string_view.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_STRING_VIEW_H
#define KNOWROB_PY_CONVERTER_STRING_VIEW_H
 
namespace knowrob::py {
    // This is needed for python to work with std::string_view.
    struct string_view_to_python_str {
        static PyObject *convert(std::string_view s) {
            return PyUnicode_FromStringAndSize(s.data(), s.size());
        }
    };
 
    // This is needed to map Python strings into std::string_view.
    struct python_str_to_string_view {
        static void *convertible(PyObject *obj_ptr) {
            if (!PyUnicode_Check(obj_ptr)) return 0;
            return obj_ptr;
        }
 
        static void construct(PyObject *obj_ptr, boost::python::converter::rvalue_from_python_stage1_data *data) {
            const char *value = PyUnicode_AsUTF8(obj_ptr);
            if (value == nullptr) boost::python::throw_error_already_set();
            void *storage = ((boost::python::converter::rvalue_from_python_storage<std::string_view> *) data)->storage.bytes;
            new(storage) std::string_view(value);
            data->convertible = storage;
        }
    };
 
    void register_string_view_converter() {
        boost::python::to_python_converter<std::string_view, string_view_to_python_str>();
        boost::python::converter::registry::push_back(
                &python_str_to_string_view::convertible,
                &python_str_to_string_view::construct,
                boost::python::type_id<std::string_view>()
        );
    }
}
 
#endif //KNOWROB_PY_CONVERTER_STRING_VIEW_H