This is what I have been getting while using the "new style "

/media/f/QT/Qt/QT/qtconnectivity/examples/bluetooth/CAT_BT_18112020/device.cpp:140: error: no matching function for call to 'DeviceDiscoveryDialog::connect(QListWidget*&, void (QListWidget::*)(QListWidgetItem*), QListWidget*&, <unresolved overloaded function type>)'
&QListWidget::addItem ); //slot
^