I am trying to expose a C++ function in Python. This function does not take any inputs, and it returns a structure which consists of a string array and a multidimentional integer array. When I try to compile it, it gives me following error: c:\boost\boost/python/detail/caller.hpp(199) : error C2027: use of undefined type 'boost::python::detail::specify_a_return_value_policy_to_wrap_functions_returning<T>' with [ T=result_t ] c:\boost\boost/python/detail/caller.hpp(176) : while compiling class template member function 'PyObject *boost::python::detail::caller_arity<1>::impl<F,Policies,Sig>::operator ()(PyObject *,PyObject *)' with [ F=DQEasy *(__thiscall DQEasy::* )(void), Policies=boost::python::default_call_policies, Sig=boost::mpl::vector2<DQEasy *,DQEasy &> ] ///////////// My function looks like this: DQEasy* DQEasy::RequestToResponse() { int size(0); std::string user = "O066144"; std::string url = "dataquery-dev.ny.jpmorgan.com:6555"; DQP* request = getBaseRequest(); addValidContext(request, user); std::string expressionList[] = {"DB(FHR,TB3,MIDYLD)","DB(FHR,TB6,MIDYLD)"}; size = sizeof(expressionList)/sizeof(std::string); DQEasy::addExressions(request, expressionList, size); std::string outputTypeArray[] = {"data","stats"}; size = sizeof(outputTypeArray)/sizeof(std::string); DQEasy::addOutputTypes(request, outputTypeArray, size); DQP *response = DQEasy::getResponse(request, url); DQEasy *output = DQEasy::parseDQP(response); return output; } #include <C:/boost/boost/python.hpp> #include <C:/boost/boost/python/module.hpp> #include <C:/boost/boost/python/def.hpp> using namespace boost::python; BOOST_PYTHON_MODULE(DQEasy) { //Export the class to Python class_<DQEasy>("DQEasy") .def("RequestToResponse", &DQEasy::RequestToResponse) ; } Any clue will be quite helpful. I apologize if the message is too long. Thank you