comp.lang.idl-pvwave archive: archive » Re: IDL Shapefile Object

Home » Public Forums » archive » Re: IDL Shapefile Object

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: IDL Shapefile Object [message #28360 is a reply to message #28295]

Mon, 03 December 2001 07:15

mvukovic
Messages: 63
Registered: July 1998

Member

David Fanning <david@dfanning.com> wrote in message news:<MPG.1670836a9029670e9897a1@news.frii.com>...
> Mark Hadfield (m.hadfield@niwa.cri.nz) writes:
>
>> Hey, I didn't know you *could* supply arguments to OBJ_DESTROY (though I
>> should have known because it's right there in the OBJ_DESTROY
>> documentation). Has anyone actually written code that *uses* this feature.
>> And if so, why? It seems to me that when you tell an object to destroy
>> itself, then it's up to the object to know how to do it.
>
> I've never used it. (Guess I should make a habit
> of reading the documentation that *is* there!)
> But I can imagine a case for it.
>
> Suppose one of the fields for the object was a
> pointer to some image data. The same image pointer
> might be present in several objects (to save
> copying the huge image). Any decent object cleanup
> routine would certainly free the pointer, but maybe
> you don't want it destroyed because then the other
> objects that are using it wouldn't work properly.
>
> In this case a HANG_ON_DONT_DO_IT keyword on the cleanup
> method might be appropriate.
>
> Cheers,
>
> David

An object should know what heap variables it created, and thus, only
destroy those heap variables (that the object itself created). All
other heap variables that were passed to it from the outside should
not be within its responsabilities.

Mirko

Report message to a moderator

[Message index]

		Re: IDL Shapefile Object By: Kelly Dean on Fri, 30 November 2001 11:52
		Re: IDL Shapefile Object By: alt on Thu, 29 November 2001 19:29
		Re: IDL Shapefile Object By: Mark Hadfield on Thu, 29 November 2001 17:26
		Re: IDL Shapefile Object By: David Fanning on Thu, 29 November 2001 16:40
		Re: IDL Shapefile Object By: Mark Hadfield on Thu, 29 November 2001 15:47
		Re: IDL Shapefile Object By: David Fanning on Thu, 29 November 2001 14:31
		Re: IDL Shapefile Object By: David Fanning on Thu, 29 November 2001 13:26
		Re: IDL Shapefile Object By: mvukovic on Mon, 03 December 2001 07:15

Previous Topic:	Re: Sparse matrix algorithms
Next Topic:	Re: Setting history size in idlwave

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 16:52:06 PDT 2025

Total time taken to generate the page: 0.00378 seconds