220 13499 <3cc36209-3837-4b00-a976-123e01d25a72@isocpp.org> article Path: news.gmane.org!not-for-mail From: Tomasz Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Generalizing the equivalence of auto and template type deduction Date: Thu, 2 Oct 2014 02:29:23 -0700 (PDT) Lines: 103 Approved: news@gmane.org Message-ID: <3cc36209-3837-4b00-a976-123e01d25a72@isocpp.org> References: <0bf78c13-6ee2-4a9a-9de5-5ce2dc0e5a66@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_4566_65926435.1412242163136" X-Trace: ger.gmane.org 1412242175 27883 80.91.229.3 (2 Oct 2014 09:29:35 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 2 Oct 2014 09:29:35 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDNPVXXG6IGBB45VWSQQKGQECELOSJA@isocpp.org Thu Oct 02 11:29:26 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yk0-f197.google.com ([209.85.160.197]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XZchR-0005QA-Gp for gclcip-std-proposals@m.gmane.org; Thu, 02 Oct 2014 11:29:25 +0200 Original-Received: by mail-yk0-f197.google.com with SMTP id 20sf1017777yks.8 for ; Thu, 02 Oct 2014 02:29:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; 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 :content-type; bh=BIrdsft1I43L6fEq6TWPDXTNFHBelhFfuOTmbutyu/I=; b=iCkvz255jvFIWit2ZmRuPYd7Hx9gla8mQg1+xKBJm1/RqyOASlJuAgE4ozAPSgN8kH zUquxxdYQQmPhkQrpP+o8jmCtps3Z7pVqsm6lUusno/iZHuSBhP9pcqeaIxNt0wEt2sp x/jUWpnkkchn1ze/488t0DAzLloxvaJLyhIOWdfFfdWaZST2R8HBHt7GnJav19tfHD6b f6I0L+DqyxlDa2vqgVEVAszvOa8bkhcI23GvSPehW78mpm8EDDCYDJlVaV2J7is7aC3F ze9Rkfo1r8tfxrcBeFm4JzAKz9mnSyI7cX4kRWJTwwuT4BEoS1N6UTqu5eK1Cvr4R9HX fuiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; 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:list-post:list-help:list-archive :list-subscribe:list-unsubscribe:content-type; bh=BIrdsft1I43L6fEq6TWPDXTNFHBelhFfuOTmbutyu/I=; b=Ges8SrXlavKzOk0XHvrryrHmyxmejsMWsHkH5oMqYr3HcwKQ3Y1K/kIFAN8Smnj7RF SIh9JOo5q5BDshK9+g4MildFQDPU/rJ/KbJhPGrwFDTj0bpvr6VHydKt0teegIJulWFb RVvCZWISrYKIik/HMJqGZl8KBbQo++S5n7Ol3ddJnNl7ViYZw8/+ZAwD2XmySXVK30Hk sDZqrBvDFVq/lV1PCImpJ6jRuzMT+ntjeawc2Mu5/BCAZVKeB40hpdDcWC74eRd4vpDw ZelSNI66teYxaTFtZYrIs6GL4++yDqY1UjbDnFaU7pI80Bw5V2ZkqkX45NNCXtnFjL6q tTBw== X-Gm-Message-State: ALoCoQkpkA6KzRAqMR7CisfhOZrG8z9FYA7X9e/qNYhpfUknK5Z9QJfX0FEBCoq6M7jMmaLP1RBZ X-Received: by 10.52.232.37 with SMTP id tl5mr22208923vdc.4.1412242164182; Thu, 02 Oct 2014 02:29:24 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.140.109.195 with SMTP id l61ls694726qgf.75.gmail; Thu, 02 Oct 2014 02:29:23 -0700 (PDT) X-Received: by 10.140.27.166 with SMTP id 35mr497521qgx.5.1412242163567; Thu, 02 Oct 2014 02:29:23 -0700 (PDT) In-Reply-To: X-Original-Sender: tomaszkam@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:13499 Archived-At: ------=_Part_4566_65926435.1412242163136 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sorry, I misunderstood your point. I think with use of concepts as placeholders we can still require different= =20 type. Let assume that we have concept Different Type, could probably= =20 write: std::pair> f =3D..; but I would say that the programmer should specify types explicitly in that= =20 case. Also for the examples were pair used in the function: We=20 already have a longer notation that would allow us to a specify constrained= =20 case, so there is not need to cover that in shorthand notation. W dniu czwartek, 2 pa=C5=BAdziernika 2014 11:13:10 UTC+2 u=C5=BCytkownik Vi= lle=20 Voutilainen napisa=C5=82: > > On 2 October 2014 11:43, Tomasz > wrote:= =20 > > My proposal is that every use of placholder (today we have only auto,= =20 > but=20 > > concept name would be a possible extension) would introduce separate=20 > > typename, so:=20 > > std::pair p =3D f();=20 > >=20 > > Would use equivalent deduction as:=20 > > template=20 > > void foo(std::pair);=20 > > That's already how it works.=20 > --=20 ---=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. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposa= ls/. ------=_Part_4566_65926435.1412242163136 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Sorry, I misunderstood your point.

I think with use= of concepts as placeholders we can still require different type. Let assum= e that we have concept Different Type<A,B>, could probably write:
= std::pair<auto{T}, Different Type<T>> f =3D..;
but I would s= ay that the programmer should specify types explicitly in that case.
Also for the examples were pair<auto, auto> used in the function: We= already have a longer notation that would allow us to a specify constraine= d case, so there is not need to cover that in shorthand notation.

W = dniu czwartek, 2 pa=C5=BAdziernika 2014 11:13:10 UTC+2 u=C5=BCytkownik Vill= e Voutilainen napisa=C5=82:
On = 2 October 2014 11:43, Tomasz <toma.= ...@gmail.com> wrote:
> My proposal is that every use of placholder (today we have only au= to, but
> concept name would be a possible extension) would introduce separa= te
> typename, so:
> std::pair<auto, auto> p =3D f();
>
> Would use equivalent deduction as:
> template<typename T1, typename T2>
> void foo(std::pair<T1, T2>);

That's already how it works.

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