I have implemented a custom QAbstractItemModel subclass, and from my understanding, the QAbstractItemModel::sort() method can be overridden in a derived class to implement custom sorting logic, which I did.
However, I haven't included any code to emit a signal for view updates, because I'm not sure if it is necessary to do so within the sort() function.
Is the caller of the sort() function responsible for notifying the view, or should the sort() function handle this itself?