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!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Ada Annoyances Date: Mon, 26 Jun 2017 18:38:23 +0200 Organization: Aioe.org NNTP Server Message-ID: References: <1ac5a44b-4423-443a-a7bb-2864d9abe78f@googlegroups.com> <1498048151.20885.28.camel@obry.net> <96174ea5-852d-44e9-8535-7c1eb24d5326@googlegroups.com> <8d3aff06-82df-485f-89e5-a50c326aab05@googlegroups.com> <66aa262e-2ac9-4016-b32d-e9fee14779e1@googlegroups.com> <88e2f18a-0786-4303-a5b8-fe82e8c81dcb@googlegroups.com> <4ad48635-aa1e-45bf-8693-1f77d5fee490@googlegroups.com> <0abaddd0-e64c-4f5b-9f36-e92f75c863ae@googlegroups.com> NNTP-Posting-Host: MajGvm9MbNtGBKE7r8NgYA.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 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 X-Notice: Filtered by postfilter v. 0.8.2 Content-Language: en-US Xref: news.eternal-september.org comp.lang.ada:47128 Date: 2017-06-26T18:38:23+02:00 List-Id: On 2017-06-26 15:24, Maciej Sobczak wrote: >> The example must demonstrate dispatch to the operation of the object's >> type (the ultimate type) from a body defined for the parent type T class. > > Since the Derived object is constructed in a two-step process, the > useObject function is called twice, once from the Base part and once > from the Derived part. Exactly my point. Dispatch is "killed" or misrouted if you want. >> It is apples and oranges. > > If you choose so. In this particular context, apples taste better. Yes, if type-specific constructors is what is needed. Ada's concept of T and T'Class does not prevent having them, if ARG once decides to fix the mess. C++ model cannot be fixed ever. >> As I explained C++ has type-specific >> constructors while Ada's Initialization is a class-wide constructor. You >> cannot compare them. > > I can and I should, since both are used to achieve the same > design-level intent, which is construction of a newly created object. No. Application is very different. A class-wide constructor is called when construction of all instances is complete. E.g. for T'Class it would mean that the specific constructors from T to S are all through. As I explained the sequence is this: T S S'Class / Here the run-time activates a task component of T with \ a discriminant of T'Class T'Class <- Here you call a task entry to pass parameters And for destructor: T'Class < Here you call an entry to ask task to quit < Here the run-time awaits task termination S'Class S T -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de