Method replace_callback

src/runtime/task/task.h:505–512

    //
    void fetch_current_handler(rpc_response_handler &cb) { cb = std::move(_cb); }
    void replace_callback(rpc_response_handler &&cb)
    {
        task_state cur_state = state();
        CHECK(cur_state == TASK_STATE_READY || cur_state == TASK_STATE_RUNNING,
              "invalid task_state: {}",
              enum_to_string(cur_state));
        _cb = std::move(cb);
    }
    void replace_callback(const rpc_response_handler &cb)
    {
        replace_callback(rpc_response_handler(cb));