#include <cstdlib>
#include <iostream>
#include <memory>

using namespace std;

int main(int argc, char **argv) {
  // x contains a pointer to an int and has reference count 1.
  shared_ptr<int> x(new int(10));

  {
    // x and y now share the same pointer to an int, and they
    // share the reference count; the count is 2.
    shared_ptr<int> y = x;
    cout << "y = " << y << "  *y = " << *y << endl;
  }
  // y fell out of scope and was destroyed.  Therefore, the
  // reference count, which was previously seen by both x and y,
  // but now is seen only by x, is decremented to 1.
  cout << "x = " << x << "  *x = " << *x << endl;

  // A preferred way to create a shared pointer (because it never
  // exposes a standard pointer):
  shared_ptr<int> z = make_shared<int>(100);
  cout << "z = " << z << "  *z = " << *z << endl;

 return EXIT_SUCCESS;
}