Basically it looks like multi helpers don’t actually work with overloaded methods and simply choses the last helper declared. Should I fix this? Seems unlikely we would not notice this before but maybe we did.

{$modeswitch typehelpers}
{$modeswitch multihelpers}
type
  TMyHelper1 = type helper for integer
    procedure DoThis(f: integer);
  end;
  TMyHelper2 = type helper for integer
    procedure DoThis(f: string);
  end;
procedure TMyHelper1.DoThis(f: integer);
begin
  writeln(self, ' => ', f);
end;
procedure TMyHelper2.DoThis(f: string);
begin
  writeln(self, ' => ', f);
end;
var
  i: integer = 0;
begin
  i.DoThis(0);  // Got "ShortInt", expected “ShortString"

Regards,
Ryan Joseph

If you fix this, then I think you should make sure it is only done when the overload; keyword is present. For regular classes, searching for an overload match stops also at the current class (? unit) if the overload keyword is not present.

Michael.