Re: Extension of non-limited type needs limited component

[Robert A Duff <bobduff@shell01.TheWorld.com>]

michael.jackson5@virgin.net (Mike) writes:

> Am I allowed to create my own pointer-to-limited type and de-reference
> it for use later?

Yes.  You just need to say ".all" whenever you want to call the
preexisting procedures.

The only problem with using a pointer that then you have to worry about
storage management.  You'll probably end up allocating the thing in the
heap (with "new"), and then you have to worry about deallocating it.

>... Wouldn't the act of de-referenceing be an implicit
> assignment?

No.  "X.all" returns the heap object that the pointer points at.
It does not fetch the value out of that object.  The fetch operation is
really what limited types want to disallow.

When you say P(X.all), the heap object will be passed by reference if it
is really limited -- no copy is made.

- Bob