How is end() implemented in STL containers?

Question

So when we need to traverse a container from start to end we write something like

for (i = v->begin(); i != v->end(); i++)

assuming i

Answer 1

The stl specification guarantees that end will be one past the end See here. That will always be the case. Exactly how it does this can depend on the implementation (sometimes the values is just set to null for example), but rest assured your loop will be OK as long as v is a valid pointer.