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: derived formal types and known discriminants Date: Thu, 29 Jun 2017 16:39:44 +0200 Organization: Aioe.org NNTP Server Message-ID: References: <82a59ee9-8d55-4c73-9daf-e9f7d9ab8a8f@googlegroups.com> NNTP-Posting-Host: vZYCW951TbFitc4GdEwQJg.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/52.2.1 X-Notice: Filtered by postfilter v. 0.8.2 Content-Language: en-US Xref: news.eternal-september.org comp.lang.ada:47177 Date: 2017-06-29T16:39:44+02:00 List-Id: On 29/06/2017 16:15, sbelmont700@gmail.com wrote: > You imply that the feature is little-used, but isn't this (one of) > the primary mechanisms for MI via the so-called "mixin"? In Mr. > Taft's paper from 1994 ("Multiple Inheritance in Ada 9X"), he lists > the three common cases, of which #2 is the "generic with a formal > derived type" method, i.e. instead of having C extend both A and B, > you make one of the parents a generic that extends a formal derived > type of the other, and than have the child and extend that. Speaking from my sad experience it creates such a mess no real-life project can allow. I guess other people either tried it like me or were wise enough not to. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de