template<typename T>
class lock_free_queue
{
private:
    static void increase_external_count(
        std::atomic<counted_node_ptr>& counter,
        counted_node_ptr& old_counter)
    {
        counted_node_ptr new_counter;
        do
        {
            new_counter=old_counter;
            ++new_counter.external_count;
        }
        while(!counter.compare_exchange_strong(
                  old_counter,new_counter,
                  std::memory_order_acquire,std::memory_order_relaxed));
        old_counter.external_count=new_counter.external_count;
    }
};