On Mon, 13 Aug 2012 23:07:07 +0200, mathias.b...@gmx.de wrote: > Hi, > > I have a C++ class "Project", which I expose to Python > via sip. > In Python, I sub-class: > > class Derived(Project): > ... > > In addition, there is a Python factory function which creates an > instance of "Derived" and returns it: > > def f(): > return Derived(...) > > I call this function from withing C++, and feed the return > value into "sipConvertToType", in order to create a wrapper > of type "Project", so I can call methods of the returned > "Derived" instance from within C++, using the wrapper. > > Since the "Derived" instance is created by Python, it is > owned by Python. > Is there a way to transfer ownership to C++ without using any > additional objects? I want the Python part to stick to the > C++ wrapper until the latter is destroyed, at which point > the Python part should also be automatically disposed, without > any need to micro-manage the Python part myself.
That will happen automatically anyway so long as Derived has a virtual dtor. The Python object will only ever be destroyed when its reference count reaches 0, irrespective of the state of the C++ instance. > In the sip sources, I can see a flag "SIP_CPP_HAS_REF" that > might just achieve that, but there appears to be no official > way to use it. To transfer ownership of a Python object to C++ (ie. to control whether the Python dealloc code calls the C++ dtor) use... http://www.riverbankcomputing.com/static/Docs/sip4/c_api.html#sipTransferTo Phil _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
