UPDATE table SET ROW = function don't work

 I tried to update a table with SET ROW clause equal to a function (that return the same record type).

It's not gonna work.

PL/SQL: ORA-00904: : invalid identifier

It's look like that is not possible to update with a function an entire row.

I prepared i test case. if someone are interested.

CREATE TABLE UPDATE_CHAIN

(

   U_BASE        NUMBER (4),

   U_HIGH        NUMBER (4),

   U_AREA        NUMBER (8),

   U_PAIR        VARCHAR2 (1),

   U_PAIR_TEXT   VARCHAR2 (10)

);

INSERT INTO UPDATE_CHAIN (U_BASE, U_HIGH)

     VALUES (3, 5);

INSERT INTO UPDATE_CHAIN (U_BASE, U_HIGH)

     VALUES (4, 5);

CREATE OR REPLACE FUNCTION F_SET_NEW_ROW (I_ROW IN UPDATE_CHAIN%ROWTYPE)