220 4797 article Path: news.gmane.org!not-for-mail From: Richard Smith Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Changing lambda scope Date: Sun, 2 Jun 2013 15:49:26 -0700 Lines: 142 Approved: news@gmane.org Message-ID: References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=089e013cc328fd9c2004de33a845 X-Trace: ger.gmane.org 1370213371 31776 80.91.229.3 (2 Jun 2013 22:49:31 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 2 Jun 2013 22:49:31 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDVNBJG4YAIBB54XV6GQKGQED25R3SA@isocpp.org Mon Jun 03 00:49:29 2013 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-vb0-f69.google.com ([209.85.212.69]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1UjH5d-0007zq-1p for gclcip-std-proposals@m.gmane.org; Mon, 03 Jun 2013 00:49:29 +0200 Original-Received: by mail-vb0-f69.google.com with SMTP id p13sf4593184vbe.4 for ; Sun, 02 Jun 2013 15:49:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-beenthere:mime-version:sender:in-reply-to:references:date :message-id:subject:from:to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-google-group-id:list-post:list-help:list-archive :list-subscribe:list-unsubscribe:content-type; bh=A9/+tiZQxeTdP/eIsBY3HobOjI2Yw7d1QUwjDlClZ2s=; b=lrKY/UnHpiNbjh8aV7cF9gDpa9WbgOsw/Bn5wK6uQm1lRjTCZ3OKKJlhDwQHbeq6s6 leHAQyzgXdsc/xk8mb/VvWPWXQ4Xz9XJtyD+eOVWiEjU8mxZGr0aSwe973U5eq2/vCWX sgVttOsDAV49noTe0zoTe1Qp9mAZiookHqyUfmA/21X/xNq6HmFxts6KCzSNWlGgP/Pl JFlYUPopIjKbOnsOMjGM+rUhX3zMe8VG6OzBTzP1I/uBdhmK989Dnj4eHLgERS18bk3u hb88VUNnVLuNySa6CFN2GsiG7qQrVc4ZJsO0c14iBNytYrd8jTRB7CNXcBvlYU26ScYN mTdA== X-Received: by 10.224.3.131 with SMTP id 3mr12547581qan.5.1370213368021; Sun, 02 Jun 2013 15:49:28 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.49.48.4 with SMTP id h4ls1832602qen.50.gmail; Sun, 02 Jun 2013 15:49:27 -0700 (PDT) X-Received: by 10.220.191.129 with SMTP id dm1mr16062418vcb.54.1370213366968; Sun, 02 Jun 2013 15:49:26 -0700 (PDT) Original-Received: from mail-ve0-x236.google.com (mail-ve0-x236.google.com [2607:f8b0:400c:c01::236]) by mx.google.com with ESMTPS id iz8si34189671vdb.97.2013.06.02.15.49.26 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 02 Jun 2013 15:49:26 -0700 (PDT) Received-SPF: pass (google.com: domain of metafoo@gmail.com designates 2607:f8b0:400c:c01::236 as permitted sender) client-ip=2607:f8b0:400c:c01::236; Original-Received: by mail-ve0-f182.google.com with SMTP id ox1so2382306veb.13 for ; Sun, 02 Jun 2013 15:49:26 -0700 (PDT) X-Received: by 10.58.45.71 with SMTP id k7mr16314969vem.0.1370213366731; Sun, 02 Jun 2013 15:49:26 -0700 (PDT) Original-Sender: metafoo@gmail.com Original-Received: by 10.58.246.226 with HTTP; Sun, 2 Jun 2013 15:49:26 -0700 (PDT) In-Reply-To: X-Original-Sender: richard@metafoo.co.uk X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of metafoo@gmail.com designates 2607:f8b0:400c:c01::236 as permitted sender) smtp.mail=metafoo@gmail.com; dkim=pass header.i=@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:4797 Archived-At: --089e013cc328fd9c2004de33a845 Content-Type: text/plain; charset=ISO-8859-1 On Sun, Jun 2, 2013 at 11:12 AM, Mikhail Semenov < mikhailsemenov1957@gmail.com> wrote: > And the following code works. I think auto may be the problem. >> > #include > #include > bool ok = true; > namespace range > { > template auto operator|(L l, R r) // -> int > { > return l(ok)+r(ok); > } > template auto map(T t) //-> std::function > { > return [=](bool range) -> int > { > if (range) return t.i; > return 0; > }; > } > } > struct A > { > int i; > A(int i1):i(i1) {} > }; > > int main() > { > A a1(5); > A a2(6); > int k = > range::map(a1) > | range::map(a2); > std::cout << k << std::endl; // 11 > ok = false; > > k = > range::map(a1) > | range::map(a2); > std::cout << k << std::endl; // 0 > > } > This does not compile in Clang: :31:9: error: invalid operands to binary expression (':12:16>' and ':12:16>') | range::map(a2); ^ ~~~~~~~~~~~~~~ :37:9: error: invalid operands to binary expression (':12:16>' and ':12:16>') | range::map(a2); ^ ~~~~~~~~~~~~~~ It appears that g++ includes the enclosing namespaces as associated namespaces for local classes, contrary to the current rules in the standard. -- --- 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. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/?hl=en. --089e013cc328fd9c2004de33a845 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Sun, Jun 2, 2013 at 11:12 AM, Mikhail Semenov <mikhailsemeno= v1957@gmail.com> wrote:
And the following code works. I think auto may be the= problem.
#include <iostrea= m>
#include <functional>
bool ok =3D true;
namespace range
{
=A0=A0=A0 tem= plate<typename R, typename L> auto operator|(L l, R r) // -> int =A0=A0=A0 {
=A0=A0=A0=A0=A0=A0=A0=A0 return l(ok)+r(ok);=A0=A0=A0=A0=A0= =A0=A0
=A0=A0=A0 }
=A0=A0=A0 template<typename = T> auto map(T t) //-> std::function<int(bool)>
=A0=A0=A0 {
=A0=A0=A0=A0=A0=A0=A0 return [=3D](bool range) -&= gt; int
=A0=A0=A0=A0=A0=A0=A0 {
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 if (range) ret= urn t.i;
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 return 0;
=A0=A0=A0=A0=A0= =A0=A0 };
=A0=A0=A0 }
}
struct A
{
=A0=A0 int i;
=A0=A0 A= (int i1):i(i1) {}
};

