Article View: comp.std.c++
Article #2498Re: Virtual functions and destructors
From: Herb Sutter
Date: Fri, 10 Nov 1995 19:30
Date: Fri, 10 Nov 1995 19:30
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1862 bytes
In article <199511100139.UAA11974@starling.WPI.EDU>, Chris Parker <parker@owl.WPI.EDU> wrote: > The thing that doesn't work for me is that the pointer type is >different, but it still has the same pointer value. At the low-level, you >are freeing the same block of memory either way. In order to >call a destructor, the system needs to convert the pointer to a class type >instance anyway. I don't follow. To begin with, you certainly often do have different pointer values for the same object depending on which base pointer(s) you use to access it. Simple example: Base classes B1 and B2, derived class D from both bases, and any D object will have a different pointer value when viewed through a B1* and a B2*; a B1* points to the "B1 part" of the derived object and a B2* points to the "B2 part" of the derived object. If you fix that first sentence I think you'll see how to fix the rest too. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Herb Sutter 2228 Urwin, Ste 102 voice (416) 618-0184 Connected Object Solutions Oakville ON Canada L6L 2T2 fax (905) 847-6019 --- [ comp.std.c++ is moderated. Submission address: std-c++@ncar.ucar.edu. Contact address: std-c++-request@ncar.ucar.edu. The moderation policy is summarized in http://dogbert.lbl.gov/~matt/std-c++/policy.html. ]
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Path: arc1-ca.pugleaf.net!128.32.155.1!matt From: herbs@interlog.com (Herb Sutter) Newsgroups: comp.std.c++ Subject: Re: Virtual functions and destructors Date: 10 Nov 1995 19:30:44 GMT Organization: Connected Object Solutions (div of Daystar Software Systems Design Inc.) Approved: matt@physics2.Berkeley.EDU (Matt Austern) Message-ID: <199511101834.NAA20540@gold.interlog.com> References: <199511100139.UAA11974@starling.WPI.EDU> NNTP-Posting-Host: physics2.berkeley.edu