220 37317 article Path: news.gmane.org!.POSTED!not-for-mail From: Miguel Ojeda Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Pointer overload for || Date: Mon, 12 Mar 2018 12:41:56 +0100 Lines: 40 Approved: news@gmane.org Message-ID: References: <1fea07df-46a6-4df2-865a-849be8f8d129@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" X-Trace: blaine.gmane.org 1520854817 11806 195.159.176.226 (12 Mar 2018 11:40:17 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 12 Mar 2018 11:40:17 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDRZHGH43YJRBGOPTHKQKGQEUMCUU6Y@isocpp.org Mon Mar 12 12:40:12 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-qt0-f200.google.com ([209.85.216.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1evLoJ-0002wV-Ja for gclcip-std-proposals@m.gmane.org; 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[209.85.220.41]) by mx.google.com with SMTPS id x50sor834018qtx.22.2018.03.12.04.42.17 for (Google Transport Security); Mon, 12 Mar 2018 04:42:17 -0700 (PDT) Received-SPF: pass (google.com: domain of miguel.ojeda.sandonis@gmail.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; X-Received: by 10.237.57.197 with SMTP id m63mr11471368qte.249.1520854936810; Mon, 12 Mar 2018 04:42:16 -0700 (PDT) Original-Received: by 10.200.52.247 with HTTP; Mon, 12 Mar 2018 04:41:56 -0700 (PDT) In-Reply-To: X-Original-Sender: miguel.ojeda.sandonis@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Qee8Mnu6; spf=pass (google.com: domain of miguel.ojeda.sandonis@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=miguel.ojeda.sandonis@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com 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:37317 Archived-At: On Mon, Mar 12, 2018 at 11:42 AM, Richard Hodges wrote: > > Consider: > > p |= new_thing(); > > In the above code, do we mean that we wish to replace p with a new thing if > empty, or does it mean that we wish to merge a new thing into the object > referenced by p? For me ||= would be the replace. But since we don't have ||=, I just picked |=, which indeed looks fishy. Now, what would be a nice experiment would be ||, &&, ||= and &&= with short-circuit semantics, which could be implemented if we had the "expression E" stuff: template operator||=(T & t, E) { if (t) return; t = E; } Then: x ||= new int; would have the expected results. Cheers, Miguel -- 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/CANiq72kNstxnyLTCOBfNorEiyudTijCAUHwH4DsoT14WqcNs4w%40mail.gmail.com. .