  Tmp_field_param(bool group,
                  bool modify_item,
                  bool table_cant_handle_bit_fields,
                  bool make_copy_field)
   :m_group(group),
    m_modify_item(modify_item),
    m_table_cant_handle_bit_fields(table_cant_handle_bit_fields),
    m_make_copy_field(make_copy_field)
  { }