Class Future

include/PyEventLoop.hh:178–234

   * @see https://docs.python.org/3/library/asyncio-future.html#asyncio.Future
   */
  struct Future {
  public:
    explicit Future(PyObject *future) : _future(future) {};
    Future(const Future &old) = delete; // forbid copy-initialization
    Future(Future &&old) : _future(std::exchange(old._future, nullptr)) {}; // clear the moved-from object
    ~Future() {
      Py_XDECREF(_future);
    }

    /**
     * @brief Mark the Future as done and set its result
     * @see https://docs.python.org/3/library/asyncio-future.html#asyncio.Future.set_result
     */
    void setResult(PyObject *result);

    /**
     * @brief Mark the Future as done and set an exception
     * @see https://docs.python.org/3/library/asyncio-future.html#asyncio.Future.set_exception
     */
    void setException(PyObject *exception);

    /**
     * @brief Add a callback to be run when the Future is done
     * @see https://docs.python.org/3.9/library/asyncio-future.html#asyncio.Future.add_done_callback
     */
    void addDoneCallback(PyObject *cb);

    /**
     * @brief Return True if the Future is cancelled.
     * @see https://docs.python.org/3.9/library/asyncio-future.html#asyncio.Future.cancelled
     */
    bool isCancelled();

    /**
     * @brief Get the result of the Future.
     * Would raise exception if the Future is pending, cancelled, or having an exception set.
     * @see https://docs.python.org/3.9/library/asyncio-future.html#asyncio.Future.result
     */
    PyObject *getResult();

    /**
     * @brief Get the exception object that was set on this Future, or `Py_None` if no exception was set.
     * Would raise an exception if the Future is pending or cancelled.
     * @see https://docs.python.org/3.9/library/asyncio-future.html#asyncio.Future.exception
     */
    PyObject *getException();

    /**
     * @brief Get the underlying `asyncio.Future` Python object
     */
    inline PyObject *getFutureObject() const {
      Py_INCREF(_future); // otherwise the object would be GC-ed as this `PyEventLoop::Future` destructs
      return _future;
    }
  protected:
    PyObject *_future;
  };