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From: thomasw@hpcupt1.HP.COM (Thomas Wang)
Newsgroups: comp.lang.c++
Subject: Re: testing this==0
Message-ID: <7050021@hpcupt1.HP.COM>
Date: 27 Jun 90 01:13:15 GMT
References: <1990Jun26.175953.16763@uncecs.edu>
Organization: Hewlett Packard, Cupertino
Lines: 30

/ hpcupt1:comp.lang.c++ / harris@uncecs.edu (Mark Harris) / 10:59 am  Jun 26, 1990 /

>#include <stdio.h>
>struct test{
>  int a;
>  test(){
>    if(this==0)puts("zero");
>    else puts("nonzero");
>  }
>};

Testing or setting 'this' to 0 should not be done any more.  This is what I
use for testing heap versus stack objects:

// explain function
// Is this object allocated from the stack?
// This code is machine dependent.  It assumes stack have a higher address
// than heap space.
char base_ref_t::is_stack_object()
{
  char x;
  return ((unsigned int) this) > ((unsigned int) &x);
}

>    Mark Harris                            mail:harris@ecsvax(UUCP/BITNET)

 -Thomas Wang
              (Everything is an object.)
                                                     wang@hpdmsjlm.cup.hp.com
                                                     thomasw@hpcupt1.cup.hp.com