Like getClass()

[Sergey Gromov]

Sat, 27 Sep 2008 19:21:56 -0400,
Christopher Wright wrote:
> Sergey Gromov wrote:
> > Sat, 27 Sep 2008 19:50:18 +0200,
> > torhu wrote:
> >> obj.classinfo doesn't work the way you'd expect with an interface, but 
> >> it works when you've got an object:
> >>
> >> writefln((cast(Object)thing).classinfo.name);
> > 
> > Thanks for the tip!  It seems like classinfo of an interface contains 
> > information about the most derived interface implemented in an object:
> > 
> > interface a {}
> > interface aa : a {}
> > class A : aa {}
> > void main() {
> >     writefln((cast(a) new A).classinfo.name);
> > }
> > 
> > prints "test.aa".  Though this functionality is of questionable 
> > usefulness (has anybody used it for something?) and besides it's broken:
> > 
> > interface a {}
> > interface aa : a {}
> > class A : a, aa {}
> > void main() {
> >     writefln((cast(a) new A).classinfo.name);
> > }
> > 
> > prints "test.a" even though A implements the "aa" interface as well.
> 
> 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.