220 28532 article Path: news.gmane.org!.POSTED!not-for-mail From: Greg Marr Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: A plea to reconsider adding Structured Bindings to language Date: Wed, 5 Oct 2016 07:20:02 -0700 (PDT) Lines: 122 Approved: news@gmane.org Message-ID: References: <201610051238.17863.marc.mutz@kdab.com> <201610051300.02280.marc.mutz@kdab.com> <201610051411.30312.marc.mutz@kdab.com> <073a7698-1388-4858-b6fa-b2b62a4fb6f1@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_4423_380988592.1475677202981" X-Trace: blaine.gmane.org 1475677218 15249 195.159.176.226 (5 Oct 2016 14:20:18 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 5 Oct 2016 14:20:18 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBDEZH3XFPIIJHGGUX4CRUBFNOX3PY@isocpp.org Wed Oct 05 16:20:14 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ua0-f199.google.com ([209.85.217.199]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1brn3I-0002wJ-LI for gclcip-std-proposals@m.gmane.org; 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Wed, 05 Oct 2016 07:20:10 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.36.122.12 with SMTP id a12ls4468830itc.22.canary; Wed, 05 Oct 2016 07:20:03 -0700 (PDT) X-Received: by 10.36.71.141 with SMTP id t135mr693622itb.10.1475677203602; Wed, 05 Oct 2016 07:20:03 -0700 (PDT) In-Reply-To: X-Original-Sender: gregmmarr@gmail.com 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:28532 Archived-At: ------=_Part_4423_380988592.1475677202981 Content-Type: multipart/alternative; boundary="----=_Part_4424_921199171.1475677202981" ------=_Part_4424_921199171.1475677202981 Content-Type: text/plain; charset=UTF-8 On Wednesday, October 5, 2016 at 10:07:29 AM UTC-4, Ville Voutilainen wrote: > > On 5 October 2016 at 16:49, Greg Marr > > wrote: > > On Wednesday, October 5, 2016 at 8:09:43 AM UTC-4, Marc Mutz wrote: > >> > >> On Wednesday 05 October 2016 13:40:20 Domen Vrankar wrote: > >> > So you're saying that returning a structure with error status and > result > >> > or > >> > multiple results of which you only need one or two (reason being for > eg. > >> > cheaper to return all at once - due to for e.g. web service call or > >> > complex > >> > processing - than request one by one on need to basis) you would > still > >> > prefer dragging the entire structure around giving the feeling that > your > >> > code has more dependencies than it actually does? > >> > >> One of us is not underatanding SB correctly, or I don't understand you. > SB > >> stores the whole struct, too, it just defines local aliases to the > member > >> of > >> the struct (or tuple, or pair, or ...). > > > > > > Only if you say that you want references, using "auto &" or "auto &&". > If > > you use "auto", you just get copies. > > You get a copy of the whole struct, not copies of individual bindings. > That's not what's described in the paper. Has it changed since https://isocpp.org/files/papers/p0217r0.html ? The binding results in individual variables, and if they're copies of the values from the struct, there is no reason to keep the original struct around. -- 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/bdc55144-9d72-4661-958c-3582a535b579%40isocpp.org. ------=_Part_4424_921199171.1475677202981 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On Wednesday, October 5, 2016 at 10:07:29 AM UTC-4, Ville = Voutilainen wrote:
On 5 October= 2016 at 16:49, Greg Marr <greg...@gmail.com> wrote:
> On Wednesday, October 5, 2016 at 8:09:43 AM UTC-4, Marc Mutz wrote= :
>>
>> On Wednesday 05 October 2016 13:40:20 Domen Vrankar wrote:
>> > So you're saying that returning a structure with erro= r status and result
>> > or
>> > multiple results of which you only need one or two (reaso= n being for eg.
>> > cheaper to return all at once - due to for e.g. web servi= ce call or
>> > complex
>> > processing - than request one by one on need to basis) yo= u would still
>> > prefer dragging the entire structure around giving the fe= eling that your
>> > code has more dependencies than it actually does?
>>
>> One of us is not underatanding SB correctly, or I don't un= derstand you. SB
>> stores the whole struct, too, it just defines local aliases to= the member
>> of
>> the struct (or tuple, or pair, or ...).
>
>
> Only if you say that you want references, using "auto &&q= uot; or "auto &&". =C2=A0If
> you use "auto", you just get copies.

You get a copy of the whole struct, not copies of individual bindin= gs.

That's not what's described in= the paper. =C2=A0Has it changed since=C2=A0https://isocpp.org/files/papers= /p0217r0.html ?
The binding results in individual variables, and = if they're copies of the values from the struct, there is no reason to = keep the original struct around.

--
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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/bdc55144-9d72-4661-958c-3582a535b579= %40isocpp.org.
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