220 35827 article Path: news.gmane.org!.POSTED!not-for-mail From: Jake Arkinstall Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Output parameters Date: Sat, 9 Dec 2017 19:58:55 +0000 Lines: 68 Approved: news@gmane.org Message-ID: References: <1c1bb50b-2d59-4247-a158-158065fb1a9a@isocpp.org> <0c471d5c-b9b2-40f9-a2bf-908edbb1f272@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="001a11492a4238f19a055fedbb1a" X-Trace: blaine.gmane.org 1512849538 16354 195.159.176.226 (9 Dec 2017 19:58:58 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 9 Dec 2017 19:58:58 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDCZX3WUUQFRBAMBWHIQKGQEE5UUVMI@isocpp.org Sat Dec 09 20:58:54 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-oi0-f72.google.com ([209.85.218.72]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eNlGt-00043x-A7 for gclcip-std-proposals@m.gmane.org; Sat, 09 Dec 2017 20:58:51 +0100 Original-Received: by mail-oi0-f72.google.com with SMTP id u126sf6278447oif.23 for ; Sat, 09 Dec 2017 11:58:58 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1512849538; cv=pass; d=google.com; s=arc-20160816; b=wWU7qJCK0cR9+hXJN7OCWpmZbGXd4ngfDWtIwtRXQoBMfKPhmgSDTYikxhIXcECRG1 S8/bfCF0tJJ3GT1KebLK4omPdYUqi4bUzor6o1E+j7DzZYe4xQoMTrC0b0xnZ6cSNFc7 lWmhCVoV0DEWoNtoR6Xoxa559pJAtsymMWy9kJK6E/gxFgS1MbUhZawi/Rex0Xih+98v atakcz174nMeo789hTmtOnQpvtm9Ogkbd7MHWtmsmWBbnWanMfRwWKuQpR9siKU4oOjF p0034790ZDuAHljo9EtmcL3UVLW0UEe7TJ7OByN7l8EEyingptT0xAUq6noygA865icD PiGQ== 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:mime-version:arc-authentication-results :arc-message-signature:dkim-signature:arc-authentication-results; bh=Cp3QropBKh6fMHmg+yRatPnaprJ/FqKsL746sKVo/JQ=; b=Mt+LdsJ95hx2apzrFwf1XQK+LyO+UDgNNQDgas9RgriJm7mPx0I0uj1NHGILwQ39yB LzenqKA2nOwLUO5bPKxWQv5Ax8liJTKaJd8NlZTsmtF+bcV6lfG2EsoC9v3j8f6isaZm H7VUu+GmK4J++XpIFUK9/T83+++23BEqeEQGqU7QvndcBJ+/PxhcriD8ecTKoviTt898 qDsu52QCUqd7Yp1qVC4UqgcT89n/chn204AaSTYYup8qa9qPCGZjWCrTG9N21eEmZFeh 4Vx2PwUANBIv1k595LAQUtkRN9UjCFiPHFwrbthSfyQSqlc3cjvWDdy02q8GT8jexVjs t9fQ== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=M8yCkyAM; spf=pass (google.com: domain of jake.arkinstall@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=jake.arkinstall@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :x-original-sender:x-original-authentication-results:reply-to :precedence:mailing-list:list-id:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=Cp3QropBKh6fMHmg+yRatPnaprJ/FqKsL746sKVo/JQ=; b=ihOWwtAVtXXfO+8QSlwRBY5cp7d1QQBI6r8EHv2+DDeEF5vVjePU1mzqpufGDJAdGY 77XdA/lnAcyhw6UNmr+Diim1t/zQZXGgFTijqu33f4IU93N4WbH+dfpHxFNxayPAngMB D7rfR0YMc+fpWbw3jZjGA7qIoONXecEgVnGTlzNSKmq6bqHFSzBo6gnadpFx7ngLdoHo P5t9JpPZ2h0Ms6GfO9jjqwiy7cLfnlVLiCo52xMFmYe5/SSgP/A/rjrfP5wqV6dl0S7O tYdi425rl/GdLnm3y6btM7TWbk+glOq6zDgWi4YyTBYFYTljexA79RVLnN11qD9cUequ 4H3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version: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=Cp3QropBKh6fMHmg+yRatPnaprJ/FqKsL746sKVo/JQ=; b=PlJ0Ke9KCg/IkSB2wR8yJwzdBeBGViPFoWcnIQ4pXrmibpBXlWBoexBdwmvDWAwm+R KUaEKrFgnQZxDm9Xyb6FV6xzYF7kQ+s3WGJ8YwotbMGewQNC20cBdFNDQxexBpXDDtlf QdSXBUPwk7FkCmmfM2f73ts2ZiCofYSMLuMnSa8MQachanF1EmfB75giE3ovQvRgVw5+ DSArZdxHMu1Poowq0urH2CtqTtV+2NH1lyS/5xcjYxmV0AqwZcZZJ79Mn/FcCHhRcA+u +f1qY9MSSjyURMxN0Nnu9mtJtYweafVbb1lj3pV9p3M9y6HRUEEDeEW10e/bJazLz11i +Vxw== X-Gm-Message-State: AJaThX7AA5hXhb2CiOzjDqxLf4m9skGKNkL2dUgcSZDWvddv+cbfgjIl 9QzdMDaWtfvnkapBvbdmOcQWcQ== X-Google-Smtp-Source: AGs4zMa2ShKXOKZybS/lZvv/oKcEKJUGZI52klNlW+70XQGr1AqlxlBcqjk2VnURX7JQI7f7qu0/9A== X-Received: by 10.202.245.151 with SMTP id t145mr18351488oih.46.1512849538200; Sat, 09 Dec 2017 11:58:58 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.202.213.14 with SMTP id m14ls1042150oig.17.gmail; Sat, 09 Dec 2017 11:58:56 -0800 (PST) X-Received: by 10.157.21.84 with SMTP id z20mr31870019otz.117.1512849536954; Sat, 09 Dec 2017 11:58:56 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1512849536; cv=none; d=google.com; s=arc-20160816; b=xx+VjQ/iMjwFFw3dOrczb36R9Kx89zcYxfkIY2DcY/VEqRtPFhGZroWw4FXOyk4u4w