"reference to function" as result of a function - delphi

Question

i have a function that returns a function TFunc<Integer> which is reference to function:Integer.
and i have a procedure which takes a function TFunc<Integer> as argument, calls it and prints its result.
program Project1;
{$APPTYPE CONSOLE}
{$R *.res}
uses
System.SysUtils;
function GetFunction:TFunc<Integer>;
begin
result := function:Integer begin result := 42 end;
end;
procedure FunctionCall(AFunc:TFunc<Integer>);
var i:Integer;
begin
i := AFunc;
WriteLn(Format('Function Result = %d',[i]));
end;
begin
// FunctionCall(GetFunction); // error
FunctionCall(GetFunction()); // works as excpected
end.
this call (FunctionCall(GetFunction);) results in an error. and the call with () works as excpected.
my question is:
when in delphi do i need brakets to call a function and when not (i thought that i never need them)
or
shouldn't i need them and is it a bug?
i work with delphi xe5 on windows 7 dcc32.

Answer 1

If what you report is correct (and see below for more on that), then you would have found a bug, I believe.
This code:
FunctionCall(GetFunction);
should not compile. Indeed it does not compile when I try to compile it in XE3, XE4, XE5, XE6 and XE7. It does not compile because, in this particular context, the compiler interprets GetFunction as being of type
function: TFunc<Integer>
All above mentioned compilers object with this error message:
[dcc32 Error] E2010 Incompatible types: 'System.SysUtils.TFunc' and 'Procedure'
So, if you have somehow (perhaps with some compiler options), managed to make that code compile then I can only believe that is due to a bug.
You should deal with this by applying the parentheses so that the compiler can understand that you wish to call GetFunction, not refer to it.
FunctionCall(GetFunction());