Re: How do I get this to work??

[Brian Rogoff <bpr@shell5.ba.best.com>]

On Sat, 9 Jan 1999, Chris Warwick wrote:
> In article <771bl9$sla$1@nnrp1.dejanews.com>, robert_dewar@my-dejanews.com wrote:
> 
> >You can't have it both ways, If you insist on structuring
> >your program in a manner that leaves it open to the
> >possibilities of dangling pointers, then you have to use
> >Unchecked_Access. 
> 
> I guess this where I get confused. If I want to pass a pointer amoungst these 
> functions/procedures I have to define the type at the package level. As a 
> result there is no way for someone to define an instance of the pointer at a 
> lower level, i.e., as a local variable within a procedure. Another way to get 

I'm jumping into the middle of this, so I don't have the context, but one
trick I use to define access types at a lower level is to define the
access types in a generic package and instantiate them in the scope that
I need them. This trick is especially useful with access to subprogram
types, which don't permit an Unchecked_Access.

> I've got it working... My uneasyness stems from the fact that when I ran into 
> unchecked_conversion I was able to get someone to explain to me how it really 
> was "supposed" to work, and once I understood, I agreed. Thus far I still do 
> not understand how a package can export a "useful" pointer definition...

By making the package (a parameterless, if necessary) generic, and
instantiating it where you need it?

-- Brian