Advance iterator for the std::vector std::advance VS operator +?

Question

I found myself writing the following a lot:

int location =2;
vector vec;
vector::iterator it=vec.begin();

/..../
std::advance(it, location         


        

Answer 1

It depends on the iterator. it=it+5 is faster if it's supported (it's only supported on random access iterators). If you want to advance a less-capable iterator (e.g. a forward iterator, or a bidirectional iterator), then you can use std::advance, but it's slower because it actually walks across all of the intermediate elements.