#include <vector>
std::vector<int> get_stuff( int how_many, std::vector<int> pre_buff = std::vector<int>() ) {
  pre_buff.clear();
  for (int i = 0; i < how_many; ++i)
    pre_buff.push_back(i);
  // blah blah
  return pre_buff;
}
#include <iostream>
int main() {
    auto v = get_stuff(7);
    for (auto x:v)
      std::cout << x << "\n";
}