact, it could be viewed as a generalization of the
any library, allowing any<> to be parametrized with an arbitrary
"interface". Although poly<> shuns of OOP, it does provide for regular,
polymorphic, value-types, without slicing (including support for
downcasting, etc.).
 - Mat