Hi there, I am creating binding for some C++ classes and I need to be able to subclass exposed C++ classes in Python (and pass subclassed instances back in to C++ code).
I was able to make this work by following this example: http://www.boost.org/doc/libs/1_57_0/libs/python/doc/tutorial/doc/html/python/exposing.html#python.class_virtual_functions and creating binding for both: original C++ classes and ‘wrapper’ structs. This however create inconvenience and path for errors because now users need to remember to use different base class when subclassing C++ classes. Is there is a way to achieve subclassing functionality by exposing one class instead of two? When I tries to use class exposed as ’wrapper’ as substitute for C++ original class i am getting a segfault error (see example below). Is there is something wrong with a way i create a wrapper-class or it is not intended to work as substitute for a base class? Thanks, Ernie. Python code: ———————— from subclass import * class B(A_Wrapper): def __init__(self): A_Wrapper.__init__(self) def info(self): print 'B info!' a = A(); a.info(); print '1' b = B(); b.info(); print '2' aw = A_Wrapper(); print '3'; aw.info(); print '4' # <-- segfault before '4' got printed C++ code: ———————— #include <iostream> #include <boost/python.hpp> class A { public: virtual ~A() { std::cout << "A destructor for object: " << this << std::endl; } virtual void info() { std::cout << "C++ A info for object" << this << std::endl; } }; struct A_Wrapper : A, boost::python::wrapper<A> { A_Wrapper() : A() {} void info() {this->get_override("info")(); } }; BOOST_PYTHON_MODULE(subclass) { boost::python::class_<A, boost::noncopyable>("A") .def("info", &A::info) ; boost::python::class_<A_Wrapper, boost::noncopyable>("A_Wrapper", boost::python::init <>() ) .def("info", &A_Wrapper::info) ; }
_______________________________________________ Cplusplus-sig mailing list Cplusplus-sig@python.org https://mail.python.org/mailman/listinfo/cplusplus-sig
