State machines don't have a native syntax in C++ at all, so you can structure them however you want. It's easy to structure a state machine, if needed, so that all (or some) states can handle the same event in the same way.
Downside of course is now you have a dependency on qt.
If you can afford to do things like this you can most likely use something other than C++ and save yourself a lot of headaches.
Surely you can understand that, despite the recent c++ hate, my job doesn't give a fuck and we aren't migrating our massive codebase from c++ to... anything.