bOSOJkNi+sgzeMWKKAfcU3775DewU6DLjtSiMNIUQOn1usAibbM1OEAl42DYY3pQ6wa+ nOHsmm1eTiJzpwegNDKc94MsGzaAj9AkDhpDFx4DllJwICspUQrQ5LbTkzElrVMdpXn6 /R1Nvkl20jgnHBzau2YZsFYk057qR8FTtpZ+6f3hTRJWLDEmFNYw25GnecF9kAJ3C8MQ 89pY8PvzcGU+pU4MPFkeTqNGzqwo8oe1tEvvd+j/VhN/Ll5RfWb5Q4AciGk3ifkQ/+QO +eiQ== 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:mime-version :dkim-signature:arc-authentication-results; bh=Me4CrKY+5ntMpVEMznX/2fkznQXbP4V/QgOodTyFBeA=; b=P8mxtzdyRyb2UE6btI++kwGIG/5z5LSk3mVIFyaMFNJHpoDgrckCmn0VAWPupLwI+r 5YlICM6zXj07TfAFjhWwqxqMbCaBUtNQ33cJzkPJsR+cMdwHsQ1YIVEiIVdNHhKI1Q+M 84bjUhTMiYEMsUCk1vX0I5TfV+jpnnoWMHK1NlpwCClW5nmY1Q2nLPlT5mK0z782Iuv0 QoxLuoRKzr484KfIMqfeW88UZBN8zqrQd012Fa51Y+JpFruZS10COHGtoLV7oNvyuY/F n+ZrtSc+/K2M+i5WD0xhK/j0LUckYL4IxiK/uhh4n86FDMetDU3VH3x8pZYHDY3pzax2 eSBA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=M8yCkyAM; spf=pass (google.com: domain of jake.arkinstall@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=jake.arkinstall@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=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 p52sor3957792ote.168.2017.12.09.11.58.56 for (Google Transport Security); Sat, 09 Dec 2017 11:58:56 -0800 (PST) Received-SPF: pass (google.com: domain of jake.arkinstall@gmail.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; X-Received: by 10.157.61.201 with SMTP id l67mr28800203otc.384.1512849536510; Sat, 09 Dec 2017 11:58:56 -0800 (PST) Original-Received: by 10.168.69.140 with HTTP; Sat, 9 Dec 2017 11:58:55 -0800 (PST) Original-Received: by 10.168.69.140 with HTTP; Sat, 9 Dec 2017 11:58:55 -0800 (PST) In-Reply-To: <0c471d5c-b9b2-40f9-a2bf-908edbb1f272@isocpp.org> X-Original-Sender: jake.arkinstall@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=M8yCkyAM; spf=pass (google.com: domain of jake.arkinstall@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=jake.arkinstall@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=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:35827 Archived-At: --001a11492a4238f19a055fedbb1a Content-Type: text/plain; charset="UTF-8" On 9 Dec 2017 19:36, "Nicol Bolas" wrote: functions should not have "strictly output parameters". I can understand taking input/output parameters (like a `vector` that you add data to), but there's no reason to have "*strictly* output parameters" in C++. I agree. Parameters that are strictly for output don't really fit into modern C++, or at least that is the impression I get. I certainly haven't seen it in quite some time. I also don't see why describing a parameter in a special way would be useful. If a function accepts a non-const reference, that is already glaring indication that the intention is to change the value. Is there any real difference between having a parameter that is designed purely to be modified without being read first? Not that I can think of, but I welcome anyone to correct me. -- 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/CAC%2B0CCOqP9YtXXQCz7ZAv-Lu%2BNhOVGH52Fnun1NsuJQ_yJvpmQ%40mail.gmail.com. --001a11492a4238f19a055fedbb1a Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On 9 Dec 2017 19:36, "Nicol Bolas&= quot; <jmckesson@gmail.com>= ; wrote:
= functions should not have "strictly output parameters". I can und= erstand taking input/output parameters (like a `vector` that you add data t= o), but there's no reason to have "strictly output paramete= rs" in C++.

=
I agree. Parameters that are strictly for output do= n't really fit into modern C++, or at least that is the impression I ge= t. I certainly haven't seen it in quite some time.

I also don't see why describing a parame= ter in a special way would be useful. If a function accepts a non-const ref= erence, that is already glaring indication that the intention is to change = the value. Is there any real difference between having a parameter that is = designed purely to be modified without being read first? Not that I can thi= nk of, but I welcome anyone to correct me.

--
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/CAC%2B0CCOqP9= YtXXQCz7ZAv-Lu%2BNhOVGH52Fnun1NsuJQ_yJvpmQ%40mail.gmail.com.
--001a11492a4238f19a055fedbb1a-- .