220 39422 article Path: news.gmane.org!.POSTED!not-for-mail From: Bo Persson Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Contract attributes and trailing return types Date: Thu, 26 Jul 2018 23:11:42 +0200 Lines: 52 Approved: news@gmane.org Message-ID: References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed X-Trace: blaine.gmane.org 1532639388 22015 195.159.176.226 (26 Jul 2018 21:09:48 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 26 Jul 2018 21:09:48 +0000 (UTC) User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCZ6RLW3UIKBBGHS5DNAKGQE6NON3ZA@isocpp.org Thu Jul 26 23:09:44 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-lj1-f200.google.com ([209.85.208.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1finW3-0005e0-3x for gclcip-std-proposals@m.gmane.org; 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Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1finVz-0005Z8-De for std-proposals@isocpp.org; Thu, 26 Jul 2018 23:09:39 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 45 Original-X-Complaints-To: usenet@blaine.gmane.org In-Reply-To: Content-Language: sv X-Original-Sender: gclcip-std-proposals@m.gmane.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 195.159.176.226 is neither permitted nor denied by best guess record for domain of gclcip-std-proposals@m.gmane.org) smtp.mailfrom=gclcip-std-proposals@m.gmane.org Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:39422 Archived-At: On 2018-07-26 22:02, 'Hamza Sood' via ISO C++ Standard - Future Proposals wrote: > If I'm interpreting the current draft standard correctly, it looks like > contract attributes don't work particularly well with trailing return types. > > E.g. here's an example from the proposal, re-written with a trailing > return type: > | > > *auto f(intx,inty) > [[expects:x>0]] > [[expects:y!=0]] > [[ensures result:result >x+y]]->int; > * > > | > > The return type ends up really far away from the rest of the function > declaration, which makes it very difficult to spot. > > I think it'd be better if contract attributes applied to a trailing > return type are considered part of the function declaration, which would > mean that the above could be written as: > | > > *auto f(intx,inty)->int > [[expects:x>0]] > [[expects:y!=0]] > [[ensures result:result >x+y]];* > > | On the other hand, you can alredy have template auto f(Types&&... x) const volatile && noexcept(std::conjunction_v...>) -> int; So why not add some more stuff before the -> ? :-) Or perhaps we need a general cleanup here, not just for contracts? Bo Persson -- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/pjddad%24kii%241%40blaine.gmane.org. .