In the {$T+} or {$TYPEDADDRESS ON} state, the @ operator, when applied to a variable, returns a result of type ^T, if the type of the variable is T. In the {$T-} state, the result is always an untyped pointer, which is assignment compatible with all other pointer types. This directive is equivalent to the -Sy command-line option.
For example, the following code will not compile:
{$T+}
Var
I : Integer;
P : PChar;
begin
P:=@I;
end.
The compiler will give a type mismatch error:
testt.pp(8,6) Error: Incompatible types: got "^SmallInt" expected "PChar"
By default however, the address operator returns an untyped pointer.