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=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Ada design bug or GNAT bug? Date: Tue, 7 Jul 2015 10:06:19 +0200 Organization: cbb software GmbH Message-ID: <1ncfajhli4bhb$.itfsclre9l62$.dlg@40tude.net> References: <4lrj5zz2u2z.u8x9cf7xzic6.dlg@40tude.net> <58f64fa9-7d0b-44dd-870c-77d9afcb82c4@googlegroups.com> <701370ff-559b-458f-a107-793095a15749@googlegroups.com> Reply-To: mailbox@dmitry-kazakov.de NNTP-Posting-Host: enOx0b+nfqkc2k+TNpOejg.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: 40tude_Dialog/2.0.15.1 X-Notice: Filtered by postfilter v. 0.8.2 Xref: news.eternal-september.org comp.lang.ada:26672 Date: 2015-07-07T10:06:19+02:00 List-Id: On Mon, 6 Jul 2015 05:37:32 -0700 (PDT), Vincent wrote: > Yes it is possible, but it is more work, since one has to encapsulate the access > type into a "handle object". It seems that you conflate by-reference semantics with access types. You don't need access types to have referential semantics, and you don't need referential semantics to have polymorphism. As I side note, I suppose that confusion comes from the idea that an object may have many types. It is not so in Ada and it is not so in any consistently typed system. Most cases when you would need an access type in Ada are language design bugs, which applies to all other languages as well. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de