Re: access types

[Adam Beneschan <adam@irvine.com>]

On Jul 1, 7:57 am, Robert A Duff <bobd...@shell01.TheWorld.com> wrote:
> "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de> writes:
>
> > On Sat, 30 Jun 2007 21:54:15 -0400, Robert A Duff wrote:
>
> >> Brian May <b...@snoopy.apana.org.au> writes:
>
> >>>         V := U;
>
> >> Try V := U.all'Access.
>
> > No, that won't work, because the access types are pool-specific.
>
> Ah, thanks, I missed that.
>
> >... It is a
> > nasty problem one has to fight all the way when dealing with tagged types
> > and pool-specific access types.
>
> > Sorry, Brian, you probably have to resort to Unchecked_Conversion or else
> > add "all" to your access types.
>
> "Doctor, it hurts when I forget 'all'."
>
> "So don't do that."
>
> ;-)
>
> Access-to-classwide should normally use "all".
> In fact, you won't go too far wrong if you always say "all"
> for all named access-to-variable types.

In fact, if I'm interpreting the manual correctly, once you add "all"
to the access types, then the type conversion should be legal:

   V := X_Reference(U);

[Technically, only X_Reference has to be "access all" for this to be
legal, but you should do this for both access types anyway.]

                          -- Adam