From 6416348557933613949 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,db4807a3f0a1e742 X-Google-Attributes: gidf78e5,public X-Google-ArrivalTime: 1994-08-01 12:10:44 PST Newsgroups: comp.std.c++ Path: bga.com!news.sprintlink.net!sundog.tiac.net!usenet.elf.com!news2.near.net!MathWorks.Com!yeshua.marcam.com!zip.eecs.umich.edu!newsxfer.itd.umich.edu!isclient.merit.edu!msuinfo!harbinger.cc.monash.edu.au!news.cs.su.oz.au!metro!news From: maxtal@physics.su.OZ.AU (John Max Skaller) Subject: Re: Multiple inheritance and delete Message-ID: Sender: news@ucc.su.OZ.AU Nntp-Posting-Host: physics.su.oz.au Organization: School of Physics, University of Sydney, Australia References: <1994Jul27.022108.252@corona.com> Date: Mon, 1 Aug 1994 18:16:39 GMT Lines: 34 In article <1994Jul27.022108.252@corona.com> pkron@corona.com writes: >From: maxtal@physics.su.OZ.AU (John Max Skaller) (change default of member functions to "virtual"). > >> It would also break REAMS of C++ code, for no good reason >> other than to change a default to your liking. Even if >> your liking is shared by many, that is not enough to zap >> almost all C++ code in existence. > >Would it? Yes. In C++ there are two distinct kinds of class: a) polymorphic b) non-polymorphic and a whole lot of the language like RTTI works differently for polymorphic classes. Changing the default makes simple C structs with a few member functions in them polymorphic when they used to be non-polymorphic. Indeed, ALL C structs would become polymorphic because their destructors would be implicitly virtual -- which would destroy the ability to do aliasing based on knowledge of layout. The default is "non-virtual" because it has to be for compatibility withe C. -- JOHN (MAX) SKALLER, INTERNET:maxtal@suphys.physics.su.oz.au Maxtal Pty Ltd, 81A Glebe Point Rd, GLEBE Mem: SA IT/9/22,SC22/WG21 NSW 2037, AUSTRALIA Phone: 61-2-566-2189