typeid() broken for interfaces?

[foobar]

On Monday, 3 December 2012 at 20:59:24 UTC, Walter Bright wrote:
> On 12/4/2012 2:52 AM, Jacob Carlborg wrote:
>> Note, I'm not saying that an interface should be implicitly 
>> converted to
>> any class, only to Object.
>
>
> But not all interfaces come from Objects.

IMO this is a design mistake - the special case is preferred over 
the common case which goes against the D philosophy of making the 
common case easy and the special case possible.

All COM instances are known at _compile_time_ as they're all 
required to inherit from a special IUnknown interface so the 
compiler _knows_ if indeed an interface represents a COM instance 
or not. This can be used to handle this special case differently.

Interface i = new Class();
Object o = i; // should work for regular interfaces

The compiler can issue a compile-time error if i is COM since 
this is known at compile type.