220 39150 article Path: news.gmane.org!.POSTED!not-for-mail From: mihailnajdenov@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Concept-defined placeholder type Date: Fri, 13 Jul 2018 09:07:13 -0700 (PDT) Lines: 1559 Approved: news@gmane.org Message-ID: References: <36f3bb9f-ca72-428c-b016-a3c035d657d8@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_130596_1289491458.1531498033531" X-Trace: blaine.gmane.org 1531497909 4678 195.159.176.226 (13 Jul 2018 16:05:09 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 13 Jul 2018 16:05:09 +0000 (UTC) Cc: zy@miator.net To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCUJ3A7GRAPRBMU4UPNAKGQEBY4YP4I@isocpp.org Fri Jul 13 18:05:05 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yw0-f198.google.com ([209.85.161.198]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fe0Z6-00016J-I2 for gclcip-std-proposals@m.gmane.org; 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Fri, 13 Jul 2018 09:07:15 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 2002:a25:4181:: with SMTP id o123-v6ls7112877yba.21.gmail; Fri, 13 Jul 2018 09:07:14 -0700 (PDT) X-Received: by 2002:a25:8486:: with SMTP id v6-v6mr659126ybk.3.1531498034046; Fri, 13 Jul 2018 09:07:14 -0700 (PDT) In-Reply-To: X-Original-Sender: MihailNajdenov@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:39150 Archived-At: ------=_Part_130596_1289491458.1531498033531 Content-Type: multipart/alternative; boundary="----=_Part_130597_2018154884.1531498033532" ------=_Part_130597_2018154884.1531498033532 Content-Type: text/plain; charset="UTF-8" On Friday, July 13, 2018 at 5:45:45 PM UTC+3, Hubert Tong wrote: > > On Fri, Jul 13, 2018 at 3:45 AM, > > wrote: > >> I am ok with Number auto >> >> And I hope it will be upgraded to Number T as it *dramatically* improves >> declarations as one sees a type like he always did, granted not a concrete >> one >> >> [](All Args&&... args) { f(std::forward(args)...); } >> >> *I will take that before ANY other form!* >> > It has been mentioned somewhere that we can and probably should pursue a > syntax to imbue auto with the ability to introduce a name for the type > deduced (or a name for the invented template parameter in deduction > contexts). So, the upgrade is not limited to Concept auto (and can be > pursued separately). > The way I see it, if we declare a blanket rule that a concept always introduces a typename (orthogonal to "class always introduces a type"), that tool is very powerful and actually makes auto *inferior*: func(Any Arg&& a) reads *better* then, func(auto&& a) *even if* we don't use the type! One might argue in template header it will be confusing, but that is speculation, because in practice the name of the variable should be lowercase and/or will have clearly non-typy name template template also template is *better* then template (and we have the type as a bonus) A great benefit is the fact one is *explicit* he takes ANYTHINIG which *might* not be good idea and one might reconsider and go and constrain the types. -- 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/eeae7fd0-92f0-488d-9a5f-face9091b562%40isocpp.org. ------=_Part_130597_2018154884.1531498033532 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Friday, July 13, 2018 at 5:45:45 PM UTC+3, Hube= rt Tong wrote:
On Fri, Jul 13, 2018 at 3:45 AM, <mihailn...@gmail.com> wrote:
I am ok with Number auto

And I hope it will be upgraded= to Number T as it dramatica= lly improves declarations as one sees a type like he always did, grante= d not a concrete one

[](All Args&&... args) { f(std::fo= rward<Args>(args)...); }

=
= I will ta= ke that before ANY other form!
It has been mentioned somewhere that we can and proba= bly should pursue a syntax to imbue auto with the ability to introduce a name for the type dedu= ced (or a name for the invented template parameter in deduction contexts). = So, the upgrade is not limited to Concept auto (and can be pursued separately).
=


The way I see it, if= we declare a blanket rule that a concept always introduces a typename (ort= hogonal to "class always introduces a type"),
that tool is= very powerful and actually makes auto inferior:

func(Any Arg&& a)

reads better then,=C2=A0

=
func(auto&& a)<= /span>
=
even if we don't use the type!
=

One might argue in template header it will be confusing, but that= is speculation, because in practice the name of the variable should be low= ercase and/or will have clearly non-typy name

template<N= umber Num N>
template<RandomNumberGenerato= r RNG rng>

also=C2=A0

template<Any Val val>
is better then=C2=A0
template<auto val>

(and we have the type as a bonus)

A great benefit is the fact one is explicit he = takes ANYTHINIG which might not be good idea and one might reconside= r and go and constrain the types.

--
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/eeae7fd0-92f0-488d-9a5f-face9091b562= %40isocpp.org.
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