From 8016988212333266783 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,924f354765fe932a X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 2002-05-22 13:17:02 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!bloom-beacon.mit.edu!nycmny1-snh1.gtei.net!news.gtei.net!newsfeed.mathworks.com!kibo.news.demon.net!news.demon.co.uk!demon!mail2news.demon.co.uk!not-for-mail From: John Nagle Newsgroups: comp.std.c++ Subject: Re: constructor calls in vectors Date: Wed, 22 May 2002 20:16:48 GMT Organization: Prodigy Internet http://www.prodigy.com Approved: Fergus Henderson , moderator of comp.std.c++ Message-ID: <3CEAF4CA.20200@animats.com> References: <3CE562E8.8050403@acm.org> <86r8k4e1ec.fsf@alex.gabi-soft.de> X-Trace: mail2news.demon.co.uk 1022098612 mail2news:9045 mail2news mail2news.demon.co.uk X-Complaints-To: abuse@demon.net X-Mail2News-Path: news.demon.net!mulga.cs.mu.oz.au X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.4) Gecko/20011128 Netscape6/6.2.1 X-Accept-Language: en-us MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit NNTP-Posting-Date: Tue, 21 May 2002 21:09:03 EDT X-UserInfo1: O@YORZSDTBSUCFH[OZK@_TDAYZOZ@GXOXZYT]UEK@YUDUWYAKVUOPCW[ML\JXUCKVFDYZKBMSFX^OMSAFNTINTDDMVW[X\THOPXZRVOCJTUTPC\_JSBVX\KAOTBAJBVMZTYAKMNLDI_MFDSSOLXINH__FS^\WQGHGI^C@E[A_CF\AQLDQ\BTMPLDFNVUQ_VM Lines: 31 Xref: archiver1.google.com comp.std.c++:11422 James Kanze wrote: > I would argue that this is the correct interpretation. I'm not 100% > sure, however, since I don't think that there is any requirement > concerning the default constructor, and there is a guarantee that it > is NOT called in constructing the vector. (It may be called to > construct the argument to the constructor, of course.) I once reported that as a bug in some STL implementation. New objects were created by invoking the default constructor, then assigning, rather than by invoking the copy constructor. It was a bug; only by accident did it work that way. This typically comes up when an class contains a data member which is a reference. That reference has to be initialized during construction, and so the default constructor is usually not meaningful. Thus, there's a reason to get this right. John Nagle Animats --- [ 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 ]