From:	e9462 AT tc DOT hsa DOT nl (H.N. Oudejans)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Pointer Problem
Date:	8 Jan 1999 09:17:13 +0100
Organization:	Hogeschool Alkmaar, The Netherlands.
Lines:	31
Distribution:	all
Message-ID:	<774eu9$d6o$1@mimas.tc.hsa.nl>
NNTP-Posting-Host:	mimas.tc.hsa.nl
X-Trace:	metis.hsa.nl 915783433 16905 194.171.19.170 (8 Jan 1999 08:17:13 GMT)
X-Complaints-To:	usenet AT hsa DOT nl
NNTP-Posting-Date:	8 Jan 1999 08:17:13 GMT
Summary:	Pointer doesn't stay at the right value
Keywords:	Polymorph,Pointers
X-Newsreader:	NN version 6.5.1 (NOV)
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
Reply-To:	djgpp AT delorie DOT com

My name is Herman Oudejans and I got a big problem with pointers.

When I init a variable Ptr_Button,and then call a function, then the pointer is changed as (a result of polymorphy) ?!?
Here's some code to explain it a bit further:

Ptr_Button=new Button (.....)
AddGadget (InfoButton)


void AddGetget (Object * object)    //   Object is a parent of Button

In a debugger (rhide) ,the result is as follows

Ptr_Button (Button *) 0xa17055   // or some other address
object (Object *) 0xa17078 

The pointer points to the same object, so I can't delete Ptr_Button without destroying object as well. (Maybe because object is just a local).
The meaning of this all is to keep the pointer in a pointer-linked-list so I can safely delete it, but since the pointer is different delele won't work.

Can anybody help me to 

1) solve this problem
2) maybe help me to some code for some sort of collection object (a pointer-linked-list with polymorph items)

                                              Thanks in advance

 


  

- Raw text -