#include <iostream>
#include <vector>
#include <functional>
using namespace std;

int main (int, char**) {
  int object = 21; // half of the answer
  vector<reference_wrapper<int>> v;
  v.push_back(object);
  v[0].get() = 42; // assignment needs explicit conversion of lhs to a real reference
  cout << "the answer is " << object << endl;
  return 0;
}