220 36904 <50a06b7a-bd73-4064-8422-56946338cbd1@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: florian.csdt@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: String interpolation Date: Tue, 13 Feb 2018 09:51:15 -0800 (PST) Lines: 165 Approved: news@gmane.org Message-ID: <50a06b7a-bd73-4064-8422-56946338cbd1@isocpp.org> 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/mixed; boundary="----=_Part_12324_1271598919.1518544275650" X-Trace: blaine.gmane.org 1518544164 8436 195.159.176.226 (13 Feb 2018 17:49:24 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 13 Feb 2018 17:49:24 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBC26HM4V3MIRBFGLRTKAKGQE7CX6J4A@isocpp.org Tue Feb 13 18:49:20 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ua0-f200.google.com ([209.85.217.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1elehc-0001QX-Jk for gclcip-std-proposals@m.gmane.org; Tue, 13 Feb 2018 18:49:12 +0100 Original-Received: by mail-ua0-f200.google.com with SMTP id g9sf12823607ual.8 for ; Tue, 13 Feb 2018 09:51:18 -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 :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=ksQfVwg73iDt7R7Q+MXFUHV83xAoGx/9v7QgWxR/S24=; b=Wy9EpJ7gA/+9fU5RVWrlCHLr0MwePWsqcuKRXSiJv8mPhx+FJPbv1PmAA6mQmWJV9W uemPE//ZHbYp5vbGAWXZ3SWevY7ljvxErC42y5NARcKpNJfc4NaCUCiHCw+RoSVrU3Le VXonM6/FQKYU7rZmzZnaXYFIhz47uyOS20vCsFs37/J3UpRoGxdWLnTZi4GT9UMQVvub Xfran03lJpUztBvJQgZdDU/KzRewdcBJOSF2mTBUwEq+wsg81Evd8+zys0F9EKSqdQW7 N9kcsqm7y9lQEtqPqZiNOoyLwkWlVeOKTdW1iCGtv0+jJj2NO8ILyAwLSCrHedg+AnDz gMkg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to: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=ksQfVwg73iDt7R7Q+MXFUHV83xAoGx/9v7QgWxR/S24=; b=AcTaTSwfZzRkaTZfIYBRB13M12ulsn0bgy4AO85loAsHSL4ww3QsgfogLytk8LT2WE BynRt2VFN2i9N6Lr9wFtAssSxKOO4IW3J0wL9ksh50V3TLCv519Q6ZyEvq/JLJwk9hI+ +qJGmt6cywyQ9z+jmvJXtIy//Gz9Zc2AiaeG+C0Rhp3ITBrzEb5CcSGYEwGlCdSe5ZQh TON8eiYSUyAA/iNywEMYT5j5eyz/FdojIgjeg6bN6KV85teqY8eO6FzRPs4GX2QmAGP7 yhcpYcpeHLVxULEtWuUtTWWV2SRqBPKmXD5pIcq5fTLU95rRHTqYAOgkoBBUSbr6bTdv L18w== 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: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=ksQfVwg73iDt7R7Q+MXFUHV83xAoGx/9v7QgWxR/S24=; b=Ux9A77k6c0KtsLb8Y6ZS5gesi9r0uXvmOxYIjIk9gZbGzPXmt/whiGSpd9f/pEQRR8 4R8NLNzfVc+awvf/gfxcSL2IzrS7Onf5ReBa7C40yyr+L0SgStRR4A1eGzgLe8mxCNi5 QrLYRLTpEEqDtjePJHUdXRihsXDozF2tXOlEZFBjuiWK2un2SRzx96mT7hdRO163+vmP OVLUx30ChJmFztnuhqffIyHQa5MOfOFxg7PzbQp54T/1xQdYqIweoZKyt+WYo439Vfw7 VELrhcxvrmyNP4m0/Fuq5ipgk13s45fG8v9TiOFdUmtVBkMtfSu4pg2K2L1S37C1zvu6 TSGA== X-Gm-Message-State: APf1xPAAW21XothgFSBWOw5F1pwtHX7gb0Ig+oFUQNhMxhA1z+rFV8xj pCvmKgqLUgu/ccWoJoyS8soecQ== X-Google-Smtp-Source: AH8x225l52HkOgUtbZgBC3POXbGRdfJDxfRX9OBe8Gr3d30jycuBHlkNWJ1BqBiy7mNTW9Pitnx/Xw== X-Received: by 10.31.155.87 with SMTP id d84mr970121vke.121.1518544278164; Tue, 13 Feb 2018 09:51:18 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.31.95.142 with SMTP id t136ls9348563vkb.20.gmail; Tue, 13 Feb 2018 09:51:16 -0800 (PST) X-Received: by 10.31.185.13 with SMTP id j13mr89868vkf.8.1518544276115; Tue, 13 Feb 2018 09:51:16 -0800 (PST) In-Reply-To: X-Original-Sender: florian.csdt@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:36904 Archived-At: ------=_Part_12324_1271598919.1518544275650 Content-Type: multipart/alternative; boundary="----=_Part_12325_393170162.1518544275650" ------=_Part_12325_393170162.1518544275650 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Le mardi 13 f=C3=A9vrier 2018 18:32:44 UTC+1, Nevin ":-)" Liber a =C3=A9cri= t : > > On Tue, Feb 13, 2018 at 11:18 AM, >=20 > 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=20 >>> 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 no= t=20 >>> a template, it is considered a better match than the array version. And= =20 >>> therefore, any ltieral you pass will go through the pointer version rat= her=20 >>> than the array template. >>> >>> And it should be noted that this has nothing to do with being a literal= ..=20 >>> If you used a `const char[]` variable, it *still* would prefer the=20 >>> pointer version due to array->pointer conversion. So this is not a case= of=20 >>> "string literals are broken now". >>> >> >> How can you say that preferring a lossy conversion over a lossless one i= s=20 >> 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=20 > different behavior between the two? > > Any choice you make for these will make some users unhappy. > 4. string literals are not arrays and can have their own rules. Any choice we make for these will make some users unhappy. =20 > --=20 > Nevin ":-)" Liber >=20 > +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/50a06b7a-bd73-4064-8422-56946338cbd1%40isocpp.or= g. ------=_Part_12325_393170162.1518544275650 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


