c++ - 如果作业在附加之前完成，QFutureWatcher 的 finished() 信号会被触发吗？

Question

的finished()信号是否QFutureWatcher总是会被触发，即使 代表的并发作业在附加到QFuture之前已经完成？QFutureWatcherQFuture

考虑以下示例：

// Start some computation.
QFuture<int> future = QtConcurrent::run(...);

// [A] At this point some time may pass where the computation might finish concurrently

// Instaciate watcher
QFutureWatcher<int> watcher;

// Instantiate an object to receive singal
MyClass myObject;

// Connect slot to watcher's finished() signal
connect(&watcher, SIGNAL(finished()), &myObject, SLOT(handleFinished()));

// Attach watcher to the future
watcher.setFuture(future);

// [B] Will the handleFinished() slot be called at this point even if the concurrent job already completed in point [A] above?

而且，最重要的是，如果没有发生这种情况，handleFinished()在这种情况下如何让插槽始终被调用？