[vtkusers] Breaking GC loops

[Kenneth Porter]

--On Friday, February 19, 2010 6:48 PM -0800 Kenneth Porter 
<shiva at sewingwitch.com> wrote:

>> Keep in mind that in order for this to work, you have to be sure that all
>> the references in the loop are reported.  If any are missing, the
>> references can never be collected.
>
> Very interesting. I'll have to try this out.

Unfortunately this doesn't seem to work with the window/interactor/style 
loop, because the window and interactor are not reporting their reference 
to the style (nor to each other).

The weak pointer does work, at the cost of needing to test for the pointer 
being non-null before use.