220 38162 <1660351.5grH1viArP@tjmaciei-mobl1> article Path: news.gmane.org!.POSTED!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: memcpy/memset/etc overloads for volatile memory Date: Wed, 23 May 2018 13:07:57 -0300 Lines: 30 Approved: news@gmane.org Message-ID: <1660351.5grH1viArP@tjmaciei-mobl1> References: <1802764.OhHZxBL3Cz@tjmaciei-mobl1> 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 1527091554 3248 195.159.176.226 (23 May 2018 16:05:54 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 23 May 2018 16:05:54 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBYFDS3MAKGQEP6DW7YA@isocpp.org Wed May 23 18:05:50 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-qk0-f200.google.com ([209.85.220.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fLWGs-0000kt-Hu for gclcip-std-proposals@m.gmane.org; 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[2001:19f0:5:2221::1:3]) by mx.google.com with ESMTPS id c185-v6si692699qkf.135.2018.05.23.09.08.00 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 May 2018 09:08:00 -0700 (PDT) Received-SPF: pass (google.com: domain of thiago@macieira.org designates 2001:19f0:5:2221::1:3 as permitted sender) client-ip=2001:19f0:5:2221::1:3; Original-Received: from tjmaciei-mobl1.localnet (189-69-95-251.dsl.telesp.net.br [189.69.95.251]) by smtp.macieira.info (Postfix) with ESMTPSA id 21AF5EDC3 for ; Wed, 23 May 2018 09:07:59 -0700 (PDT) In-Reply-To: <1802764.OhHZxBL3Cz@tjmaciei-mobl1> X-Original-Sender: thiago@macieira.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of thiago@macieira.org designates 2001:19f0:5:2221::1:3 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-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:38162 Archived-At: On Wednesday, 23 May 2018 13:05:07 -03 Thiago Macieira wrote: > Sorry, but my point is that to write: > > for (size_t i = 0; i < n; ++i) > dst[i] = src[i]; By the way, this should be what std::copy_n(src, n, dst); Should generate for volatile chars, but the compilation fails with both libc++ and libstdc++, as both try too aggressively to use memmove. Since I don't see any requirement in the standard besides src and dst being valid InputIterator and OutputIterator respectively, I believe that's a bug in both implementations. Microsoft's compiles. See https://godbolt.org/g/7yMhRy. -- Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org Software Architect - Intel Open Source Technology Center -- 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/1660351.5grH1viArP%40tjmaciei-mobl1. .