template <typename T>
class lock_free_queue {
private:
  static void free_external_counter(counted_node_ptr& old_node_ptr)
  {
    node* const ptr          = old_node_ptr.ptr;
    int const count_increase = old_node_ptr.external_count - 2;
    node_counter old_counter = ptr->count.load(std::memory_order_relaxed);
    node_counter new_counter;
    do {
      new_counter = old_counter;
      --new_counter.external_counters;
      new_counter.internal_count += count_increase;
    } while (!ptr->count.compare_exchange_strong(old_counter,
                                                 new_counter,
                                                 std::memory_order_acquire,
                                                 std::memory_order_relaxed));
    if (!new_counter.internal_count && !new_counter.external_counters) {
      delete ptr;
    }
  }
};