220 33565 <03d0948e-506b-4e0b-b5e0-b255d3698cd5@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Nicol Bolas Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Add type alias that mirrors given type Date: Thu, 3 Aug 2017 06:54:29 -0700 (PDT) Lines: 100 Approved: news@gmane.org Message-ID: <03d0948e-506b-4e0b-b5e0-b255d3698cd5@isocpp.org> References: <20f365ce-2a24-4576-894f-923e7b9cd76e@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_5451_1861794337.1501768469980" X-Trace: blaine.gmane.org 1501768471 7218 195.159.176.226 (3 Aug 2017 13:54:31 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 3 Aug 2017 13:54:31 +0000 (UTC) Cc: antonio@perezexcelsior.com To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCEKFTV6ZUMBBFWWRTGAKGQEZZLPZFY@isocpp.org Thu Aug 03 15:54:27 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-it0-f72.google.com ([209.85.214.72]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ddGa1-0001YJ-RG for gclcip-std-proposals@m.gmane.org; Thu, 03 Aug 2017 15:54:25 +0200 Original-Received: by mail-it0-f72.google.com with SMTP id o19sf15264995ito.5 for ; Thu, 03 Aug 2017 06:54:32 -0700 (PDT) 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=NskTZ/w4HVWtoG4po3k9rzwGgc6bKnQooQ7jNW+G8SM=; b=g6TQ7qSd1BCOg7xa/is1qb8cL7f6EK7eBNzHxQbL50SHJUsTkmxJWmL/DK8Sj+//jI M+yEbnStYzGs8ooBCZM7T1P2m6u4r8LqjIdkVgjqFJwcjd+dKGMRw/q6VZY0KXMoHoHV jUESLyJJVZb+ard33j1o8mSlyjtvnkBRaYtlmGhzUiqXlA53FNpFaqJXx4KFR+cQ1U5h 4LjAVO8OaPLyRhKDF9mHzl4iCUv9s55XqFy2mJgiXY9C8aYrXEI4j5Zq9stljbRUCCKM zeDSfRMFy01Dn0mef/k5gPNTKqFyLTmCoSfl8si1kuC8dycsVE2v3dN87MGYGzsYItOz i4Zw== 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=NskTZ/w4HVWtoG4po3k9rzwGgc6bKnQooQ7jNW+G8SM=; b=tNXnXsEuoUhXr9+NWI1q4pq+rHNPH/1AW+tPhYbc/5XgE9qOGTZYz3yaJ+ZGAKXXqD yfKECAsy+YXYiViSO6CtJaiJFPu3xK/qE79Mzef9xikG9eSHjnuc6y7SCtKtBMEWzdA2 WXxV3ZAyBQcaKZAG3S4CGT4dVUlte9pgfNoRwyhNkmlH9nSCudJY6vDdzHoUtduZL0la 4UpHseofl4+ScQRXUj4SUX5KGziMeBMuGlLA0/wukyN1Z/YA/s/gDbIHrM1y17nlqckK TMhHqh05hQ3IAiZrXe98/416epTKow/n+3PLODkfmqhYNBLzpMnf0EQyl3yfe+vm2bW3 incg== 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=NskTZ/w4HVWtoG4po3k9rzwGgc6bKnQooQ7jNW+G8SM=; b=CAwQXFUddU1/8H2mEWXCcg+amYAj+SCy5WoGPf0aFGrvjFYlqZj2z7Lfm+Pw18vL2G MRxQ8KwG7JOqDWOBBCRXDXFspsV5emaxH5nRZcddM0icLGW7w/AEehDJxhUvuDanCEsq yiz9yDgZqv9kE4P3jxnEpwtK0KlHgy3urJfURIOQKxQvH3LI128Nwt1Q11Axuhedbt+y SejY2qxU+zRHDhHapODrj5iJlwrJ80xjj+c9Q/R2GjGqkJ1FlBumhcAba3ZMJLp6l954 rtlpsjkdL1sIJhZZcrO4J3E/PrOtsQR6Eha0nUkgg/kTEwG3OrNnbpvDX2CZ4V6YLvyH SbeQ== X-Gm-Message-State: AHYfb5ioIClYG4imLtA8h3U0Wf0Qxn2d3mBh6PeXiC+tuue+CUN0HvPE DE8PB8mbbYAzb6U4 X-Received: by 10.107.170.38 with SMTP id t38mr1074468ioe.107.1501768471713; Thu, 03 Aug 2017 06:54:31 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.107.128.165 with SMTP id k37ls1613065ioi.37.gmail; Thu, 03 Aug 2017 06:54:30 -0700 (PDT) X-Received: by 10.31.160.13 with SMTP id j13mr7486vke.25.1501768470386; Thu, 03 Aug 2017 06:54:30 -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:33565 Archived-At: ------=_Part_5451_1861794337.1501768469980 Content-Type: multipart/alternative; boundary="----=_Part_5452_2039268355.1501768469980" ------=_Part_5452_2039268355.1501768469980 Content-Type: text/plain; charset="UTF-8" On Thursday, August 3, 2017 at 9:35:36 AM UTC-4, Matthew Woehlke wrote: > > On 2017-08-02 15:27, Antonio Perez wrote: > > I propose that a type alias which simply returns the given type be added > to > > the standard library for the purpose of working with types whose syntax > is > > problematic. > > > > *What's the use for this?*As an example usage, here is a print function > > that prints an array of things: > > > template void print(std::typemirror& arr) > > Um... > > template > void print(T (&arr)[N]) > > ...? > > I don't see a motivating use case here... > I think the motivation here is that that syntax looks *terrible* and quite a few people have no idea how to type that. The type of the object `arr` references is `T[N]`, so why isn't it on the left where types go? Every time I have to write something like that, I have to look up how to do it properly. Granted, since I got hold of gsl::span, I haven't had need to take such a horrible type anymore. -- 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/03d0948e-506b-4e0b-b5e0-b255d3698cd5%40isocpp.org. ------=_Part_5452_2039268355.1501768469980 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On Thursday, August 3, 2017 at 9:35:36 AM UTC-4, Matthew W= oehlke wrote:
On 2017-08-02 15:= 27, Antonio Perez wrote:
> I propose that a type alias which simply returns the given type be= added to=20
> the standard library for the purpose of working with types whose s= yntax is=20
> problematic.
>=20
> *What's the use for this?*As an example usage, here is a print= function=20
> that prints an array of things:
> > template<class T, size_t n> void print(std::typemirror&= lt;T[n]>& arr)

Um...

=C2=A0 template <typename T, size_t N>
=C2=A0 void print(T (&arr)[N])

...?

I don't see a motivating use case here...

= I think the motivation here is that that syntax looks terrible and q= uite a few people have no idea how to type that. The type of the object `ar= r` references is `T[N]`, so why isn't it on the left where types go? Ev= ery time I have to write something like that, I have to look up how to do i= t properly.

Granted, since I got hold of gsl::span, I haven't ha= d need to take such a horrible type anymore.

--
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/03d0948e-506b-4e0b-b5e0-b255d3698cd5= %40isocpp.org.
------=_Part_5452_2039268355.1501768469980-- ------=_Part_5451_1861794337.1501768469980-- .