vector.h

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/*
 * This file is part of KnowRob, please consult
 * https://github.com/knowrob/knowrob for license details.
 */
 
#ifndef KNOWROB_PY_CONVERTER_VECTOR_H
#define KNOWROB_PY_CONVERTER_VECTOR_H
 
namespace knowrob::py {
    /*** python-list to c++-list */
    template<typename containedType>
    struct custom_vector_from_seq {
        custom_vector_from_seq() {
            boost::python::converter::registry::push_back(&convertible,
                                                          &construct,
                                                          boost::python::type_id<std::vector<containedType> >());
        }
 
        static void *convertible(PyObject *obj_ptr) {
            // the second condition is important, for some reason otherwise there were attempted conversions
            // of Body to list which failed afterwards.
            if (!PySequence_Check(obj_ptr) || !PyObject_HasAttrString(obj_ptr, "__len__")) return nullptr;
            return obj_ptr;
        }
 
        static void construct(PyObject *obj_ptr, boost::python::converter::rvalue_from_python_stage1_data *data) {
            void *storage = ((boost::python::converter::rvalue_from_python_storage<std::vector<containedType> > *) (data))->storage.bytes;
            new(storage) std::vector<containedType>();
            auto v = (std::vector<containedType> *) (storage);
            auto l = PySequence_Size(obj_ptr);
            if (l < 0) abort();
            v->reserve(l);
            for (int i = 0; i < l; i++) {
                v->push_back(boost::python::extract<containedType>(PySequence_GetItem(obj_ptr, i)));
            }
            data->convertible = storage;
        }
    };
}
 
#endif //KNOWROB_PY_CONVERTER_VECTOR_H