BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  "is" operator equivalent for interfaces?          BorlandTalk.com Forum Index -> Delphi (General) View previous topic :: View next topic   Author Message Guest Posted: Mon Jul 21, 2008 4:05 pm    Post subject: "is" operator equivalent for interfaces? I'm trying to make sure that any object passed to the write parameter of a property implements a certain interface. The obvious way for checking inheritance, the "is" operator, doesn't seem to work. Is there a different way to do it? procedure TEngineData.setEngine(const Value: TEngine); begin assert(value is IEngine); //compiler doesn't like this FEngine := Value; end; Any help would be appreciated. Back to top BRoberts Guest Posted: Fri Aug 01, 2008 5:32 am    Post subject: Re: "is" operator equivalent for interfaces? <masonwheeler (AT) gmail (DOT) com> wrote in message news:bf992d9f-7587-4aca-95f7-3d71cdad88e5 (AT) t12g2000prg (DOT) googlegroups.com... Quote: I'm trying to make sure that any object passed to the write parameter of a property implements a certain interface. The obvious way for checking inheritance, the "is" operator, doesn't seem to work. Is there a different way to do it? procedure TEngineData.setEngine(const Value: TEngine); begin assert(value is IEngine); //compiler doesn't like this FEngine := Value; end; Any help would be appreciated. Interfaces can be bound dynamically at runtime. You can wrap an assignment using the AS operator in a try except and trap the error at runtime. Can you not simply use an iEngine parameter? Back to top        BorlandTalk.com Forum Index -> Delphi (General) All times are GMT Page 1 of 1 Powered by phpBB © 2001, 2006 phpBB Group .