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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: limited agregate and limited components default initialization Date: Tue, 3 Apr 2018 10:14:50 +0200 Organization: Aioe.org NNTP Server Message-ID: References: <853b698c-204b-4a5e-a486-b2d7cb664b3a@googlegroups.com> <4834a1b9-6ae2-4806-8022-02bbcc88765f@googlegroups.com> <0db6a65f-9c14-483d-98f9-9fa40e37253f@googlegroups.com> NNTP-Posting-Host: MyFhHs417jM9AgzRpXn7yg.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 Content-Language: en-US X-Notice: Filtered by postfilter v. 0.8.3 Xref: reader02.eternal-september.org comp.lang.ada:51311 Date: 2018-04-03T10:14:50+02:00 List-Id: On 02/04/2018 23:03, Jean-Claude Rostaing wrote: >> Usually I do, it makes operations faster and easier because links are >> never null. I can even have not-null constraint on the links. > Clever ! I never thought about it. > I know about weak references. I read about it. I simply thought I'm not smart enough yet to tackle the issue. You must. There are lots of cases where circular strong references must be broken, weak reference is a way. Other cases are when you don't want to lock the referenced object. Consider monitoring a file. The monitor would hold a weak reference to the file to allow file deletion. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de