Multidevice ASIO output plugin for WinAMP

//
// COMAutoPtrWrapper module
// ------------------------
//
//  Provides a simple wrapper around various/known COM smart pointers and raw
// interface pointers to provide a single interface.
//  (currently provides only the minimum required for the Wasiona project)
//
////////////////////////////////////////////////////////////////////////////////

#pragma once

#ifdef TINY_ATL
    // (todo) this is duplicated from WTL.h (remove the duplication).
    #define ATLENSURE ATLVERIFY
    #define AtlThrow exit
#endif

#define _WIN32_DCOM // Required to be able to use COM.


// "Native" _com_ptr_t<>.
#include "comip.h"
#include "comdef.h"

// ATL::CComPtr<>.
#include "atlcomcli.h"

#include <type_traits>


////////////////////////////////////////////////////////////////////////////////
//
//  COMAutoPtrWrapper
//  -----------------
//
// (todo) add a "direct" getter for the BaseCOMInterface (which bypasses any
//        BaseCOMPtr checks).
//
////////////////////////////////////////////////////////////////////////////////

template <class BaseCOMPtr, class BaseCOMInterface>
class COMAutoPtrWrapper
{
public:
    COMAutoPtrWrapper() : baseCOMPtr_() {}
    COMAutoPtrWrapper( BaseCOMPtr const * const baseCOMPtr ) : baseCOMPtr_( baseCOMPtr ) { addRefIfNecessary(); }
    COMAutoPtrWrapper( COMAutoPtrWrapper const & source ) : baseCOMPtr_( source.baseCOMPtr_ ) { addRefIfNecessary(); }
    ~COMAutoPtrWrapper() { releaseIfNecessary(); }

    BaseCOMInterface & operator *() const;
    BaseCOMInterface * operator->() const { return &operator*(); }

    COMAutoPtrWrapper & operator=( COMAutoPtrWrapper const & other );

    unsigned long release();

    static COMAutoPtrWrapper createInstance( REFCLSID rclsid, REFIID riid, DWORD dwClsContext = CLSCTX_INPROC_SERVER );

    BaseCOMPtr & base() { return baseCOMPtr_; }

    typedef BaseCOMInterface * (COMAutoPtrWrapper::*unspecified_bool_type)() const;
    operator unspecified_bool_type() const { return baseCOMPtr_ ? &COMAutoPtrWrapper::operator-> : 0; }

private:
    void addRefIfNecessary();
    void releaseIfNecessary();

private:
    BaseCOMPtr baseCOMPtr_;
};


#include "COMSmartPTrWrapper.inl"