220 36574 article Path: news.gmane.org!.POSTED!not-for-mail From: Ville Voutilainen Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Should the Default Allocator use Uniform Initialization? 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[209.85.220.65]) by mx.google.com with SMTPS id k36sor2439139otb.171.2018.01.08.09.25.17 for (Google Transport Security); Mon, 08 Jan 2018 09:25:17 -0800 (PST) Received-SPF: pass (google.com: domain of ville.voutilainen@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; X-Received: by 10.157.4.230 with SMTP id 93mr6912999otm.291.1515432316699; Mon, 08 Jan 2018 09:25:16 -0800 (PST) Original-Received: by 10.157.43.248 with HTTP; Mon, 8 Jan 2018 09:25:16 -0800 (PST) In-Reply-To: X-Original-Sender: ville.voutilainen@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=ld4HdM/X; spf=pass (google.com: domain of ville.voutilainen@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=ville.voutilainen@gmail.com; dmarc=pass (p=NONE sp=NONE 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:36574 Archived-At: On 8 January 2018 at 18:25, Nicol Bolas wrote: > > > On Monday, January 8, 2018 at 11:16:36 AM UTC-5, Jakob Riedle wrote: >> >> Hello Folks, >> >> currently, std::allocator (and std::allocator_traits) use value >> initialization, that is placement new (p) (). >> . >> However, this prevents it from initializing aggregates (see here). >> >> Since using uniform initialization is the recommended (as of C++14) way of >> initializing variables, > > > Recommended by whom? It's broken. Uniform initialization can hide > constructors. Its narrowing restrictions, especially with forwarded > argument, play havoc with initialization. > > Uniform initialization is good syntax bound to bad initialization rules. It > is not some default recommendation for initializing variables. > >> >> std::allocator and std::allocator_traits should follow this guideline. >> I think, we can all agree, that in general, not being able to emplace() >> aggregates is an incompleteness. > > > Yes. That's why LWG-2089 exists. I've written something that covers the > proposed solution, corrects it, and thoroughly investigates all of the > issues around it and pretty much every possible language and library > solutions. > > And if you have another possible solution not on that list, please let me > know. I plan to propose allowing paren-initializing aggregates. That proposal should appear in the pre-Jacksonville mailing. -- 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/CAFk2RUbtYTmHWvwWGUgaL8%3DJgOhDz8W4CRio7Xq62nYt2oMhtg%40mail.gmail.com. .