1  template<bool _Const>
       2  struct _Iterator
       3  {
       4  private:
       5    static void mover (const _Iterator &arg = {}) noexcept (noexcept (arg));
       6      
       7  public:
       8    _Iterator() = default;
       9  
      10    friend void move (const _Iterator &arg2) noexcept (noexcept (mover (arg2)))
      11    {}
      12  };