Predecrement |
--i |
i is dereferenceable or past-the-end. There exists a dereferenceable iterator j such that i == ++j. |
i is modified to point to the previous element. |
i is dereferenceable. &i = &--i . If i == j , then --i == --j . If j is dereferenceable and i == ++j , then --i == j. |