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

That depends on what you need:

If you need genericity, use std::advance(it,2). If someone comes along and changes your std::vector into a std::list, the code will still compile, even though advancing now takes linear time instead of constant time.

If you need performance, use it+=2. If someone comes along and changes your std::vector into a std::list, the code will fail to compile, pointing (maybe with a helpful comment) at a serious performance issue.