From -3568606016859805039 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,c42fc9ad8a4a8a45 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 2003-01-20 15:53:26 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!kibo.news.demon.net!mutlu.news.demon.net!demon!mail2news.demon.co.uk!devnull From: llewelly.@@xmission.dot.com (llewelly) Newsgroups: comp.std.c++ Subject: Re: Lookup for operators in expressions 13.3.1.2 Date: Mon, 20 Jan 2003 23:53:22 +0000 (UTC) Organization: The Illusory Sorting Algorithm Lines: 38 Approved: fjh@cs.mu.oz.au (Fergus Henderson , moderator of comp.std.c++) Message-ID: <86fzrnl8yj.fsf@Zorthluthik.foo> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: mail2news.demon.co.uk 1043106802 25919 10.0.0.1 (20 Jan 2003 23:53:22 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Mon, 20 Jan 2003 23:53:22 +0000 (UTC) X-Received: from mulga.cs.mu.oz.au ([128.250.1.22]) by news.demon.co.uk with esmtp (Exim 4.05) id 18aljE-0006js-00 for mail2news@news.news.demon.net; Mon, 20 Jan 2003 23:53:20 +0000 X-Received: by mulga.cs.mu.OZ.AU id KAA10389; Tue, 21 Jan 2003 10:52:43 +1100 (EST) X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Path: comp-std-cpp-robomod!not-for-mail X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) X-Delivered-To: std-c++@ncar.ucar.edu X-Newsgroups: comp.std.c++ X-NNTP-Posting-Date: Mon, 20 Jan 2003 23:06:53 +0000 (UTC) X-User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 X-Spam-Status: No, hits=-10.3 required=5.0 tests=EMAIL_ATTRIBUTION,NOSPAM_INC,QUOTED_EMAIL_TEXT,REFERENCES, SPAM_PHRASE_00_01,USER_AGENT version=2.41 Xref: archiver1.google.com comp.std.c++:17301 gp1@paradise.net.nz (Graeme Prentice) writes: > Regarding the expression a @ b where @ is an operator such as << and a > has type T1 > > 13.3.1.2 para 3 bullet 1 says > > If T1 is a class type, the set of member candidates is the result of the > qualified lookup of T1::operator@ (13.3.1.1.1); otherwise, the set of > member candidates is empty. > > Does this mean that the class definiiton of T1 has to be visible or does > it mean that if the lookup fails for whatever reason, the set of > candidates is empty. > > For example if you write cout << "hello"; does the class definition for > the type of cout have to be visible. 3.4.3.1/1 (Qualified name lookup, Class members): # If the nested-name-specifier of a qualified-id nomintates a class, # the name specified after the nested-name-specifier is looked up in # the scope of the class (10.2) ... [sniped] The paragraph then continutes to specify 3 exceptions, applying to destructors, conversion-type-ids, and template-ids, none of which seem relevant to your question. So combining 13.3.1.2/3 with 3.4.3.1/1, I think the operator will be looked up in the scope of the class, whether it is 'visible' or not. --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html ]