comimpl.h

#ifndef ULT_COMIMPL_H_
#define ULT_COMIMPL_H_

#include <Windows.h>

#ifndef RETURN_IF_FAILED
#define RETURN_IF_FAILED(x) { HRESULT __result_ = (x); if (FAILED(__result_)) return __result_; }
#endif

namespace ult
{
  class UnknownImpl
  {
  public:
    UnknownImpl(): ref_count_(0) {}
  protected:
    ULONG ref_count_;
  };
}

#define ULT_QUERYINTERFACE_BEGIN STDMETHOD(QueryInterface) \
  (REFGUID iid, void **ppobj) {

#define ULT_QUERYINTERFACE_ENTRY(i) else if (iid == IID_ ## i) \
{ *ppobj = (void *)(i *)this; AddRef(); return S_OK; }

#define ULT_QUERYINTERFACE_ENTRY_UNKNOWN(i) if (iid == IID_IUnknown) \
{ *ppobj = (void *)(IUnknown *)(i *)this; AddRef(); return S_OK; }

#define ULT_QUERYINTERFACE_BEGIN2(i) ULT_QUERYINTERFACE_BEGIN \
  ULT_QUERYINTERFACE_ENTRY_UNKNOWN(i) \
  ULT_QUERYINTERFACE_ENTRY(i)

#define ULT_QUERYINTERFACE_END return E_NOINTERFACE; }

#define ULT_ADDREF_RELEASE \
  STDMETHOD_(ULONG, AddRef)() { return ++ref_count_; } \
  STDMETHOD_(ULONG, Release)() { if (--ref_count_ != 0)  \
  return ref_count_; delete this; return 0; }

#define ULT_UNKNOWN_IMP_SPEC(i) \
  ULT_QUERYINTERFACE_BEGIN \
  i \
  ULT_QUERYINTERFACE_END \
  ULT_ADDREF_RELEASE


#define ULT_UNKNOWN_IMP ULT_QUERYINTERFACE_BEGIN \
  ULT_QUERYINTERFACE_ENTRY_UNKNOWN(IUnknown) \
  ULT_QUERYINTERFACE_END \
  ULT_ADDREF_RELEASE

#define ULT_UNKNOWN_IMP1(i) ULT_UNKNOWN_IMP_SPEC( \
  ULT_QUERYINTERFACE_ENTRY_UNKNOWN(i) \
  ULT_QUERYINTERFACE_ENTRY(i) \
  )

#define ULT_UNKNOWN_IMP2(i1, i2) ULT_UNKNOWN_IMP_SPEC( \
  ULT_QUERYINTERFACE_ENTRY_UNKNOWN(i1) \
  ULT_QUERYINTERFACE_ENTRY(i1) \
  ULT_QUERYINTERFACE_ENTRY(i2) \
  )

#define ULT_UNKNOWN_IMP3(i1, i2, i3) ULT_UNKNOWN_IMP_SPEC( \
  ULT_QUERYINTERFACE_ENTRY_UNKNOWN(i1) \
  ULT_QUERYINTERFACE_ENTRY(i1) \
  ULT_QUERYINTERFACE_ENTRY(i2) \
  ULT_QUERYINTERFACE_ENTRY(i3) \
  )

#define ULT_UNKNOWN_IMP4(i1, i2, i3, i4) ULT_UNKNOWN_IMP_SPEC( \
  ULT_QUERYINTERFACE_ENTRY_UNKNOWN(i1) \
  ULT_QUERYINTERFACE_ENTRY(i1) \
  ULT_QUERYINTERFACE_ENTRY(i2) \
  ULT_QUERYINTERFACE_ENTRY(i3) \
  ULT_QUERYINTERFACE_ENTRY(i4) \
  )

#define ULT_UNKNOWN_IMP5(i1, i2, i3, i4, i5) ULT_UNKNOWN_IMP_SPEC( \
  ULT_QUERYINTERFACE_ENTRY_UNKNOWN(i1) \
  ULT_QUERYINTERFACE_ENTRY(i1) \
  ULT_QUERYINTERFACE_ENTRY(i2) \
  ULT_QUERYINTERFACE_ENTRY(i3) \
  ULT_QUERYINTERFACE_ENTRY(i4) \
  ULT_QUERYINTERFACE_ENTRY(i5) \
  )

#endif