The following tasks:

• MDEV-12307 ROW data type for built-in function return values
• MDEV-12252 ROW data type for stored function return values
  will implement returning ROW type values from stored and SP functions.

DROP FUNCTION IF EXISTS f1;

DELIMITER $$

CREATE FUNCTION f1(a INT, b VARCHAR(32)) RETURNS ROW(a INT, b VARCHAR(32))

BEGIN

  RETURN ROW(a,b);

END;

$$

DELIMITER ;

Under terms of this task will allow to use fields of the returned values directly:

SELECT f1(1,'b1').a;