Generic classes templates with COM Interfaces

  • Thread starter Thread starter Arathij
  • Start date Start date
A

Arathij

Guest
Hi

this is my generic class with templates when I try to query using QueryInterface

here the spDispatch is always NULL this doesn't work in VS2017 with windows server 2016 please help in resolving this , tlb is compiled with MIDL in VS2017 no difference

though this works fine with VS2015 and windows server 2012


CComPtr<IDispatch> spDispatch;
m_obj->QueryInterface (IID_IDispatch, (void**)&spDispatch); // here spDispatch is always NULL

CLASS

template<class T0, class... T>
struct GetFirstParameterPackType { typedef T0 Value; };

template<class... Interfaces>
class ScriptHostObjectBase : public Interfaces..., public CComObjectRootEx<CComMultiThreadModelNoCS>
{
private:
typedef ScriptHostObjectBase<Interfaces...> Self;
typedef std::function<IDispatch* (Self*)> InterfaceCastFunc;
typedef typename GetFirstParameterPackType<Interfaces...>::Value FirstInterface;
static const int InterfaceCount = sizeof...(Interfaces);
static const GUID InterfaceGuids[InterfaceCount];
static const InterfaceCastFunc CastFuncs[InterfaceCount];
static ITypeInfo* TypeInfoCache[InterfaceCount];

struct Entry
{
UINT interfaceIdx;
DISPID dispid;
};

const DISPID BaseVirtualDispID = 0x40000000;
const DISPID MaxVirtualDispID = 0x50000000;
std::vector<Entry> m_vecDispIDs;


BEGIN_COM_MAP(ScriptHostObjectBase)
COM_INTERFACE_ENTRY2(IDispatch, FirstInterface)
END_COM_MAP()
;;;;;;
}

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