220 36903 article Path: news.gmane.org!.POSTED!not-for-mail From: Nevin Liber Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: String interpolation Date: Tue, 13 Feb 2018 11:32:00 -0600 Lines: 128 Approved: news@gmane.org Message-ID: References: <356d5835-f1bf-4699-94f5-0b2d3d0b9c0e@isocpp.org> <25CCF885-86AD-4D51-8F5C-C46376D34DE0@gmail.com> <4890431.TR9UepuQra@tjmaciei-mobl1> <1cdb6300-7397-46d7-bce9-62e6e8dac40b@isocpp.org> <4bce681e-e729-4124-9322-69291fdb6678@isocpp.org> <8e456af5-09c3-461d-8562-30df127e93af@isocpp.org> <28e80709-5ebb-44d2-b26d-22cafd681330@isocpp.org> <52b86f0a-b3b9-455f-9d4d-0f6b15192c90@isocpp.org> <1e9a5468-6efa-48a2-87ce-6bdb6d5c4e83@isocpp.org> <750ecf62-9637-40f4-8585-e3be2780fb46@isocpp.org> <5b5435db-772e-4c38-8867-f6fbc66d7cec@isocpp.org> <5c51d89a-54b6-490b-87f2-09ed263d8322@isocpp.org> <305b7669-0744-473e-9715-807b7e8051b6@isocpp.org> <0ceb2063-d7b6-4cb8-8c5c-c63aceb5b549@isocpp.org> <41b87b07-1a91-4bca-ba00-5734c09dbe77@isocpp.org> <1a7f714d-4a91-4a95-8da4-0c688d18c4c4@isocpp.org> <5f8efcc0-f4e9-4518-abe5-5fffeab55083@isocpp.org> <0e0876bb-7a44-45ff-ab9b-6443e78ea59c@isocpp.org> <3468ee0c-a44a-437a-a835-0156c623df2e@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="001a114e7102b1c02f05651b6185" X-Trace: blaine.gmane.org 1518543058 13649 195.159.176.226 (13 Feb 2018 17:30:58 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 13 Feb 2018 17:30:58 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCE35H5S6IDBBOWCRTKAKGQEPBY444Q@isocpp.org Tue Feb 13 18:30:54 2018 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 1elePe-0002Lo-8z for gclcip-std-proposals@m.gmane.org; Tue, 13 Feb 2018 18:30:38 +0100 Original-Received: by mail-ua0-f198.google.com with SMTP id f13sf13139452uad.2 for ; Tue, 13 Feb 2018 09:32:44 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1518543163; cv=pass; d=google.com; s=arc-20160816; b=QKBzVpnCfotdZZc3FobpKP2cEY9Zm+Q6N9bYISUh9jGeidYCydlrgYYdm/LCsRrmt6 q0OENuxPztxQRltttRlQXin+YUdQjvgO5H+aNfLUoGqMEd7oqCgiReesQC2juJRkKmQU ENZhIVNCYrCE05U03VUNU4efIvD6e/VSzbpENLVTWNfPP/sCBPUOTqsr5A+h9WzjsIOt 4PgHBwu/Il33HipcLgOnz4hx47O0YDpSvNwg34uayYnTFjqeszJ3w7eY6fx6nuDa3hE0 rHLolo0q6DRNpPyadHi70LgyWwU+dxXLk0yMAlgi3sdEoZ5TRDYVZUqykSvho4QXIRKh cPjA== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:reply-to:to:subject:message-id:date :from:references:in-reply-to:sender:mime-version :arc-authentication-results:arc-message-signature :arc-authentication-results; bh=3E5blvnGVDqR9YPLpDHTPvLLd1o1NxWdxk37o24+Aj8=; b=m2ngF4nevJW0W0bw6X4hKxRz1hNI8wYItHjcKBCW8+PQVr6BYgJq5xWgmR3MOZyGdG JSFXB/tpBQVVqkzebrMeQAwtdU26bkz85d0Gu6Lr5UbfUbcZR7/YQqswSG5Mx4oPX0GW uRUfYJlgpkLskgkc4Kdiqjjd03oS1YN3wxJDzrgendua0/nckl3zWI0N6IzwUprZ5lKl dcJQEES6uZN3BDerrWcUI/cFdHqQheiw2VZdhL59lP6Z2cjBq0eKAhlxGK5PwAm5zQtE xvRTYorNA1qh0LMkjLkXcWXIcHcalg3mO/AkeXFQcCENQsEsFcjbOveuAAEqZBymLd6N bj2Q== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=MqvY32oA; spf=pass (google.com: domain of nliber@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=nliber@gmail.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=3E5blvnGVDqR9YPLpDHTPvLLd1o1NxWdxk37o24+Aj8=; b=Ayb1LnX6eocr98bcFpaULlZ8OLc+xrnIelMfi77eDSA8wU86y4Q6ByoWXBqJ3OcwqO BJZj1xFRZfrVOnhpW8EtyarcL4Rk1PKBLq7uDayUMycV5UBlO5DmXVkRv6H22wJe8jZ+ bHoflszzIbXQGmHH3s9ffKhu5p1T8xrF+7PzL3oUUNIDRqIWFM1a5gsxq8yxag7az1mT EwwyGObAHU/QRfWayJ0gh1+7Yd1zzBwx3r3vPk7xnUSnh68iEwYdx1wGlte71u6m5OBc Holf82cwXAxP3uQsY47NNTg5ex8WgYjSMzruolFEKmo50uCRXtVWszGmvCi019f7mJj8 UIGw== X-Gm-Message-State: APf1xPBllzJFcV5vHzg5/NphsdJ83r0e8f4tH/veZrLH4JuvXjXvIRmY mAw2aG2HTBfqxO0vmzvapBI= X-Google-Smtp-Source: AH8x226BdP3LT7rcRgHpJouwVGXCH+OeASnxNd5HrM/L4G/DUmlf7zaPmlWHAvzSxvyyKf11Dy3kRQ== X-Received: by 10.176.82.196 with SMTP id w4mr909510uaw.50.1518543163854; Tue, 13 Feb 2018 09:32:43 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.31.168.77 with SMTP id r74ls2667711vke.17.gmail; Tue, 13 Feb 2018 09:32:41 -0800 (PST) X-Received: by 10.31.106.133 with SMTP id f127mr1881096vkc.94.1518543161813; Tue, 