How To Update Using A Function

Take a table, where not all the columns are populated:

CREATE TABLE #T (A int, B int, C int, D int)
INSERT #T (A,B) VALUES (1,2)
INSERT #T (A,B) VALUES (3,4)
INSERT #T (A,B) VALUES (5,6)
INSERT #T (A,B) VALUES (7,8)
INSERT #T (A,B) VALUES (9,10)

The values for C and D can be computed as functions of A and B. For this
example, let's say they are twice A and three times B, respectively:

CREATE FUNCTION dbo.F(@A int,@B int)
RETURNS @Tbl TABLE (X int, Y int)
AS BEGIN
INSERT @Tbl (X,Y) VALUES (@A*2, @B*3)
RETURN
END

Now we use the function to compute the other columns:

UPDATE #T SET C=X, D=Y
FROM dbo.F(A,B)

Right? Well, no. Instead, I get this message:

Server: Msg 155, Level 15, State 1, Line 2
'A' is not a recognized OPTIMIZER LOCK HINTS option.

Any suggestions? I would like to use this structure, if possible.

Jim Geissman
Countrywide Home Loans