setCentralWidget() without deleting prev widget

[Usernаme]

Hello. Sorry for my bad english..

How can I call setCetralWidget() that previous widget wasn't deleted?

it is the realization of setCentralWidget():
void QMainWindow::setCentralWidget(QWidget *widget)

1. {
2. Q_D(QMainWindow);
3. if (d->layout->centralWidget() && d->layout->centralWidget() != widget) {
4. d->layout->centralWidget()->hide();
5. d->layout->centralWidget()->deleteLater();
6. }
7. d->layout->setCentralWidget(widget);
8. }

so, setCentralWidget always call method deleteLater().

There is some ways to do it, for example:
centralWidget()->setParent(NULL);
//then we can use setCentralWidget()

1) Is there some other ways to do it?
2) Hmm.. can I redefenition deleteLater() in centralWidget()?