13 Feb 2018 09:32:41 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1518543161; cv=none; d=google.com; s=arc-20160816; b=uR67jbMnieETYR35r6PAdW+Ufuft/HspLKphmBADuj08i7UU00xUB/I8jWfOJHBGGV pguj0nQsM5K/KPRRms90huXTXJzezG7P5Ssu8ZyMsNR6CD9zrzfTUYFF69V/Msfh8Hip Jo2UsVjOJNjx5H5TWeOivoK50K47ZL4+DBKNc5FrY2V/XK/J9800Xs+UO1G096rkw9WS NYhkH7Xmku9sObSxWrJ8/K1lIHN8ed56z5keDVUisLrWojZSJJSNFutIHt4tz8Vk3WWB dEYIJMoTWbcn9YRMx8hMSMjyDKkG1fypgVvXosm4FtNabfb5hBXk4tEDRHzdrRDR85nc WNYQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=to:subject:message-id:date:from:references:in-reply-to:sender :mime-version:dkim-signature:arc-authentication-results; bh=9wLpRj6HXbTiamQ7FKCclzpNDvQIeZY7TrKpep+OupE=; b=lTMZrlhTsbbXrzAr9rpkOgr8adPBLijmXf+w9nOmfiyz8ui9VsRoQMo0IuzqSB2J2P PuGO55g6/wz4dORcwrRspDE3qS/r82KE3aGkdKnVPQkUUny1jGqYalUJzV/2C0iRk1nl Ma9229/PcaqXANbkTERiZ57rCfZM1Tze4ub2jqiIT3LoNoJEtw34mSWtw1gECr2zeYTI lAnJqfxJJglLKQrby+Q2fmqfzX0ip2qVJxu6wrF7LQKvB3Yw6p/ku0UEVucG6iYj52dc DZC8i9hVRjjn6UDjy3gpkEl1kO1c7RT4MlXfD7g2CinwmmE53nu4v5DoTENFLlhg2Ssv Hcng== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=MqvY32oA; spf=pass (google.com: domain of nliber@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=nliber@gmail.com Original-Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id h137sor1011533vkd.110.2018.02.13.09.32.41 for (Google Transport Security); Tue, 13 Feb 2018 09:32:41 -0800 (PST) Received-SPF: pass (google.com: domain of nliber@gmail.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; X-Received: by 10.31.205.131 with SMTP id d125mr1917591vkg.110.1518543161112; Tue, 13 Feb 2018 09:32:41 -0800 (PST) Original-Sender: nliber@gmail.com Original-Received: by 10.103.116.134 with HTTP; Tue, 13 Feb 2018 09:32:00 -0800 (PST) In-Reply-To: <3468ee0c-a44a-437a-a835-0156c623df2e@isocpp.org> X-Original-Sender: nevin@eviloverlord.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=MqvY32oA; spf=pass (google.com: domain of nliber@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=nliber@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:36903 Archived-At: --001a114e7102b1c02f05651b6185 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, Feb 13, 2018 at 11:18 AM, wrote: > > > Le mardi 13 f=C3=A9vrier 2018 17:35:49 UTC+1, Nicol Bolas a =C3=A9crit : >> >> Because it would never be called. Basically, what you'd need is this >> constructor: >> >> template >> string_view(const char s[N]); >> >> But you already have this constructor: >> >> string_view(const char *s); >> >> An array decays into a pointer. And since the pointer constructor is not >> a template, it is considered a better match than the array version. And >> therefore, any ltieral you pass will go through the pointer version rath= er >> than the array template. >> >> And it should be noted that this has nothing to do with being a literal. >> If you used a `const char[]` variable, it *still* would prefer the >> pointer version due to array->pointer conversion. So this is not a case = of >> "string literals are broken now". >> > > How can you say that preferring a lossy conversion over a lossless one is > not broken? (Here, we lose the length information) > Well, you have to make a choice: 1. What do you want to do with arrays that have embedded '\0's? 2. What do you want to do with arrays that aren't terminated with '\0'? 3. Given how easy it is to decay an array into a pointer, do you want different behavior between the two? Any choice you make for these will make some users unhappy. --=20 Nevin ":-)" Liber +1-847-691-1404 --=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. To view this discussion on the web visit https://groups.google.com/a/isocpp= ..org/d/msgid/std-proposals/CAGg_6%2BN91RBTk2z6DdyjL0KDzF041f64Z%2BHuCB1Wdvm= dJAak0Q%40mail.gmail.com. --001a114e7102b1c02f05651b6185 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On Tue, Feb 13, 2018 at 11:18 AM, <<= a href=3D"mailto:florian.csdt@gmail.com" target=3D"_blank">florian.csdt@gma= il.com> wrote:


Le mardi 13 f=C3=A9vrier 2018 17:35:49 UTC+1, Nicol Bolas a= =C3=A9crit=C2=A0:
=
Because it would never be called. Basically, what you'd need is th= is constructor:

<= span style=3D"color:#008">template<size_t N&g= t;
string_view(const char s[N]);

But = you already have this constructor:

string_view(const char *s);
<= br>An array decays into a pointer. And since the pointer constructor is not= a template, it is considered a better match than the array version. And th= erefore, any ltieral you pass will go through the pointer version rather th= an the array template.

And it should be noted that this has nothing = to do with being a literal. If you used a `const char[]` variable, it st= ill would prefer the pointer version due to array->pointer conversio= n. So this is not a case of "string literals are broken now".
=

How can you say th= at preferring a lossy conversion over a lossless one is not broken? (Here, = we lose the length information)

=
Well, you have to make a choice:

1.=C2=A0 Wha= t do you want to do with arrays that have embedded '\0's?
2.=C2=A0 What do you want to do with arrays that aren't terminated wit= h '\0'?
3.=C2=A0 Given how easy it is to decay an array i= nto a pointer, do you want different behavior between the two?
Any choice you make for these will make some users unhappy.
--
=C2=A0Nevin ":-)&qu= ot; Liber=C2=A0 <mailto:nevin@eviloverlord.com> =C2=A0+1-847-691-1404

--
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/CAGg_6%2BN91R= BTk2z6DdyjL0KDzF041f64Z%2BHuCB1WdvmdJAak0Q%40mail.gmail.com.
--001a114e7102b1c02f05651b6185-- .