Scott McKay <skottmckay@gmail.com> writes:

Is the following possible or am I doing something wrongly?

I have a custom smart pointer, and an abstract base class that is wrapped specifying smart_ptr<X> as the HeldType, as I want to treat the object as if it's automatically wrapped with a smart_ptr.

I then have a std::vector<smart_ptr<X>> exposed using the vector_indexing_suite with proxying turned off.

Basically something along these lines...

struct X_Wrapper: X { X_Wrapper(PyObject* py_self_): X(), py_self(py_self_) {}

X& run() { return call_method< X& >(py_self, "run"); } }

You should use the new-style polymorphism support (http://www.boost.org/libs/python/doc/v2/wrapper.html) although this probably has nothing to do with your problem.

class_< X, X_Wrapper, boost::noncopyable, smart_ptr< X > >("X", init<>()) .def("run", pure_virtual(&X::run), return_self<>()) ;

class_< std::vector< smart_ptr<X> > > ( "vector_X" ) .def( vector_indexing_suite< std::vector< smart_ptr<X> >, true >() ) ;

Then in the python code I want to implement the X interface and add the python object that does so to the vector.

class testX( X ):

def run( self ):

print "run" return self

tester = testX() vector = vector_X() vector.append( tester )

Doing so leads to a type error in the append (from the base_append of the vector_indexing_suite). The object type is a 'testX', which I thought would be held as a smart_ptr<X> under the covers and hence would be convertible, but I guess that isn't the case.

The problem is that you're missing an __init__ function in testX. Calling the __init__ function of the base class inside it (i.e. X.__init__(self)) is what causes the held smart_ptr<X> to be created.

As the vector takes a non-const I thought it was necessary to use the HeldType rather than register_ptr_to_python.

I'm not sure they're related.

Is there a way to make this work? I'm not sure I have everything setup correctly though, so perhaps I'm missing a piece.

I think the __init__ function will do it for you. -- Dave Abrahams Boost Consulting www.boost-consulting.com