So I found it. Its actually your fault.
IXAudio2Voice isn't a COM interface. That means it should _not_ inherit
from IUnkown. But if it isn't a COM interface it can't be a regular D
interface either, because if it is a regular D-Interface it will not
have a v-table layout that conforms with C++. That means you have to put
"extern(C++)" in front of IXAudio2Voice to make it work.
So to make stuff work you should change
interface IXAudio2Voice : IUnknown
to
extern(C++) interface IXAudio2Voice
Then everything works fine.
Tip for the future: Using the "Microsoft Symbol Server" and the Visual
Studio Debugger you can easily verify if your COM interfaces call the
correct methods or if you messed up the declarations.
Kind Regards
Benjamin Thaut
