uninitialized_copy_n
using __STD::uninitialized_copy_n;
uninitialized_copy_n(__r->_M_data, __old_len, __new_data);
uninitialized_copy_n(__iter, __len, __new_data + __old_len);
uninitialized_copy_n(__iter, __len, __r->_M_data + __old_len);
uninitialized_copy_n(__leaf, __n, _M_buf_ptr);
uninitialized_copy_n(__s, __size, __buf);
uninitialized_copy_n(__s + __start_pos + _M_start, __req_len,