220 40085 <5e6ffea4-4c7b-4da1-9602-bbd670ce1f8a@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Phil Bouchard Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: for loops w/ reverse iteration Date: Tue, 28 Aug 2018 15:28:49 -0700 (PDT) Lines: 119 Approved: news@gmane.org Message-ID: <5e6ffea4-4c7b-4da1-9602-bbd670ce1f8a@isocpp.org> References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_1741_281447288.1535495329880" X-Trace: blaine.gmane.org 1535495205 7938 195.159.176.226 (28 Aug 2018 22:26:45 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 28 Aug 2018 22:26:45 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCAYTFXFZMBBBIUZS7OAKGQE7YTE54I@isocpp.org Wed Aug 29 00:26:41 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yw1-f72.google.com ([209.85.161.72]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fumRd-0001xl-NY for gclcip-std-proposals@m.gmane.org; Wed, 29 Aug 2018 00:26:41 +0200 Original-Received: by mail-yw1-f72.google.com with SMTP id t10-v6sf1445984ywc.7 for ; Tue, 28 Aug 2018 15:28:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=foOq3hrsT1BfqitCGmBwalVUhx7nS58ihem5BQQOdqM=; b=R7iUYq2RaBK8mutbqPF5RIso2JEsV9J+GqnbxnXN3IUawaV3h9JLDAZUyx//uAgUan iFuynpuYXEokJKvKlpRj6LkGHtqzU1oRHHviwZ5HqhQYo/bzhZyWejYPNFO6hObwle0q 4hXi7qTs8nou6HZXRUleoe6zYrJMhXYiyXvpLfigS/4FJY8/sar9sV2PC1IZzyLo/xFY //i4i9E7Ws7MbUNN4I2AGEUq6v1KJrj9rWaY4f3IEeAolSLqx5r/FA0nUIfrOa0qc1Ee VyZBp8wuFsknCZ6kp4qYmh3/lceQ2bCCVZKreWHYvBcOLqXvfBt7XjOLUXyxQyZ2fmye D2zA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=foOq3hrsT1BfqitCGmBwalVUhx7nS58ihem5BQQOdqM=; b=fayrMMzVgpT8rJa2TM9rWU7e/wopMCrDhNNUjLeEfMu8b0iXuKav6HzGZ//XdPV3qz iX5DAzhW4eWie9rI4YyaE9A/dM41iQcHE5CY65d281yj0XdExqTKfUk8tWFkerK3rpsP GbuDHV2jYkBtsA2/xLPCBt2vIFJY7/mJe4di57zE8rtmPA37QqWDM9icv+UmL+PCsL3Y cRRTxQ4oK85OAk8jcGZrKRRRwMRXBXRm4k3HOZufY3iW/vXUJzYZqFF8DyWXiNVpuiB8 mxhOQaU5aN6m6aAJcdBh5HtGGO9YzRk6bzKWR6PVrIBMWrCU6KJ2X6SY7FD0T1LPWN0z bNTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:x-original-sender:reply-to:precedence :mailing-list:list-id:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=foOq3hrsT1BfqitCGmBwalVUhx7nS58ihem5BQQOdqM=; b=JR06RsK4b/wp0ZAZdQYH1XoCqehOKKH9DfRM8jHXvVTrxyCAXL+g7jVZQwhsKY5D0N lmcRTm2hs/OzvmsnAkLxj3fc8GRlpPHzwlCae+3+TK5daglBEHuRwfzyCUx482TnnY2l +EUyMqje+OTsPmmjmDjeKixJQ3D4rsityGcjWqMfvBVnds7PlkdJTyfoJi0fkCokwzaQ XOkpoZjGtAeZBz5qC6bzvRbW4IYITWcY1Jt1VuhARlTVgifn/apf5JL8Ldv5/woZvuI9 roIC8mMbSSAIImZM5DGLOkMa8jUDpe840eYpwChUAVl3nUcA2R0mBuyYCdWnMPGaomgp +Hjw== X-Gm-Message-State: APzg51DGyYbDOdJsjctptZrU3HzeNVVYWNlaC/9fZZ+5rO8rSl6wBvCn u8aEzD8r6UMp7W1Ty0yt0zzqVA== X-Google-Smtp-Source: ANB0VdYB3AvLEIXicBS2wOFaIr/cMm1qmiRKFEeLKh5bPw/d5Vw3bImYW/E0ONax5lHEmluOqPIqYg== X-Received: by 2002:a0d:c386:: with SMTP id f128-v6mr1095192ywd.45.1535495331735; Tue, 28 Aug 2018 15:28:51 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 2002:a81:a28c:: with SMTP id z134-v6ls365083ywg.28.gmail; Tue, 28 Aug 2018 15:28:50 -0700 (PDT) X-Received: by 2002:a81:78c6:: with SMTP id t189-v6mr40633ywc.7.1535495330466; Tue, 28 Aug 2018 15:28:50 -0700 (PDT) In-Reply-To: X-Original-Sender: philippeb8@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:40085 Archived-At: ------=_Part_1741_281447288.1535495329880 Content-Type: multipart/alternative; boundary="----=_Part_1742_459365959.1535495329880" ------=_Part_1742_459365959.1535495329880 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tuesday, August 28, 2018 at 5:17:47 PM UTC-4, Nevin ":-)" Liber wrote: > > On Tue, Aug 28, 2018 at 4:06 PM Phil Bouchard > wrote: > >> Regarding the for loops with implicit iteration: >> >> list cars; >> >> for (auto const & i : cars) >> ... >> >> How about reverse iteration for consistency? >> >> for (auto const & i !: cars) >> ... >> >> Or a better syntax. > > > reverse_view in The One Ranges Proposal p0896 sh= ould=20 > address that. > > Ok. If it can be an elegant one-liner like the following then it's all good= =20 with me: vector is {0,1,2,3,4};=20 =20 for (int i : reverse_view{is})=20 cout << i << =E2=80=99 =E2=80=99; // prints: 4 3 2 1 0 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 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/5e6ffea4-4c7b-4da1-9602-bbd670ce1f8a%40isocpp.or= g. ------=_Part_1742_459365959.1535495329880 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Tuesday, August 28, 2018 at 5:17:47 PM UTC-4, N= evin ":-)" Liber wrote:
On Tue, Aug 28, 2018 at 4:06 PM Phil Bouchard <phili...@g= mail.com> wrote:
Regarding the for loops with implicit iteration:

list<string> cars;

for (auto const & i : cars)
=C2=A0 =C2=A0 ...

How about reverse iteration for consistency?

for (auto const & i !: cars)
=C2=A0 =C2=A0 ...

Or a better syntax.

reverse_view in The One= Ranges Proposal p= 0896=C2=A0should address that.


Ok. If it can be an elegant one-liner like the following = then it's all good with me:

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
=

Thanks,
-Phil

--
You received this message because you are subscribed to the Google Groups &= quot;ISO C++ Standard - Future Proposals" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposa= ls+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/5e6ffea4-4c7b-4da1-9602-bbd670ce1f8a= %40isocpp.org.
------=_Part_1742_459365959.1535495329880-- ------=_Part_1741_281447288.1535495329880-- .