[WinAPI] Problem with an interface...

[Sascha Katzner]

Sascha Katzner wrote:
> But IUnknown itself is declared as an D interface:
> 
> com.d:
>> interface IUnknown
>> {
>>     HRESULT QueryInterface(IID* riid, void** pvObject);
>>     ULONG AddRef();
>>     ULONG Release();
>> } 
> 
> ...or is this only some kind of false front, and the real implementation 
>  is hidden behind some compiler magic?

I've found something...

internal\object.d:
> /**
>  * Information about an interface.
>  * A pointer to this appears as the first entry in the interface's vtbl[].
>  */
> struct Interface
> {
>     ClassInfo classinfo;	/// .classinfo for this interface (not for containing class)
>     void *[] vtbl;
>     int offset;			/// offset to Interface 'this' from Object 'this'
> }

It seems this explains exactly why the next function is called (because 
D expects an additional first entry which Windows doesn't deliver), when 
using a normal D interface instead of something derived from IUnknown. 
What it doesn't explain is, why IUnknown interfaces doesn't have this 
problem?!?

LLAP,
Sascha Katzner