No W1035 for Result of type string

RadStudio XE2 (default Hints and warning settings).

Empty function with Result of type Integer (Boolean etc.) like this:

function W1035Test: Integer;
begin
end;

shows warning W1035. That's all right. But after changing return data type to string

function W1035Test: string;
begin
end;

no warning shown. Why? Is it possible to turn it on?