220 36026 <0f7bbb29-e28c-4600-a2f6-fba0a80fec3d@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: inkwizytoryankes@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Make aliased templates first class citizens Date: Tue, 19 Dec 2017 06:32:05 -0800 (PST) Lines: 231 Approved: news@gmane.org Message-ID: <0f7bbb29-e28c-4600-a2f6-fba0a80fec3d@isocpp.org> References: <8e4dd67b-e929-4f83-8f68-4a7ebd20a4e3@isocpp.org> <7eb526d4-c557-443c-a7d5-235dc8e44926@isocpp.org> <6d5434aa-a3bd-460f-bdbd-3db00772768a@isocpp.org> <90bc6ae9-54a4-4fe5-b4ee-a32db51ca820@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_7884_1189233143.1513693925186" X-Trace: blaine.gmane.org 1513693809 26624 195.159.176.226 (19 Dec 2017 14:30:09 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 19 Dec 2017 14:30:09 +0000 (UTC) Cc: adrian.hawryluk@gmail.com To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBDDLTAGNTIBBBZWF4TIQKGQELBP5VUQ@isocpp.org Tue Dec 19 15:30:05 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ua0-f198.google.com ([209.85.217.198]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eRIuD-0006j2-Ay for gclcip-std-proposals@m.gmane.org; Tue, 19 Dec 2017 15:30:05 +0100 Original-Received: by mail-ua0-f198.google.com with SMTP id j20sf11857018uag.4 for ; Tue, 19 Dec 2017 06:32:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc: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=q3YLHqGxmuEizjIUhJEvsLjEOO5t6Po+uS0r8jlDJKo=; b=jNVrKM8wdneKKP2YPlVyCza6bE+mNp7j6TOuKEc7T/aDSUhHSdoGhTKlmLGIwGNrUl qjw/uFLqKEY/l2uiikoR9cz2DZ4P2SfaTPMgP/tysUTrdPmpNQHJjxznDB8FZLXKrLSb a9/LtKqC3CqZ0rZa67rtQxQmQpM25WIXBVP7XhjHOrei0iLiQOBa6zEjsrKEILih+pTt LpeDmVA/Of1JC837aJKNYR1oDxyOXVqUWClSO2tYBfDU/kmwmarkk+Cv2+rfyvxDzImk DQdAueQHzSnRmq0Xj7XlTjgjdcPuchgiJ0oPHgCH7jt++8EDAAgTXHRHGbzZcACefxGy JESA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc: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=q3YLHqGxmuEizjIUhJEvsLjEOO5t6Po+uS0r8jlDJKo=; b=TA3Jb7cZd5GULGLF5Qj874sjy8lJfiCJQ+dLJcSogjOTPmm9vnleFKKk6KUQq3d95m 25HEvKbsWJiSx5XxVlp5fKw+XJkKeMZxyFdTdvsbXuOvXCarRSxSdxI9P8LK4gHF/HCH rNHgD6Gtbqe2aU7oI9v6LmrXQ5imWZF1XHe94xPjEE3QjdMLub5CqWzuGRN7eP9S+AvQ xplyD+Il6e1Y8Y5U11XqG+AVJyS3OXez9YhoyuW4991KNK+uBrj7yGIdZhmGzpVtXJxZ +pcBkqlRloVQ98HvpERzNZPGYpl+Cz2Z1Mk/3TiQXLzAO4QoFe1nnji/V2VAcxAoDGgU 8h4g== 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:cc: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=q3YLHqGxmuEizjIUhJEvsLjEOO5t6Po+uS0r8jlDJKo=; b=s7FrOJpoQFCGp+BMzdMqY5W6Urznr7T11wC2wNuaZb6LdpWiy91lH/wwQmkknT2gsW /DjdAlj+iSHGx64v6lXPoiC6txJjZ9bOIwa5dYOwRweJLVqqi+7m0z0WHynKR3yLJ8N3 2sqGicFo2oADHAsF4Ly68YpTEzZGWWkPUgq47A81JblQjXIG/eRmKYEYC6VpylJAAbG2 MCJXgAPn1aG3DnhO/ATI9O66maPPZ+2liXzlMkjj62eRplt8T+Oiff5P7HouoVf9m/L5 CmVhjV7zmw45DkhG79Vog73T63zPaT0qiEGGrDI8BiXjQ2XwRCtv9fY8wbtV8ednHprh f2bw== X-Gm-Message-State: AKGB3mI0cNCjK9ZTnDGDcH15tfgtLCTNQsFpuJ3L/rKn1J7jONyv8GlQ w4qrSh1WTmHtf92zvQOOEW6HGg== X-Google-Smtp-Source: ACJfBotQpmLOpE233o783Ib0MVY0C6q8lj33vsZ4XeyHqm5PrrVc1VKXU+i5itzdJ4tP56rPzYVuCA== X-Received: by 10.31.94.202 with SMTP id s193mr1521744vkb.77.1513693927566; Tue, 19 Dec 2017 06:32:07 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.31.171.19 with SMTP id u19ls389089vke.9.gmail; Tue, 19 Dec 2017 06:32:05 -0800 (PST) X-Received: by 10.31.96.72 with SMTP id u69mr336947vkb.11.1513693925730; Tue, 19 Dec 2017 06:32:05 -0800 (PST) In-Reply-To: X-Original-Sender: inkwizytoryankes@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:36026 Archived-At: ------=_Part_7884_1189233143.1513693925186 Content-Type: multipart/alternative; boundary="----=_Part_7885_1134339811.1513693925187" ------=_Part_7885_1134339811.1513693925187 Content-Type: text/plain; charset="UTF-8" On Tuesday, December 19, 2017 at 2:47:55 PM UTC+1, Jack Adrian Zappa wrote: > > On Monday, December 18, 2017 at 3:56:37 PM UTC-5, Marcin Jaczewski wrote: >> >> >> >> On Monday, December 18, 2017 at 6:28:12 AM UTC+1, adrian....@gmail.com >> wrote: >>> >>> On Sunday, December 17, 2017 at 8:18:29 PM UTC-5, Marcin Jaczewski wrote: >>>> >>>> >>>> Right now I see only one problem with this: >>>> template >>>> using B = typename A::template template temp<1><2>; >>>> //or >>>> template >>>> using C = template A::template temp<1>; //this return template not >>>> type, this could be problematic when C++20 remove options for different >>>> `using` >>>> //or >>>> template >>>> using D = template template A::temp; >>>> You will probably need something like this to allow proper handle of >>>> `<` and `>` by compiler in dependent context. >>>> >>> >>> I'm not exactly sure what you mean. So, these are potential ways to >>> tell the compiler what it should be seeing? temp is a binary >>> operator? What is A? Could you please give more context or explain in >>> more detail what you are attempting to say? >>> >> >> What is `temp`? This is good question that your proposal should answer >> because it's dependent name on template parameter `A`. If we implements >> your proposition how you will access it if it is in dependent context? >> Right now we have way to distinguish between objects, types and >> templates, now with your proposal we will need new way to support your >> first class aliases. >> > > Ah, sorry. Not sure how I misread that. If I understand the current > parsing of C++, I think your 1st one is most appropriate. Also, could you > expand on what you mean by your 2nd item being possibly problematic in > c++20? > Last one is similar in functionality to your declaration: template template template using B = typename A::template template temp; template using C = template template A::temp; One difference is that in my case we would not need what template parameters are needed for `temp` For 2nd I referring to http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0634r0.pdf now depending what syntax you will want use this proposal will or will not affect it. This it simply thing to consider when you are choosing syntax for this proposal. -- 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/0f7bbb29-e28c-4600-a2f6-fba0a80fec3d%40isocpp.org. ------=_Part_7885_1134339811.1513693925187 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Tuesday, December 19, 2017 at 2:47:55 PM UTC+1,= Jack Adrian Zappa wrote:
On Monday, December 18, 2017 at 3:56:37 PM UTC-5, Marcin Jaczew= ski wrote:


