How to increment an iterator by 2?

Question

Can anybody tell me how to increment the iterator by 2?

iter++ is available - do I have to do iter+2? How can I achieve this?

Answer 1

http://www.cplusplus.com/reference/std/iterator/advance/

std::advance(it,n);

where n is 2 in your case.

The beauty of this function is, that If "it" is an random access iterator, the fast

it += n

operation is used (i.e. vector<,,>::iterator). Otherwise its rendered to

for(int i = 0; i < n; i++)
    ++it;

(i.e. list<..>::iterator)