[fpc-pascal] Find the nature of a pointer

[Marco van de Voort]

> marcov at stack.nl (Marco van de Voort) wrote:
> 
> > > I have a function that will receive a Handle. That handle could be a
> > > pointer to a structure, or a object. Is there any safe way to
> > > discover it's nature?
> > 
> > No you can't. 
> > 
> > > The following code will work when the Handle is an Object or nil,
> > > but will crash the application when the Handle is a structure:
> > 
> > It is not even 100% save for that, some systems use other values
> > instead of nil/0. 
> 
> For example?

Admitted, the examples I know are not-protected mode systems with rom or a
zp on address 0.