iterator for empty list

If I have a linked list which is empty can I do something like this?

Code:

---

std::list<int> l;
iter = l.end();

---

so I can test iter for l.end() later on?
it seems to work but it feels like its not good

Yes, you can, but following the principle of declaring variables near first use, I would try and only declare later on when I actually want to test for the end.

If the list is modified, is it guaranteed that end() won't change? I thought it's defined to point to one past the end of the container.

Doesn't work for vectors -

Code:

---

#include <iostream>
#include <vector>

int main() {
        std::vector<int> a;
        std::vector<int>::iterator end_it = a.end();
        a.push_back(5);
        std::cout << (a.end() == end_it) << std::endl;
}

---

For OP: why not just compare what you need to compare against l.end()?

Quote:

---

Originally Posted by cyberfish

If the list is modified, is it guaranteed that end() won't change?

---

Insertion to a std::list does not invalidate iterators to elements of the list, and deletion from a std::list only invalidates iterators to the deleted elements.

Quote:

---

Originally Posted by laserlight

Yes, you can, but following the principle of declaring variables near first use, I would try and only declare later on when I actually want to test for the end.

---

thanks :)

Ah I see. Thanks.