Ciclic dependency problem

resulting.cpp

//Resulting file after pre-processing ----
int get_total(std::vector<int> &v);

struct int_vector {
  //implementation details ...
  int size() { return _size; }
  int operator[](int pos) { 
    return _data[pos];
  }
  int *_data;
};

int get_total(std::vector<int> &v) {
  return std::accumulate(begin(v), end(v));
}