  Item *get_equal_const_item(THD *thd, const Context &ctx, Item *const_item)
  {
    return (flags & ZEROFILL_FLAG) ?
           get_equal_zerofill_const_item(thd, ctx, const_item) :
           const_item;
  }
  Item *get_equal_const_item(THD *thd, const Context &ctx, Item *const_item)
  {
    return (flags & ZEROFILL_FLAG) ?
           get_equal_zerofill_const_item(thd, ctx, const_item) :
           const_item;
  }