Marc Santhoff wrote:
Am Sonntag, den 18.05.2008, 23:41 +0200 schrieb Graeme Geldenhuys:
2008/5/18 Marc Santhoff <[EMAIL PROTECTED]>:
Since the compiler dod not warn about using the "as" operator I assume
it is safe? Like this:
procedure TObservable.DeRegister( obsv: IObserver );
var
i: integer;
begin
if (fObservers.count<=0) then exit;
for i:=0 to fObservers.count-1 do begin
if ((fObservers[i] as IObserver)=obsv) then begin
I'm not a big Interfaces expert, but as for as I know using 'as' like
that with Interfaces actually translates to a QueryInterface() call
internally, which is why it is allowed. I vaguely remember as issue
between CORBA and COM interfaces and the 'as' call, because CORBA
interfaces do not have a QueryInterface() implementation. Well,
something like that... :-)
Okay, so there are still some unknowns.
CORBA interfaces do not include the following methods. These are only
relevant to COM interfaces.
function QueryInterface(const iid: tguid; out obj): longint; stdcall;
function _AddRef: longint; stdcall;
function _Release: longint; stdcall;
Everybody I know uses COM interfaces, except for one developers - Martin
from MSEgui project. FPC defaults to COM style interfaces as well.
Regards,
- Graeme -
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