[C++-sig] Re: Problems with dynamic casts

[David Abrahams]

Aaron Bentley <abentley at panoramicfeedback.com> writes:

> Hi,
> I'm having a problem with dynamic casting on an object constructed using 
> Python.  It seems as though the type of an owned object is being lost.
>
> I have a test as follows:
>
> assert (dynamic_cast<element::Comments *>(loc.getElement(elists[0])) 
> !=NULL);
>
> When I invoke it from the constructor of the owning object (the object 
> that owns elists), the test passes.  But when I construct the owning 
> object and then invoke the test through Python, it fails.
>
> I'm using gcc 3.0.4 from Debian stable.
>
> This looks ugly to me.  So far the only explanation I've been able to 
> come up with is memory corruption.

I suggest you reduce your problem to the smallest possible example
that illustrates it.  The answer will probably become obvious to you,
but if it doesn't, please post your example here.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com