interfaces and such

[Chris Nicholson-Sauls]

On Friday, 24 August 2012 at 14:15:28 UTC, Steven Schveighoffer 
wrote:
> On Fri, 27 Jul 2012 12:48:59 -0400, David Nadlinger 
> <see at klickverbot.at>
> wrote:
>
>> On Friday, 27 July 2012 at 14:56:18 UTC, Gor Gyolchanyan wrote:
>>> I have a small question: why aren't interfaces implicitly 
>>> convertible to
>>> Object?
>>
>> Not all interfaces »originate« from D objects, they can also 
>> be COM interfaces. Using (cast(Object)foo) should work if foo 
>> is really an Object.
>
> All Com interfaces inherit from IUnknown.  This is statically 
> known.
>
> The idea that we cannot tell which interfaces are COM and which 
> are normal
> is a myth.
>
> There is no reason why interfaces (that aren't COM) shouldn't be
> implicitly castable to Object.
>
> -Steve

Technically true, however COM is not the only example of foreign 
objects used via interfaces.  The (limited) C++ compatibility, 
for example, works this way.