220 40109 <2b61d38aa27b27cdd8d87983ae0d56ed@example.net> article Path: news.gmane.org!.POSTED!not-for-mail From: Andreas Fertig Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: for loops w/ reverse iteration Date: Fri, 31 Aug 2018 09:32:20 +0200 Lines: 80 Approved: news@gmane.org Message-ID: <2b61d38aa27b27cdd8d87983ae0d56ed@example.net> References: <5e6ffea4-4c7b-4da1-9602-bbd670ce1f8a@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 Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1535700618 18936 195.159.176.226 (31 Aug 2018 07:30:18 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 31 Aug 2018 07:30:18 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC73HFG7UEARBB66UPOAKGQE3KEHK6A@isocpp.org Fri Aug 31 09:30:14 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wr1-f71.google.com ([209.85.221.71]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fvdsj-0004pt-RR for gclcip-std-proposals@m.gmane.org; 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[212.227.17.24]) by mx.google.com with ESMTPS id r15-v6si8191471wrm.102.2018.08.31.00.32.22 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 31 Aug 2018 00:32:23 -0700 (PDT) Received-SPF: neutral (google.com: 212.227.17.24 is neither permitted nor denied by best guess record for domain of src@andyf.de) client-ip=212.227.17.24; Original-Received: from lins.andyf.de ([92.116.146.206]) by mrelayeu.kundenserver.de (mreue103 [212.227.15.183]) with ESMTPSA (Nemesis) id 0LfGuG-1fXHXK15FA-00orxW for ; Fri, 31 Aug 2018 09:32:22 +0200 X-PHP-Originating-Script: 1000:rcmail.php Mail-Reply-To: src@andyf.de In-Reply-To: <5e6ffea4-4c7b-4da1-9602-bbd670ce1f8a@isocpp.org> X-Sender: src@andyf.de X-Provags-ID: V03:K1:SkMapiU0hmKWm0kapLBHMv8umLI14/A3gJIM0609v+One3B//2U kbJSADPr8VjXVHgsxEQe19JJ5SRtJukHmUSaHovbpsOWU9EFdMAGhf/4iezUi+PMY59J0JC Vox+bz0BkvmwK17XEQKriV823KgKJhbZ24dpr0Qm6H2wDGrmCYV5hrikxsWd0b2+HT68qju 72Z4KGugSlgU3+w4vcd8g== X-UI-Out-Filterresults: notjunk:1;V01:K0:0o2lgLc3Jyo=:W3Ub5f7uxLEr9kaW8cdr2i Q16jmFWZWDPKJFbv/YX7HtIB7J9S4nJiIb2tfqhzs2lr5OXdBCNFWE5juucAAP/OHvBfnYAEJ 3xNaLAgBHUZpuHcsT1tOJwpJl1wsXLujN/K8tD5+4dV5GYxGHXPnaM28wfahoxYhFxGbfacOV 5XuXcVLyBTmfKVZ8gG7gklibEcbQDeioq5tDqjI9p0+/FXfMD1YbI7HKwAisj0Vu34MtMN+Zz a9y9izuMJ2UX+DSF5FxoWL3bTSE80Upvw+8ZpMQe25H3EJoyxTucJGkvKSO+aFxHpHR8xtadE J5AtEqSdl/2SU053ULkAyhzDtRCGzZ/JRtdJy9Sbd4PHUEMsJMQErzWl24UZSfYO3TQfUeUWC +mOUkDD+CLhkgZtFgJz7hdq4CXDCi9YGyACU4rHXzL9AJIhxCrQDTb4ILYYgNPu1lVdz/KBIJ zzYMJlfOxY17k2ypITZ/sGw+oLN96tpXUe+XLuwlO1pzLE4h9vrWbovQTir/azFwV/aSjZa7C JlKfmkCv+FQ03WhMLCZ7riKLULjC4JVGL6sjcf95BZAwEelWGNkZWNIF4sKTe8FuXSHQx4cYa 9lQ7uA/UNhXGOfwqJldFzXan1ZZgOVxVlIYhLkBBMl12jUR9rptc25KuCbkQGW4xAcp1fxhNc M9VdPHZFyYa+M4SWExhwjE40y31geht1iFjtGRcDa9ohXFrlxtnXUwxM1TkWMSJBH5qJXbWmh /wf7iT/dhsZRtAsX X-Original-Sender: src@andyf.de X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 212.227.17.24 is neither permitted nor denied by best guess record for domain of src@andyf.de) smtp.mailfrom=src@andyf.de 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:40109 Archived-At: Have a look at Peter Sommerlads work:=20 https://github.com/PeterSommerlad/ReverseAdapter #include "reverse.h" #include int main(){ using ::adapter::reverse; for(auto const &i : reverse({0,1,2,3,4,5})) { std::cout << i << '\n'; } } -- Andreas On 2018-08-29 00:28, Phil Bouchard wrote: > On Tuesday, August 28, 2018 at 5:17:47 PM UTC-4, Nevin ":-)" Liber > wrote: >=20 >> On Tue, Aug 28, 2018 at 4:06 PM Phil Bouchard >> wrote: >>=20 >>> Regarding the for loops with implicit iteration: >>>=20 >>> list cars; >>>=20 >>> for (auto const & i : cars) >>> =C2=A0 =C2=A0 ... >>>=20 >>> How about reverse iteration for consistency? >>>=20 >>> for (auto const & i !: cars) >>> =C2=A0 =C2=A0 ... >>>=20 >>> Or a better syntax. >>=20 >> reverse_view in The One Ranges Proposal p0896 [1]=C2=A0should address >> that. >=20 > Ok. If it can be an elegant one-liner like the following then it's all > good with me: >=20 > vector is {0,1,2,3,4};=C2=A0 > =C2=A0 > for (int i :=C2=A0reverse_view{is})=C2=A0 > =C2=A0 =C2=A0 cout << i << =E2=80=99 =E2=80=99; // prints: 4 3 2 1 0 >=20 > Thanks, > -Phil >=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 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/5e6ffea4-4c7= b-4da1-9602-bbd670ce1f8a%40isocpp.org > [2]. >=20 >=20 > Links: > ------ > [1] http://wg21.link/p0896 > [2] > https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/5e6ffea4-4c7= b-4da1-9602-bbd670ce1f8a%40isocpp.org?utm_medium=3Demail&utm_source=3Dfoote= r --=20 You received this message because you are subscribed to the Google Groups "= ISO C++ Standard - Future Proposals" group. 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