From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,9506bdc34331969a X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news3.google.com!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!club-internet.fr!feedme-small.clubint.net!news.ecp.fr!news.jacob-sparre.dk!pnx.dk!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: put of access type Date: Mon, 31 Aug 2009 20:57:38 -0500 Organization: Jacob Sparre Andersen Message-ID: References: <8sho8596j3qnja38id9ipejk0opkcn5b5m@4ax.com> <4a8cea9c$1@news.post.ch> NNTP-Posting-Host: static-69-95-181-76.mad.choiceone.net X-Trace: munin.nbi.dk 1251770335 28930 69.95.181.76 (1 Sep 2009 01:58:55 GMT) X-Complaints-To: news@jacob-sparre.dk NNTP-Posting-Date: Tue, 1 Sep 2009 01:58:55 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5512 X-RFC2646: Format=Flowed; Original X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Xref: g2news2.google.com comp.lang.ada:8087 Date: 2009-08-31T20:57:38-05:00 List-Id: "Robert A Duff" wrote in message news:wccmy5semnv.fsf@shell01.TheWorld.com... > "Randy Brukardt" writes: > >> "Robert A Duff" wrote in message >> news:wccr5v5xlza.fsf@shell01.TheWorld.com... >> ... >>> I think that still works fine in Ada 95/2005 for pool-specific access >>> types (which is the only kind that existed in Ada 83). The only >>> relevant language change is that you can convert from pool-specific to >>> general. So you have to be able to take your offset, and produce a >>> "full" address, or whatever a general access type is represented as. As >>> far as I can see, the addition of user-defined storage pools to the >>> language is irrelevant here. >> >> I don't see how this could work. There is no call-back to the storage >> pool >> when converting from pool-specific to general access, so how could the >> pool >> make the conversion? > > I'm lost. You said Ada 83 compilers can represent access types as > offsets from some known place. I agree. And I claim Ada 95/2005 > compilers can do the same. Nothing to do with storage pools, which did > not > exist in Ada 83. An Ada 83 compiler can represent *all* access types as offsets from some known place. That's how our old CP/M compilers worked. But since Ada 95 access types can be converted to general access types (without any sort of conversion function in the case of access types with a storage pool), it isn't possible to retain such an implementation in general. I suppose you could use such an implementation for a specific access type with the use of a special implementation-defined pragma (and then you would have to disallow conversions to any other access type, which is not Ada 95), but that is *not* the sort of implementation model that I was thinking of. Randy.