Peter Petrov wrote:
Suppose that we have nested states, and we use state-local storage in the outer state. Now, for as long as we don't leave the outer state, (only making transitions between its inner states), it is natural to keep its storage. I.e. the lifetime of the storage should be the same as the logical lifetime of the state.
Judging from your brief description of your approach, I presume that leaving an inner-state will also destroy the outer-state, since they are the same object (you said: "inheritance is used to model states hierarchy").
You're right. It has a different model. There is no outer state. Inheritance is used only to reduce number of transitions from a group of states to one transition from their common base. Of course, you can store outer state data in base class as shared_ptr and pass this pointer to all derived states. -- Alexander Nasonov