220 34275 <4b5d3a6b-dbbc-4685-9cd5-7eb02b92db63@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Nicol Bolas Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Idea: Extension of structured bindings to definition of structs Date: Sat, 2 Sep 2017 07:12:05 -0700 (PDT) Lines: 127 Approved: news@gmane.org Message-ID: <4b5d3a6b-dbbc-4685-9cd5-7eb02b92db63@isocpp.org> References: <59dcbbbc-c536-4b7b-9c88-0638fb0cd58a@technion.ac.il> <7b9bf263-d3ca-42bf-aed6-4c7606782a28@isocpp.org> <1762295.OciJaA9sdk@tjmaciei-mobl1> <74349bfe-bb5a-a2ce-4142-5d46103d1d9f@technion.ac.il> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_2188_1456321742.1504361525594" X-Trace: blaine.gmane.org 1504361552 28104 195.159.176.226 (2 Sep 2017 14:12:32 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 2 Sep 2017 14:12:32 +0000 (UTC) Cc: cppljevans@suddenlink.net To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCEKFTV6ZUMBBNXYVLGQKGQEO3APYCI@isocpp.org Sat Sep 02 16:12:18 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-vk0-f71.google.com ([209.85.213.71]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1do99U-0005qE-Q2 for gclcip-std-proposals@m.gmane.org; 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Sat, 02 Sep 2017 07:12:07 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.36.120.77 with SMTP id p74ls1236444itc.2.canary-gmail; Sat, 02 Sep 2017 07:12:06 -0700 (PDT) X-Received: by 10.31.150.150 with SMTP id y144mr104942vkd.29.1504361526085; Sat, 02 Sep 2017 07:12:06 -0700 (PDT) In-Reply-To: X-Original-Sender: jmckesson@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:34275 Archived-At: ------=_Part_2188_1456321742.1504361525594 Content-Type: multipart/alternative; boundary="----=_Part_2189_2126878340.1504361525595" ------=_Part_2189_2126878340.1504361525595 Content-Type: text/plain; charset="UTF-8" On Saturday, September 2, 2017 at 4:35:24 AM UTC-4, Larry Evans wrote: > > On 08/30/2017 10:16 AM, Nevin Liber wrote: > > On Wed, Aug 30, 2017 at 2:59 AM, Eyal Rozenberg > > > wrote: > > > >> You would be using an unnamed struct for the same reason you use an > >> "unnamed type" for non-struct variables with auto. We write: > >> > >> auto x = expr; > >> > > > > Even though you don't spell it out, that type already has a name. auto > > doesn't create a new type. > > > > You are proposing yet another syntax to create a new type. As for its > use, > > about the only thing you can do with it is pass it to a template > function > > (or equivalent). That use seems fairly marginal. You need much better > > usage examples for motivation. > > > Boost spirit has a macro, BOOST_FUSION_ADAPT_STRUCT, which maps a tuple > to a struct, as explained here: > > > http://ciere.com/cppnow15/x3_docs/spirit/tutorials/employee___parsing_into_structs.html > > What the OP is proposing *seems* to obviate the need for > BOOST_FUSION_ADAPT_STRUCT. > P0648 would do so far more effectively. And far more *directly*, without having to create a new type. -- 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/4b5d3a6b-dbbc-4685-9cd5-7eb02b92db63%40isocpp.org. ------=_Part_2189_2126878340.1504361525595 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On Saturday, September 2, 2017 at 4:35:24 AM UTC-4, Larry = Evans wrote:
On 08/30/2017 10:16 AM, Nevin Liber wrote:
> On Wed, Aug 30, 2017 at 2:59 AM, Eyal Rozenberg <eya...@technion.ac.il>
> wrote:
>=20
>> You would be using an unnamed struct for the same reason you u= se an
>> "unnamed type" for non-struct variables with auto. W= e write:
>>
>> =C2=A0 =C2=A0auto x =3D expr;
>>
>=20
> Even though you don't spell it out, that type already has a na= me. =C2=A0auto
> doesn't create a new type.
>=20
> You are proposing yet another syntax to create a new type. =C2=A0A= s for its use,
> about the only thing you can do with it is pass it to a template f= unction
> (or equivalent). =C2=A0That use seems fairly marginal. =C2=A0You n= eed much better
> usage examples for motivation.
>=20
Boost spirit has a macro, BOOST_FUSION_ADAPT_STRUCT, which maps a tuple
to a struct, as explained here:

http:= //ciere.com/cppnow15/x3_docs/spirit/tutorials/employee___parsing_= into_structs.html

What the OP is proposing *seems* to obviate the need for
BOOST_FUSION_ADAPT_STRUCT.

P06= 48 would do so far more effectively. And far more directly, without having to create a new type.

--
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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/4b5d3a6b-dbbc-4685-9cd5-7eb02b92db63= %40isocpp.org.
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