220 29468 <0cc57751-f41a-4da2-88e7-a42eb61f57cd@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: "col3435 via ISO C++ Standard - Future Proposals" Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Allowing string literals to match `char...` packs in templates Date: Fri, 18 Nov 2016 08:30:26 -0800 (PST) Lines: 77 Approved: news@gmane.org Message-ID: <0cc57751-f41a-4da2-88e7-a42eb61f57cd@isocpp.org> References: <9de07b5f-f870-4a02-882f-54f9fdd12ffd@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_6956_1657314984.1479486626432" X-Trace: blaine.gmane.org 1479486631 23885 195.159.176.226 (18 Nov 2016 16:30:31 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 18 Nov 2016 16:30:31 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCS5LL55TMARBI6ZXTAQKGQEO3SXC3Y@isocpp.org Fri Nov 18 17:30:26 2016 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 1c7m3V-00058Z-TH for gclcip-std-proposals@m.gmane.org; Fri, 18 Nov 2016 17:30:26 +0100 Original-Received: by mail-ua0-f198.google.com with SMTP id 34sf167111320uac.6 for ; Fri, 18 Nov 2016 08:30:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to: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=HrcDhc/m2poTFZ3qpiiGcutQ5nK7+UZGiT064xcPZFc=; b=shWgVVcQx2jcuPFTMoU6E/Ujqg9KrlSExX71k319tVCXrP3r4J+hrn0+hXb/MPzQY+ cS6Cr1olaFYfznvgV9SABq5omMvvyJCdSAArNE3sgX8z6ysyISTHjKtATxIMSNR1xvBb 2Z2JkGnJ2T6b4rQV+LvzlqlXI2Nm+0GDBrxREhnx4NI5LK5mUsOddTyMSiB/vSnNE03f 5Ocz/5L38OecUVIDwij0YaRuE3Hp0MaonW/EgGMqdWqK58lkZpSL7oFJVQSrF7aMX8jc rvjVNV4t2AgVf4sZe19jONsnHB5AqqcdpXw5LbX3DoPhqqNeje5ia83h96bL//8u3Ip2 4atw== 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:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=HrcDhc/m2poTFZ3qpiiGcutQ5nK7+UZGiT064xcPZFc=; b=k0LowwkvyBpbu5IWDWhq5fl6cNPzkXXOlbPym22srIzsWlIE2O5j4PkmDLuTyVflth 9DNrX5iGUqwykw75l8RsulBhLSY5pyJgzFInkOLDT2vk1e49Ri+CMvICECldIxWxnitw 64ytKgDmjikQYM9iPXsDa13aOo4hgmgl2Wki7y0JrnfThCZ7FS3RX/J3J4i0rwE56KqW mxfjEBELGHsFBDrP+YDdJ6Gw5xDH+2dNLuPqj2xNk4QSxnjQbZ+p9egAdPeoxBXQpLyc hzYl1r8ouWOZ8SxNuB820N6WhPiMTJFBy4Q5cGDYratcwfCf0yPWlVeKJAjcFkPt8vEX Lb0g== X-Gm-Message-State: AKaTC02T/UYmKZYai/tnZWK2mNKSzQjKvkEHuLseOTLqVpeJIzLjjl/s7GX7lElifyqtZg== X-Received: by 10.31.130.129 with SMTP id e123mr67076vkd.29.1479486627741; Fri, 18 Nov 2016 08:30:27 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.26.102 with SMTP id u35ls7389349otu.4.gmail; Fri, 18 Nov 2016 08:30:26 -0800 (PST) X-Received: by 10.157.39.129 with SMTP id c1mr54442otb.15.1479486626957; Fri, 18 Nov 2016 08:30:26 -0800 (PST) In-Reply-To: X-Original-Sender: col3435@yahoo.co.uk X-Original-From: col3435@yahoo.co.uk 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:29468 Archived-At: ------=_Part_6956_1657314984.1479486626432 Content-Type: multipart/alternative; boundary="----=_Part_6957_126519399.1479486626432" ------=_Part_6957_126519399.1479486626432 Content-Type: text/plain; charset=UTF-8 How about allowing literal types as template arguments if they have defaulted == and != operators (and this condition also applies recursively to all of their members). It does look fairly likely that we will get default == in the language in the near future. Once we have that, it would provide a natural way to express which types are unproblematic for use as template arguments. This would be more than good enough to get us arrays of characters. On Thursday, 17 November 2016 05:28:26 UTC, Louis Dionne wrote: > > So on Saturday, we tried looking into passing arrays as template > arguments, but > that becomes messy because arrays are already supported, but they decay to > pointers so we'd need to support a new syntax. We then tried passing > std::array, > but doing this cleanly would require passing arbitrary literal types as > template > arguments, which is also non-trivial of a change. > -- 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/0cc57751-f41a-4da2-88e7-a42eb61f57cd%40isocpp.org. ------=_Part_6957_126519399.1479486626432 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
How about allowing literal types as template arguments if = they have
defaulted =3D=3D and !=3D operators (and this condition also = applies recursively
to all of their members). It does look fairly= likely that we will get default =3D=3D
in the language in the ne= ar future. Once we have that, it would provide
a natural way to e= xpress which types are unproblematic for use as
template argument= s.

This would be more than good enough to get us a= rrays of characters.

On Thursday, 17 November 2016 05:28:26 U= TC, Louis Dionne wrote:
So on Saturday, we tried looking into passing arrays as tem= plate arguments, but
that becomes messy because arrays are alread= y supported, but they decay to
pointers so we'd need to suppo= rt a new syntax. We then tried passing std::array,
but doing this= cleanly would require passing arbitrary literal types as template
arguments, which is also non-trivial of a change.

--
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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/0cc57751-f41a-4da2-88e7-a42eb61f57cd= %40isocpp.org.
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