Hex number literal in MySQL stored function - mysql

Question

I want to use hexadecimal literals in the code of a MySQL function that does operations with bit masks on BIGINTs.
According to the MySQL 5.6 manual, I can use hexadecimal literals for integer values.
This works from an SQL statement in MySQL 5.6:
mysql> SELECT CAST(0x0055aa55aa55aaff AS UNSIGNED);
+--------------------------------------+
| CAST(0x0055aa55aa55aaff AS UNSIGNED) |
+--------------------------------------+
| 24112657927088895 |
+--------------------------------------+
1 row in set (0.01 sec)
I'm now trying to use the same syntax from a stored function, on the same MySQL:
DROP FUNCTION IF EXISTS _test_hex_literal;
DELIMITER $$
CREATE FUNCTION _test_hex_literal()
RETURN BIGINT UNSIGNED
DETERMINISTIC
NO SQL
BEGIN
RETURN CAST(0x0055aa55aa55aaff AS UNSIGNED);
END;
$$
DELIMITER ;
SELECT _test_hex_literal();
DROP FUNCTION IF EXISTS _test_hex_literal;
But MySQL 5.6 is rejecting my code:
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'RETURN BIGINT UNSIGNED
DETERMINISTIC
NO SQL
BEGIN
RETURN CAST(0x0055' at line 2
Am I doing something wrong, or is it a bug in MySQL?
If this is a MySQL bug, is there a workaround to use hexadecimal constants in the source code of my function?

Answer 1

Simple typo: I wrote RETURN instead of RETURNS in the function signature.
Here is the fixed code:
DROP FUNCTION IF EXISTS _test_hex_literal;
DELIMITER $$
CREATE FUNCTION _test_hex_literal()
RETURNS BIGINT UNSIGNED
DETERMINISTIC
NO SQL
BEGIN
RETURN CAST(0x0055aa55aa55aaff AS UNSIGNED);
END;
$$
DELIMITER ;
SELECT _test_hex_literal();
DROP FUNCTION IF EXISTS _test_hex_literal;

Answer 2

The error complaints about RETURN, not hexadecimal literals:
You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near 'RETURN BIGINT UNSIGNED
DETERMINISTIC
NO SQL BEGIN
RETURN CAST(0x0055'
Here's the syntax:
CREATE
[DEFINER = { user | CURRENT_USER }]
FUNCTION sp_name ([func_parameter[,...]])
RETURNS type
^
[characteristic ...] routine_body