- Iterator& operator++();
- auto operator->() { return frontier.begin().operator->(); }
- auto operator*() const { return *frontier.begin(); }
-
- // If what the iterator sees next is the same, we consider them
- // to be the same iterator. This way, once the iterator has completed
- // its search, it will be "equal" to an iterator searching nothing
- bool operator==(const Iterator& other) { return this->frontier == other.frontier; }
- bool operator!=(const Iterator& other) { return not(this->operator==(other)); }
-
- using iterator_category = std::forward_iterator_tag;
- using difference_type = int; // # of steps between
- using value_type = UnfoldingEvent*;
- using pointer = value_type*;
- using reference = value_type&;