comp.lang.idl-pvwave archive: archive » Re: Attempt to store into an expression: Structure reference

Home » Public Forums » archive » Re: Attempt to store into an expression: Structure reference

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

Re: Attempt to store into an expression: Structure reference [message #63283 is a reply to message #63282]

Tue, 04 November 2008 08:39

Vince Hradil
Messages: 574
Registered: December 1999

Senior Member

On Nov 4, 10:21 am, greg.a...@googlemail.com wrote:
> I'm doing something wrong here, but what - I'm not sure...
>
> IDL> help,s.tab
> <Expression> POINTER = <PtrHeapVar26>
>
> IDL> help,*(s.tab)
> <PtrHeapVar26> STRUCT = -> TAB Array[2]
>
> IDL> help,(*(s.tab))[0]
> <Expression> STRUCT = -> TAB Array[1]
>
> IDL> help,((*(s.tab))[0]).img
> <Expression> POINTER = <NullPointer>
>
> IDL> ((*(s.tab))[0]).img=ptr_new(image)
> % Attempt to store into an expression: Structure reference.
>
> Any ideas why I can't assign something to this pointer?
>
> Greg

Because it's a null pointer. How was it created? When a pointer is
created without know what it's going to contain, you need to us /
ALLOCATE_HEAP.

Report message to a moderator

[Message index]

		Re: Attempt to store into an expression: Structure reference By: David Fanning on Tue, 04 November 2008 10:54
		Re: Attempt to store into an expression: Structure reference By: R.Bauer on Tue, 04 November 2008 09:40
		Re: Attempt to store into an expression: Structure reference By: David Fanning on Tue, 04 November 2008 09:12
		Re: Attempt to store into an expression: Structure reference By: greg.addr on Tue, 04 November 2008 08:58
		Re: Attempt to store into an expression: Structure reference By: Foldy Lajos on Tue, 04 November 2008 08:57
		Re: Attempt to store into an expression: Structure reference By: David Fanning on Tue, 04 November 2008 08:44
		Re: Attempt to store into an expression: Structure reference By: David Fanning on Tue, 04 November 2008 08:44
		Re: Attempt to store into an expression: Structure reference By: Vince Hradil on Tue, 04 November 2008 08:39
		Re: Attempt to store into an expression: Structure reference By: greg.addr on Wed, 05 November 2008 00:31

Previous Topic:	Read_grib under IDL 7.0
Next Topic:	array subtraction

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Thu Oct 09 20:45:50 PDT 2025

Total time taken to generate the page: 0.06105 seconds