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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: What would you like in Ada202X?
Date: Wed, 25 Apr 2012 21:00:12 -0500
Organization: Jacob Sparre Andersen Research & Innovation
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Date: 2012-04-25T21:00:12-05:00
List-Id: <comp.lang.ada>

"Jacob Sparre Andersen" <sparre@nbi.dk> wrote in message 
news:87sjfsaw1r.fsf@adaheads.sparre-andersen.dk...
...
> One of the ideas discussed was to extend what you can control with
> storage pools.  (I've earlier argued for dereferencing being managed by
> the storage pools. :-)

We tried that for Ada 2012 (see AI05-0141-1) [truth-in-advertising: this was 
almost completely my idea]. We worked on it for a while, but some corners 
are pretty messy (especially the conversion rules), there was problems with 
distributed overhead (often, it's necessary to do these things for all 
storage pools, whether or not they use the facility) and eventually we 
decided that a high-level solution (user-defined references, 4.1.5 in the 
Ada 2012 standard) was better.

Which leads to my question: what can you do with this that you can't do with 
the user-defined reference facility? After all, all you need to do to get 
user-defined *de*references is to create a "managed pointer" type that 
provides appropriate user-defined references. (I believe Christoph Grein has 
or soon will make an Ada 2012 version of his managed pointer packages that 
illustrates how its done.)

After all, anything that encourages people to get explicit access types out 
of their visible specifications is a good thing. (Using access types when 
unnecessary should get people fifty lashes with a wet noodle. :-)

                                        Randy.