From -7870931501082549261 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,f5d433881cc29cff X-Google-Attributes: gidf78e5,public From: bparker@gil.com.au (Brian Parker) Subject: Re: Named return value optimisation- reprise. Date: 1997/06/20 Message-ID: <33a9d7e0.2094012@news.ipswich.gil.com.au>#1/1 X-Deja-AN: 251293636 References: <33a345bf.7425526@news.ipswich.gil.com.au> <33A478C1.329@acm.org> <33a4e2d5.24720499@news.ipswich.gil.com.au> <33A54D26.F46@acm.org> <5o3v6c$cv3@mulga.cs.mu.OZ.AU> <33A5A723.E9F@acm.org> <5o5mgd$mkv@mulga.cs.mu.OZ.AU> <33A6A1F9.D0E@acm.org> <5o7nd2$4ms@mulga.cs.mu.OZ.AU> X-Original-Date: Fri, 20 Jun 1997 02:04:33 GMT Organization: Global Info-Links News Server X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBFAgUBM6pCAOEDnX0m9pzZAQFV9AF+J3kobyU71GFUggiu3NkZM1KxJ+qCLO2Q UGOIVLgqimVPrtOEuns1pP9TjD2EeSGM =w6Pe Newsgroups: comp.std.c++ Originator: fjh@mundook.cs.mu.OZ.AU On 18 Jun 97 06:15:53 GMT, fjh@mundook.cs.mu.OZ.AU (Fergus Henderson) wrote: >Nope, your two example classes _are_ different from the outside: > > const C2 c2; > const_cast(c2).set_data(42); // fine > > const C1 c1; > const_cast(c1).set_data(42); // undefined behaviour That's a good point. The fact that a compiler cannot make constness "deep" (although logically it should) is exactly analogous to the problem of determining what memory an object consists of. ,Brian Parker (bparker@gil.com.au) --- [ 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 ] [ FAQ: http://reality.sgi.com/employees/austern_mti/std-c++/faq.html ] [ Policy: http://reality.sgi.com/employees/austern_mti/std-c++/policy.html ] [ Comments? mailto:std-c++-request@ncar.ucar.edu ]