Like getClass()

[Sergey Gromov]

Mon, 29 Sep 2008 01:12:45 +0400,
Denis Koroskin wrote:
> On Sun, 28 Sep 2008 04:42:15 +0400, Sergey Gromov <snake.scaly at gmail.com>  
> wrote:
> 
> > Sat, 27 Sep 2008 19:21:56 -0400,
> > Christopher Wright wrote:
> >> Since .classinfo is essentially a virtual call, and interface vtbls are
> >> filled from the class's vtbl, it shouldn't in theory be terribly
> >> difficult to change this. Of course, I'd have to check the dmd source to
> >> be sure.
> >
> > I'd say it's a bug.  Classinfo is for runtime class, and runtime class
> > can never be an interface.
> 
> Do all IUknown interface instances have classinfo member? That's not a bug  
> if they don't. That's the same reason why interfaces can't be casted to  
> Object.

IUnknown cannot be a D interface because it does not comply with D ABI.  
IUnknown cannot have any .classinfo.  Iunknown cannot be cast to 
anything except by the means of QueryInterface().  You've chosen the 
wrong example.

Only D interfaces can have .classinfo.  You cannot instantiate a D 
interface, only a class.  Therefore whenever you get a reference it's 
either null or refers to an instantiated *class* which definitely has 
its one and only correct .classinfo.