Le mardi 13 f=C3=A9vrier 2018 18:32:44 UTC+1, Nevi= n ":-)" Liber a =C3=A9crit=C2=A0:
On Tue, Feb 13, 2018 at 11:18 AM, <floria...@gmail.com> wrote:

Le mardi 13 f=C3=A9vrier 2018 17:35:49 UTC+1, Nicol Bolas a =C3=A9crit=C2= =A0:
Because i= t would never be called. Basically, what you'd need is this constructor= :

template<size_t N>
string_view(const char s[N]);

But you already ha= ve this constructor:

<= div>string_view(const= char <= /span>*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 ltier= al you pass will go through the pointer version rather than the array templ= ate.

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 pref= er 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 lo= ssy conversion over a lossless one is not broken? (Here, we lose the length= information)

Well, you hav= e to make a choice:

1.=C2=A0 What do you want to d= o with arrays that have embedded '\0's?
2.=C2=A0 What do = you want to do with arrays that aren't terminated with '\0'?
3.=C2=A0 Given how easy it is to decay an array into a pointer, do = you want different behavior between the two?

Any c= hoice you make for these will make some users unhappy.

4. string literals are not arrays and c= an have their own rules.

Any choice we make for th= ese will make some users unhappy.
=C2=A0
--
=C2=A0Nevin ":-)" Liber=C2=A0 &l= t;mailto:ne...@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/50a06b7a-bd73-4064-8422-56946338cbd1= %40isocpp.org.
------=_Part_12325_393170162.1518544275650-- ------=_Part_12324_1271598919.1518544275650-- .