Regress this iterator to the previous valid data element, and return by value the value of this iterator before it was decremented. If there is no preceding data element, the value of reverse_iterator(*this) will be rend().
Regress this iterator to the previous valid data element, and return by value the value of this iterator before it was decremented. If there is no preceding data element, the value of reverse_iterator(*this) will be rend().