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From: mjv@objects.mv.com (Michael J. Vilot)
Newsgroups: comp.lang.c++
Subject: Re: Overloaded operator new VS. inheritance
Message-ID: <1149@zinn.MV.COM>
Date: 27 Jan 91 19:07:11 GMT
Sender: nuucp@zinn.MV.COM
Lines: 18

Tom Keffer commented on the subtleties induced by inheriting operators new and
delete, and proposed a language extension to deal with the problem.

First, let me point out that the problem he cited does not require a language
extension to solve it.  Tom's example failed to take advantage of an existing
feature of overloading operator delete:  specifically, the form taking a second
argument of type size_t (ARM, p. 283):
    void operator delete(void*, size_t);
If the classes involved in inheritance provide a virtual destructor, the right
size should get passed to delete.

Second, I applied exactly this technique to the Managed and Controlled forms of
the C++ Booch Components library.  It works just fine, at the cost of a slightly
more sophisticated free list manager (it keeps the free lists sorted by size).

--
Mike Vilot,  ObjectWare Inc, Nashua NH
mjv@objects.mv.com  (UUCP:  ...!decvax!zinn!objects!mjv)