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: Should weak counted reference be able to be strengthened? Date: Sat, 22 Nov 2014 09:42:07 +0100 Organization: cbb software GmbH Message-ID: References: <7d9r3whe43z8$.1f2l3n5cz0zh0$.dlg@40tude.net> <8kPbw.589930$No4.383019@fx19.iad> Reply-To: mailbox@dmitry-kazakov.de NNTP-Posting-Host: wfRpp7ltpEWhI2na6kgpfA.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:23630 Date: 2014-11-22T09:42:07+01:00 List-Id: On Fri, 21 Nov 2014 15:49:42 -0700, Shark8 wrote: > On 21-Nov-14 15:39, Randy Brukardt wrote: >> And anytime you have a bare pointer, you have the possibility of it becoming >> dangling because they're easy to copy. > > ...Isn't that what Limited is for? To prevent copying? But access type are only half-types in Ada. You cannot do type P is limited access T; In a better designed type system, the pointer type interface ("is access") would not be copyable. In order to get a copyable pointer you would have to derive it from the interface of copyable objects ("is private"). -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de