From -6345244225437437969 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fc772,f84c8cecfc4d5b7f X-Google-Attributes: gidfc772,public X-Google-Thread: f78e5,a4f3c15d97de4122 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 2002-07-13 19:02:07 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!paloalto-snf1.gtei.net!denver-snf1.gtei.net!news.gtei.net!namche.sun.com!sunnews1.Eng.Sun.COM!engnews1.eng.sun.com!taumet!clamage From: Allan_W@my-dejanews.com (Allan W) Newsgroups: comp.std.c++,comp.lang.c++.moderated Subject: Re: Why don't constructors and destructors have return types? Date: 14 Jul 2002 01:51:10 GMT Organization: http://groups.google.com/ Lines: 41 Approved: stephen.clamage@sun.com (comp.std.c++) Message-ID: <23b84d65.0207121402.452015f@posting.google.com> References: <3D1FB54B.FFDC9969@bawi.org> <3d209e70.1346875@news.earthlink.net> <3d21c520.27573671@news.earthlink.net> <3d24ccd3.20691953@news.earthlink.net> <7uvaiug6ionjvtmhp8lks5k8s9qvdo12i5@4ax.com> <3d25e7c0.34024125@news.earthlink.net> <3d2c4170.15685078@207.217.77.25> NNTP-Posting-Host: taumet.eng.sun.com X-NNTP-Posting-Host: netlab.cs.rpi.edu X-Original-Date: 12 Jul 2002 15:02:26 -0700 X-Submission-Address: c++-submit@netlab.cs.rpi.edu X-Auth: PGPMoose V1.1 PGP comp.lang.c++.moderated iQBVAwUAPTAbOEHMCo9UcraBAQEjAgH+LIhJSEY4BXfr4wjeO5+0NL0Lz/VGoSXQ wm9wGRBQilLZrWqjGKXa/spDnFCZ7oYwnAXU73PysI/aWyro++stKA== =rubA X-Approved-For-Group: francis.moderator@robinton.demon.co.uk comp.lang.c++.moderated X-Scanned-By: MIMEDefang 2.3 (www dot roaringpenguin dot com slash mimedefang) X-MailScanner: Passed Content-Length: 1485 Originator: clamage@taumet Xref: archiver1.google.com comp.std.c++:12689 comp.lang.c++.moderated:46516 Gennaro Prota wrote > b) Changing 5.3.3p1 to explicitly state that sizeof considers > exclusively "complete objects" > > "The sizeof operator yields the number of bytes in the object > representation of [its operand -> *a complete object* whose type is > determined by its operand]." This might be feasible for objects that already have type_info. But it's a fundamental change, and shouldn't be taken lightly. class base { char x[4]; }; void foo(base *b) { std::cout << sizeof(base) << "-" << sizeof(*b); } class der : public base { char y[2]; }; int main() { Base b; foo(&b); std::cout << ", "; Der d; foo(&d); std::cout << std::endl; } What does this print? Under current rules, it prints "4-4, 4-4" unless alignment concerns make base bigger than 4 bytes. Under new rules it could be "4-4, 4-6" or "4-4, 4-8". Furthermore, sizeof() can no longer be performed at runtime except in constrained situation, such as sizeof(base) in the code above. [ Send an empty e-mail to c++-help@netlab.cs.rpi.edu for info ] [ about comp.lang.c++.moderated. First time posters: do this! ] [ 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 ]