220 37292 <05da71c2-80cf-63dd-b2c6-8cd342db5140@gmail.com> article Path: news.gmane.org!.POSTED!not-for-mail From: Jefferson Carpenter Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Pointer overload for || Date: Sun, 11 Mar 2018 04:40:05 -0500 Lines: 47 Approved: news@gmane.org Message-ID: <05da71c2-80cf-63dd-b2c6-8cd342db5140@gmail.com> 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"; format=flowed X-Trace: blaine.gmane.org 1520761094 31159 195.159.176.226 (11 Mar 2018 09:38:14 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sun, 11 Mar 2018 09:38:14 +0000 (UTC) User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDMNDCNA64OBB6XSSPKQKGQE6I3YBLY@isocpp.org Sun Mar 11 10:38:10 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-it0-f69.google.com ([209.85.214.69]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1euxQg-0007xE-Gn for gclcip-std-proposals@m.gmane.org; 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([2601:441:8680:4631:ecd0:a4aa:6a04:1146]) by smtp.gmail.com with ESMTPSA id n132sm1236015itn.28.2018.03.11.01.40.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 11 Mar 2018 01:40:09 -0800 (PST) In-Reply-To: Content-Language: en-US X-Original-Sender: jeffersonCarpenter2@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=btsZ68oD; spf=pass (google.com: domain of jeffersoncarpenter2@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=jeffersoncarpenter2@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:37292 Archived-At: On 3/11/2018 4:16 AM, Nicolas Lesser wrote: > I don't see the point. How is your if not succinct? > > if (!ptr) > ptr = new int; Yeah, I guess the if statement is good enough. I agree, there's no need to add the python- or ruby-like form of the if statement. BTW the only reason I was hesitant to use the ternary operator, "ptr = ptr ? ptr : new int", is just because you would need to write ptr three times, yuck. However, the ternary operator does have the simple advantage over the if statement that you can use it at the expression level. > Also that inverted logic has a high chance of confusing anyone who comes > across it, and it some cases, it is not even clear which or operator you > choose. > > var = var || allocate(); > > If allocate doesn't return a pointer, but a boolean (or due to a refactor > it changes) then the expression above would no longer do the right thing: > assign 1 to var if either expression is true, which is not expected. I don't know precisely what you mean by "inverted" logic, but I don't agree that it would necessarily confuse anyone who comes across it - it would just be unfamiliar syntax, which they would look up. It's true that the expression would compile regardless of whether allocate() returns a bool or a pointer, which could cause a surprising bug due to implicit pointer-to-bool conversion, but I don't feel like that's very likely, or that it would be very likely that a refactor would cause a problem there either. Specifically if your allocate() is changed from returning a pointer to returning a bool during a refactor, its signature would change in other ways that would cause a compile error there, i.e. taking a reference to the pointer to allocate as an argument instead of returning it. Jefferson Carpenter -- 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/05da71c2-80cf-63dd-b2c6-8cd342db5140%40gmail.com. .