Function gio_sys::g_socket_client_connect_to_service_async

pub unsafe extern fn g_socket_client_connect_to_service_async(client: *mut GSocketClient,
                                                              domain: *const c_char,
                                                              service: *const c_char,
                                                              cancellable: *mut GCancellable,
                                                              callback: GAsyncReadyCallback,
                                                              user_data: gpointer)