220 31819 <14211602.1P4LjlnQMh@tjmaciei-mobl1> article Path: news.gmane.org!.POSTED!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: This variable should not be named: an identifier (not) to remember Date: Tue, 28 Mar 2017 09:43:20 -0700 Lines: 35 Approved: news@gmane.org Message-ID: <14211602.1P4LjlnQMh@tjmaciei-mobl1> References: <985b9b2a-c734-45eb-95f4-db4dc0d309a1@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 Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1490719413 15115 195.159.176.226 (28 Mar 2017 16:43:33 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 28 Mar 2017 16:43:33 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBMNF5LDAKGQE2J3JTJY@isocpp.org Tue Mar 28 18:43:28 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-lf0-f71.google.com ([209.85.215.71]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1csuDN-0003Hk-6Y for gclcip-std-proposals@m.gmane.org; Tue, 28 Mar 2017 18:43:25 +0200 Original-Received: by mail-lf0-f71.google.com with SMTP id k199sf34491023lfg.16 for ; Tue, 28 Mar 2017 09:43:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=YH8OY42Kw8BrqPTpGKrXlnuRmhC/o40hpEYQUK48LpI=; b=rYNqDHPPFUL31m11gJjGBvo9D/CBfYoIGxg0mowQw1zWn6oAUeN47+z0lpTWMPxMxt Qtgia8TVHBoPMb09hsALKxiELFZewTb2vLFCK48yp0faD7IkHcNvcNSNTnAXsoag7CxR tTt/vVkgXZ6e5sCUd0h7qUb/JNi+NxQ4kAvYYwFifm8LClXW7T9q95ytlIpxBAYez8Wi vzNKUVqTvkaGVz7CjMWh2n622Vl+kocGeT247VeRYJYuslKBsfNvaJ1Gqb9+R9FG8zVN lzwcFq+h/QY8SyWZtTmdgUITMmWyKdMsPF0ap/lDpYkw9prxlOc43CKvfqINfghwmtKd mGzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=YH8OY42Kw8BrqPTpGKrXlnuRmhC/o40hpEYQUK48LpI=; b=WSFdy7JZq4qnLGymyz/kzz4tx5M9u4so8EezdO7VdHljcYqY4ni41oZukSkqgig8h2 bBAP/zxHnz8pEOLQFBpzBbOEHFGzD3nOSr8LYGfJ4VSnkFODeDugFtmLoG2LKE+lm+9+ xEKA1nr4KyZBvMmHZWgZZbubxvHlWdyZuSyG4c2vbJIu9eD8YUcf/IeNlt+/Xm1GWprU AZNukMAs++UiOChDYNbjBNHQALRMxc8p8ZM0csnEPMqnbQbNIdronaZP80QYpL8XnIhe SgysCjxOxBhdq+PEIuEk55USohkS7Gt33FD57Eq+T5hVtB9qNEGh62B4gCcqFtY19VMC QND X-Gm-Message-State: AFeK/H0QMttJiIXPUfmByjB8leDehWPOPE3azCTFhMuteeppdKN3iqkIXrW+x9WCaMBckg== X-Received: by 10.46.1.12 with SMTP id 12mr669208ljb.30.1490719411540; Tue, 28 Mar 2017 09:43:31 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.25.227.79 with SMTP id c15ls1380053lfk.49.gmail; Tue, 28 Mar 2017 09:43:29 -0700 (PDT) X-Received: by 10.25.242.1 with SMTP id q1mr13761394lfh.22.1490719409677; Tue, 28 Mar 2017 09:43:29 -0700 (PDT) Original-Received: from gondolin.macieira.info (gondolin.macieira.info. [78.47.120.188]) by mx.google.com with ESMTP id v1si2160810ljd.154.2017.03.28.09.43.29 for ; Tue, 28 Mar 2017 09:43:29 -0700 (PDT) Received-SPF: pass (google.com: domain of thiago@macieira.org designates 78.47.120.188 as permitted sender) client-ip=78.47.120.188; Original-Received: from tjmaciei-mobl1.localnet (unknown [134.134.139.78]) by gondolin.macieira.info (Postfix) with ESMTPSA id 9BBAE11B82B for ; Tue, 28 Mar 2017 09:43:28 -0700 (PDT) In-Reply-To: X-Original-Sender: thiago@macieira.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of thiago@macieira.org designates 78.47.120.188 as permitted sender) smtp.mailfrom=thiago@macieira.org Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: 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:31819 Archived-At: On ter=C3=A7a-feira, 28 de mar=C3=A7o de 2017 09:27:34 PDT Zhihao Yuan wrot= e: > here you mean to *preserve* the result object, but when > you write >=20 > auto [__, a] =3D get_tuple(...); >=20 > you mean to *ignore* a part of the result object, so > physically, just like std::ignore, I don't expect __ here > to issue a call to get(obj), nor an access to a subobject. > I don't think the *preserving* semantics can fulfill the > *ignoring* demand. It has no difference, because the structured binding is actually a *binding= *,=20 so there's difference to object creation or retention. The result from=20 get_tuple is assigned to an anonymous object and all its members are retain= ed.=20 Then it's decomposed into two elements: an anonymous one (can't be accessed= )=20 and a. --=20 Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org Software Architect - Intel Open Source Technology Center --=20 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 e= mail 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/14211602.1P4LjlnQMh%40tjmaciei-mobl1. .