unique_ptr_example.cpp

struct Widget {
  Widget() { cout << "Widget created" << endl; }
  ~Widget() { cout << "Widget destroyed" << endl; }
};

unique_ptr<Widget> createWindow() {
  return make_unique<Widget>();
}

int main() {
  auto w = createWindow();
  ASSERT(w);
  // auto w2 = widget; // error: unique_ptr has no copy-constructor
  auto w3 = move(widget); // w3 owns now the widget, w is empty
  ASSERT(w3 && !w);
  // w3 calls destructor of widget; only one object at a time owns the Widget
  return 0;
}

There is no variable 'widget'. So line 14 should be 'auto w3 = move(w)', and line 13 should contain 'auto w2 = w ...'

- auto w3 = move(widget);
+ auto w3 = move(w);