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Re: pointer question
Ted Graves wrote:
> Hi all,
> Another lurker question ... let's say you define a pointer using the PTR_NEW
> function and assign to a variable x. As long as you keep track of x and don't
> reassign x and lose the pointer to the heap variable, things are great. You
> can remove the heap variable from memory using the PTR_FREE procedure.
> But now let's say i have a function TEST that takes a pointer as an argument,
> and i want to create a pointer on the fly to use in TEST. So i do something
> result = TEST(PTR_NEW(value))
> where value is whatever i want the heap variable to be. What happens to the
> heap variable assigned in this statement after TEST returns? I'm assuming
> from that because of the way it was created, a heap variable now exists that i
> can't easily get rid of without using HEAP_GC.
> Me and my sloppy programming ...
On an only slightly related note, does everyone know that you can recover a
pointer to a "lost" heap variable using ptr_valid? Here's an example:
IDL> a='oh no, I overwrote my pointer variable'
# Pointer: 1
# Object : 0
<PtrHeapVar4> INT = 1
You can also get a vector of pointers to every heap variable using:
While this isn't exactly useful programatically, it may get you out of a pinch.