Re: virtual destructors

[Simon Wright <simon@pushface.org>]

Stephen Leake <Stephe.Leake@nasa.gov> writes:

> Simon Wright <simon@pushface.org> writes:
> 
> > Stephen Leake <Stephe.Leake@nasa.gov> writes:
> > 
> > > You also need to ensure that both access types use the same storage
> > > pool. Something like:
> > > 
> > > for CDerived'Storage_Pool use CBase'Storage_Pool.
> > 
> > I don't see why? there was no attempt I could see to convert between
> > the classwide pointer types?
> 
> In general, the compiler can use different storage pools for each
> access type. 
> 
> If you do:
> 
> A : CBase := new Derived'();
> 
> and then later:
> 
> Free (A);
> 
> The compiler might allocation from CDerived_Storage_Pool, and then
> deallocate from CBase_Storage_Pool. Very bad. 

Indeed, I hadn't spotted that particular problem (I was looking at the
procedures, not the main program). Sorry.