template<class T>
  class ThreadSafeObject
  {
  public:
    class WithLock
    {
    public:
      WithLock(ThreadSafeObject<T> *tsobj)
        : tsobj_(tsobj)
      {
        tsobj_->mx_.lock();
      }

      ~WithLock()
      {
        tsobj_->mx_.unlock();
      }

      T& operator*() { return tsobj_->obj_; }
      T* operator->() { return &tsobj_->obj_; }

    private:
      ThreadSafeObject<T> *tsobj_;
    }

    WithLock withLock()
    {
      return WithLock(this);
    }

    T& operator*() { return obj_; }
    T* operator->() { return &obj_; }

  private:
    T obj_;
    std::mutex mx_;
  };