QRandomGenerator was introduced in 5.10 and qrand has since been
deprecated. QRandomGenerator::global() returns a global instance that
has been securely seeded. QRandomGenerator provides methods that
generate values within ranges, so taking a modulus of the result isn't
necessary.
When a closure involves an ObjectHelper, a connection is made from the
receiver's destroyed signal and the helper object's deleteLater slot. Since
the signal between the sender and the helper object isn't disconnected until
either object is actually destroyed, this leaves a hole where the helper
holds a pointer to an invalid receiver object, but is still able to receive
the signal connected to its Invoke slot.
Instead of connecting the destroyed signal to deleteLater, connect it to a new
TearDown slot that immediately disconnects the signal then calls deleteLater.
Jim Broadus
John Maguire
David Sansome