Is it time to deprecate COM compatibility through D interfaces?

[Steven Schveighoffer]

Given that structs have become extremely powerful, and with the advent of  
opDispatch, would it be possible to deprecate supporting COM via D  
interfaces in favor of a library solution?

There are some crappy drawbacks for having interface be dual-purposed:

- Although 99.9% of interfaces are actually instances of Object, you can't  
call Object functions directly on an interface.  This includes opEquals,  
opCmp, toString and friends.
- They are not implicitly castable to Object.
- There is no centralized base interface, so there is no argument type you  
can use that can accept any interface.  For instance, if you wanted to do  
some runtime reflection to determine an interface's methods or something.
- All these drawbacks are absolutely pointless on non-Microsoft OSes.

We are in the process of getting rid of builtin complex types in favor of  
library types -- can we do something similar?

I admit I am not familiar with COM, except my few experiences with it I  
hated :)  Does anyone actually use D interfaces to represent COM objects?   
What would the drawbacks be of interfacing COM objects via compile-time  
generated structs that do the busy work?

Another possibility is simply making normal interfaces derive from Object,  
and COM interfaces not.  I think this has been discussed before.

-Steve