Re: Booch: iterator invalidation

[Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>]

porton@ex-code.com (Victor Porton) writes:

> I'm not about asserting but about records which have or don't have
> a component dependingly on whether it is the debuging version. 

Hmm. I've never done that for testing. Can you give a real example?
What sort of "additional information" would you add?

I've used "debug storage pools" that report statistics on
allocations/deallocations. I guess that is a form of what you are
talking about here.

Part of the point of "debug stuff" is that it ideally should have
_zero_ impact on the "real code". "pragma Assert" comes very close to
that; the optimizer may do things differently when it is turned on,
but nothing else changes.

> Can variant records be used for this without lost of space
> efficiency?
>
> type T_Internal(Debug: Boolean) is
>   record
>     -- ...
>     case Debug is
>       when True =>
>         -- ... additional debugging stuff
>       when others =>
>         null;
>     end case;
>   end record;
> 
> type T is T_Internal(Use_Debug); -- Use_Debug is a Boolean _constant_
> 
> Will this not bring "additional debugging stuff" in the release
> version (when Use_Debug=False)?

Now everything that uses T_Internal has to specify a Debug
discriminant. To intrusive for my taste.

-- 
-- Stephe