/*
 * Return the next Joystick::Event from a Joystick::Device object.
 *
 * Note: For performance reasons, only one joystick event is allocated
 * per device.  Calling this method will silently overwrite old events
 * for this device.
 *  
 * This method will block if no data is waiting to be read, so you
 * should probably test the Joystick::Device object with
 * Joystick::Device#pending? before calling this method.
 *
 *
 * Aliases:
 *   Joystick::Device::ev
 *   Joystick::Device::event
 *   Joystick::Device::next_ev
 *
 * Example:
 *   ev = joy.next_event
 *
 */
static VALUE j_dev_ev(VALUE self) {