int main= ()
{=A0=A0=A0
=A0=A0=A0 A a1(5);
=A0=A0=A0 A a= 2(6);
=A0=A0=A0 int k =3D
=A0=A0=A0=A0=A0=A0=A0 range::map(a1)<= br>=A0=A0=A0=A0=A0=A0=A0 | range::map(a2);
=A0=A0=A0 std::cout << = k << std::endl;=A0 // 11=A0=A0=A0=A0=A0
=A0=A0=A0 ok =3D false;
=A0=A0=A0
=A0=A0=A0 k =3D
=A0=A0=A0=A0=A0= =A0=A0 range::map(a1)
=A0=A0=A0=A0=A0=A0=A0 | range::map(a2);
=A0=A0= =A0 std::cout << k << std::endl;=A0 // 0=A0=A0=A0=A0=A0
=A0= =A0=A0
}

This does not com= pile in Clang:

<stdin>:31:9: error: invalid operands to bin= ary expression ('<lambda at <stdin>:12:16>' and '&l= t;lambda at <stdin>:12:16>')
=A0 =A0 =A0 =A0 | range= ::map(a2);
=A0 =A0 =A0 =A0 ^ ~~~~~~~~~~~~~~
<stdin>:37:9: error: = invalid operands to binary expression ('<lambda at <stdin>:12:= 16>' and '<lambda at <stdin>:12:16>')
= =A0 =A0 =A0 =A0 | range::map(a2);
=A0 =A0 =A0 =A0 ^ ~~~~~~~~~~~~~~

It app= ears that g++ includes the enclosing namespaces as associated namespaces fo= r local classes, contrary to the current rules in the standard.

--
 
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