#include <memory>
#include <string>

struct User {
  int id = 30;
  std::string name = "steph";
};

// libc++ stores unique_ptr data in a compressed pair, which has a specialized
// representation when the type of the second element is an empty class. So
// we need a deleter class with a dummy data member to trigger the other path.
struct NonEmptyIntDeleter {
  void operator()(int* ptr) { delete ptr; }

  int dummy_ = 9999;
};

int main() {
  std::unique_ptr<int> up_empty;
  std::unique_ptr<int> up_int = std::make_unique<int>(10);
  std::unique_ptr<std::string> up_str = std::make_unique<std::string>("hello");
  std::unique_ptr<int> &up_int_ref = up_int;
  std::unique_ptr<int> &&up_int_ref_ref = std::make_unique<int>(10);
  std::unique_ptr<User> up_user = std::make_unique<User>();
  auto up_non_empty_deleter =
      std::unique_ptr<int, NonEmptyIntDeleter>(new int(1234));

  return 0; // break here
}