Architecture Fundamentals, the fourth part

Hi Markus,

at last I found the 15 minutes needed to watch your 4th screencast.

About the open question on the Substitution Principle, I make this kind of reasoning: a specialized instance/class should guarantee to respect the contract subscribed by the more general one.
So it can ask less to the client (OR of the preconditions, that are constraints on the client), but it should give at least the same results (AND of the postconditions, that are constraints on the object).
Is it right?

Anyway, these terms are typical of a Design-by-Contract (DbC) context. I'm curious to know a bit more about your thoughts on DbC.

I tried in some occasions to create a usable DbC mechanism in C++, but without success. Do you have experiences of DbC à-la-Meyer implemented in code? (that I think it's something different from the wider concept of "contract" that you cited in some slides)

A final curiosity: how did you make your beautiful slides? Powerpoint, Openoffice Impress or something else?

Ciao,
Umberto
 

> About the open question on the
> Substitution Principle, `
> Is it right?

yes :-)

> I tried in some occasions to
> create a usable DbC mechanism in
> C++, but without success.

I once did somehting for Java that involved dynamic proxies. Today, in a model-driven world, it is easy of course.

> A final curiosity: how did you
> make your beautiful slides?
> Powerpoint,

Powerpoint, with a lof of help from istockphoto.com :-)

Cheers,
Markus