Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!ncar!husc6!ngo
From: ngo@tammy.harvard.edu (Tom Ngo)
Newsgroups: comp.lang.c++
Subject: Help--I want destructor whose action depends on link count
Message-ID: <NGO.90Nov7141525@tammy.harvard.edu>
Date: 7 Nov 90 19:15:25 GMT
Sender: news@husc6.harvard.edu
Distribution: comp
Organization: Harvard Chemistry Department
Lines: 25


  [ Please do not reply after November 14, 1990-- I will summarize ]

I have a class, A, of which multiple identical objects are typically
created.  I would like to save memory and time by eliminating the need
for duplicate objects.  An object would keep count of the number of
active pointers referencing it.  Calls to the destructor would
decrement this count, and memory would be freed only on reaching a
zero count.

Unix aside:  This is analogous to how the link count works in ln, rm.

I am having difficulty implementing this because in C++, memory
allocation and object initialization are distinct activities.  Thus,
new() is invoked before construction, and delete(), after destruction.

This seems like it ought to be a common problem, and I would
appreciate any pointers.  I will keep a count of the pointers and
self-destruct when the last one is gone.  (Ugh.)

Please e-mail to ngo@tammy.harvard.edu...
--
  Tom Ngo
  ngo@harvard.harvard.edu
  617/495-1768 lab number, leave message