= On Monday, December 18, 2017 at 6:28:12 AM UTC+1, adrian....@gmail.com wrote:
On Sunday= , December 17, 2017 at 8:18:29 PM UTC-5, Marcin Jaczewski wrote:

Right now I see only one = problem with this:
template<typename A<= /span>>
= using B= =3D typename = A::temp= late te= mplate temp<1><2>;
//or
template<typename A>
using C =3D template A::template temp<1>; //this return tem= plate not type, this could be problematic when C++20 remove options for dif= ferent `using`
//or
template<typename A>
using D =3D template template A::temp;
=
You will probably need something like this to allow proper han= dle of `<` and `>` by compiler in dependent context.

I'm not exactly sure what you mean.=C2=A0=C2= =A0So, these are potential ways to tell the compiler what it should be seei= ng?=C2=A0 temp is a binary ope= rator?=C2=A0 What is A?=C2=A0 = Could you please give more context or explain in more detail what you are a= ttempting to say?

What is `temp`? This is good = question that your proposal should answer because it's dependent name o= n template parameter `A`. If we implements your proposition how you will ac= cess it if it is in dependent context?
Right now we have way to distinguish between objects, types and templa= tes, now with your proposal we will need new way to support your first clas= s aliases.


--
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/0f7bbb29-e28c-4600-a2f6-fba0a80fec3d= %40isocpp.org.
------=_Part_7885_1134339811.1513693925187-- ------=_Part_7884_1189233143.1513693925186-- .