[WinAPI] Problem with an interface...

[Sascha Katzner]

Hi,

I'm not sure if this is a bug in the way D handles interfaces or if I 
misunderstand something. I was trying to translate the Direct3D 10 
headers for the Windows API project: 
http://www.dsource.org/projects/bindings/browser/trunk/win32/directx

I have a Windows function (GetTechniqueByName), which returns a pointer 
to an interface (which in D results to a simple interface, because in D 
interfaces are allready reference types).

> ID3D10EffectTechnique GetTechniqueByName(LPCSTR Name);
> 
> interface ID3D10EffectTechnique {
> 	extern(Windows) :
> 	BOOL IsValid();
> 	HRESULT GetDesc(D3D10_TECHNIQUE_DESC* pDesc);
> 	ID3D10EffectVariable GetAnnotationByIndex(UINT Index);
> 	ID3D10EffectVariable GetAnnotationByName(LPCSTR Name);
> 	ID3D10EffectPass GetPassByIndex(UINT Index);
> 	ID3D10EffectPass GetPassByName(LPCSTR Name);
> 	HRESULT ComputeStateBlockMask(D3D10_STATE_BLOCK_MASK* pStateBlockMask);
> }

If I try subsequently to call a function from this interface something 
very strange happens, the call results in the very next function from 
the interface declaration being called. For example if I call 
"technique.IsValid()" D calls GetDesc(), which results in an access 
violation.

This behavior appears only to happen with interfaces which are NOT 
derived from IUnknown.

I have attached a stripped down version of my source attached to this 
posting and a compiled version with debug info can be found at: 
http://sascha.katzner.de/misc/interface.exe

LLAP,
Sascha Katzner
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