Will the inefficiency of the postfix ++/-- operators be optimised away for STL iterators?

I know that the postfix versions of the increment/decrement operators will generally be optimised by the compiler for built-in types (i.e. no copy will be made), but is this the case for iterators?

They are essentially just overloaded operators, and could be implemented in any number of ways, but since their behaviour is strictly defined, can they be optimised, and if so, are they by any/many compilers?

#include <vector> 

void foo(std::vector<int>& v){
  for (std::vector<int>::iterator i = v.begin();
       i!=v.end();
       i++){  //will this get optimised by the compiler?
    *i += 20;
  }
}