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=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD, FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,5a88548f1bcf3510 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,UTF8 Received: by 10.224.205.65 with SMTP id fp1mr3201047qab.4.1353079657472; Fri, 16 Nov 2012 07:27:37 -0800 (PST) Received: by 10.49.94.129 with SMTP id dc1mr1049490qeb.22.1353079657452; Fri, 16 Nov 2012 07:27:37 -0800 (PST) Path: gf5ni327qab.0!nntp.google.com!u2no2429079qal.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Fri, 16 Nov 2012 07:27:37 -0800 (PST) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=195.182.34.201; posting-account=bMuEOQoAAACUUr_ghL3RBIi5neBZ5w_S NNTP-Posting-Host: 195.182.34.201 References: <97a6946f-a707-4dd3-872b-9e851fcf9462@googlegroups.com> <62ba75d8-8a6c-4d75-be37-3322f683714d@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <8998c0eb-c9b1-4501-9163-94172aa4aea0@googlegroups.com> Subject: Re: Overring function and its returned type From: Maciej Sobczak Injection-Date: Fri, 16 Nov 2012 15:27:37 +0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Date: 2012-11-16T07:27:37-08:00 List-Id: W dniu pi=C4=85tek, 16 listopada 2012 13:39:50 UTC+1 u=C5=BCytkownik Peter = C. Chapin napisa=C5=82: > Yet I wonder if=20 > it increases the risk of an "unrelated" change breaking an existing code= =20 > base by introducing an ambiguity where none existed before. I'm not sure - probably, today, it is too late to add this to the language = for the reasons that you have mentioned. However, this feature could have b= een safely added together with other OO-related features, as the whole supp= ort for OO was new in the language and there was no existing codebase that = would break. An interesting property of Ada, and what makes this issue more difficult th= an in C++ is that Ada supports out parameters, which from the language desi= gn point of view should work like return values. Covariant return types are= easy to picture, but covariant out parameters? Hm... Maybe this is where t= hings would start to shake. --=20 Maciej Sobczak * http://www.msobczak.com * http://www.inspirel.com