[C++-sig] Boost-python/pybindgen and wrapping member variables

[Gustavo Carneiro]

On Wed, Jan 20, 2010 at 5:43 PM, Ben Fitzpatrick <
bfitzpatrick at vtiinstruments.com> wrote:

>  Hi everyone,
>
>
>
> I think I’m finally getting the hang of this, I seem to have gotten almost
> everything in my project working thanks to Gustavo’s latest pybindgen patch.
> One of the remaining things I am having difficulty with is putting
> annotations on member variables of a class. I have something of the form:
>
>
>
> class foo{
>
>  <stuff>
>
> };
>
>
>
> class baz {
>
>   public:
>
>   foo* var;
>
> }
>
>
>
> The error I am getting from pybindgen is “WrapperWarning: Return value
> ‘::foo *’ error (used in baz::var [variable]):
> TypeConfigurationError(‘Either caller_owns_return or
> self.reference_existing_object must be given’)
>
>
>
>  I know that the issue is that I need to stick an annotation on there.
> Since the pointer is allocated and tracked by the underlying C++ code, I’m
> pretty sure that I need to put reference_existing_object on it. I’ve tried
> inserting “{‘reference_existing_object’ : ‘true’}” into the
> global_annotations table, and also inserting it into the
> parameter_annotations[“return”] dictionary. For kicks, I even tried both at
> once. No matter what I do I can’t get rid of the error, or see it show up in
> my final build, which leads me to believe there’s something I’m missing. I
> went and looked up the documentation for reference_existing_object, but of
> course none of their examples show how you could use it on a member
> variable. What am I missing?
>
You are not missing anything.  Annotations for member variables (pybindgen
calls them "instance attributes") were not implemented.

An oversight easily fixed:

http://bazaar.launchpad.net/~gjc/pybindgen/trunk/revision/742


>
>
> Thanks,
>
> Ben Fitzpatrick
>
> _______________________________________________
> Cplusplus-sig mailing list
> Cplusplus-sig at python.org
> http://mail.python.org/mailman/listinfo/cplusplus-sig
>



-- 
Gustavo J. A. M. Carneiro
INESC Porto, Telecommunications and Multimedia Unit
"The universe is always one step beyond logic." -- Frank Herbert
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/cplusplus-sig/attachments/20100120/546d1553/attachment.htm>