Does std::next check if we are already at the end of the container?

Question

Suppose I have an iterator std::list::iterator it = mylist.begin() of a container, and I call

iterator it2 = std::next(it,1);

Does std::next check if it == mylist.end()?

The behavior is undefined if the specified sequence of increments or decrements would require that a non-incrementable iterator (such as the past-the-end iterator) is incremented, or that a non-decrementable iterator (such as the front iterator or the singular iterator) is decremented. — Hariom Singh, Aug 17 '17 at 00:22

score 1 · Answer 1 · answered Aug 17 '17 at 00:13

1

No, the program was blocking in that situation. You should check yourself:

if (it != mylist.end())
    it2 = std::next(it,1);

answered Aug 17 '17 at 00:13

Andrea Araldo

1 Answers1