comutil.h

本源码是vc环境下的usb程序

	return *this;
}

// Assign a double creating either a VT_R8 VARIANT, or a VT_DATE
// VARIANT (VT_R8 is the default)
//
inline _variant_t& _variant_t::operator=(double dblSrc) throw(_com_error)
{
	if (V_VT(this) == VT_R8) {
		V_R8(this) = dblSrc;
	}
	else if(V_VT(this) == VT_DATE) {
		V_DATE(this) = dblSrc;
	}
	else {
		// Clear the VARIANT and create a VT_R8
		//
		Clear();

		V_VT(this) = VT_R8;
		V_R8(this) = dblSrc;
	}

	return *this;
}

// Assign a CY creating a VT_CY VARIANT
//
inline _variant_t& _variant_t::operator=(const CY& cySrc) throw(_com_error)
{
	if (V_VT(this) != VT_CY) {
		// Clear the VARIANT and create a VT_CY
		//
		Clear();

		V_VT(this) = VT_CY;
	}

	V_CY(this) = cySrc;

	return *this;
}

// Assign a const _bstr_t& creating a VT_BSTR VARIANT
//
inline _variant_t& _variant_t::operator=(const _bstr_t& bstrSrc) throw(_com_error)
{
	// Clear the VARIANT (This will SysFreeString() any previous occupant)
	//
	Clear();

	if (!bstrSrc) {
        V_VT(this) = VT_BSTR;
		V_BSTR(this) = NULL;
	}
	else {
		BSTR bstr = static_cast<wchar_t*>(bstrSrc);
		wchar_t*tmp = ::SysAllocStringByteLen(reinterpret_cast<char*>(bstr),
											   ::SysStringByteLen(bstr));

		if (tmp == NULL) {
			_com_issue_error(E_OUTOFMEMORY);
		} else {
            V_VT(this) = VT_BSTR;
    		V_BSTR(this) = tmp;
        }
	}

	return *this;
}

// Assign a const wchar_t* creating a VT_BSTR VARIANT
//
inline _variant_t& _variant_t::operator=(const wchar_t* pSrc) throw(_com_error)
{
	// Clear the VARIANT (This will SysFreeString() any previous occupant)
	//
	Clear();

	if (pSrc == NULL) {
        V_VT(this) = VT_BSTR;
		V_BSTR(this) = NULL;
	}
	else {
		wchar_t*tmp = ::SysAllocString(pSrc);

		if (tmp == NULL) {
			_com_issue_error(E_OUTOFMEMORY);
		} else {
            V_VT(this) = VT_BSTR;
            V_BSTR(this) = tmp;
        }
	}

	return *this;
}

// Assign a const char* creating a VT_BSTR VARIANT
//
inline _variant_t& _variant_t::operator=(const char* pSrc) throw(_com_error)
{
	// Clear the VARIANT (This will SysFreeString() any previous occupant)
	//
	Clear();

	V_VT(this) = VT_BSTR;
	V_BSTR(this) = _com_util::ConvertStringToBSTR(pSrc);

	if (V_BSTR(this) == NULL && pSrc != NULL) {
		_com_issue_error(E_OUTOFMEMORY);
	}

	return *this;
}

// Assign an IDispatch* creating a VT_DISPATCH VARIANT
//
inline _variant_t& _variant_t::operator=(IDispatch* pSrc) throw(_com_error)
{
	// Clear the VARIANT (This will Release() any previous occupant)
	//
	Clear();

	V_VT(this) = VT_DISPATCH;
	V_DISPATCH(this) = pSrc;

	// Need the AddRef() as VariantClear() calls Release()
	//
	V_DISPATCH(this)->AddRef();

	return *this;
}

// Assign a bool creating a VT_BOOL VARIANT
//
inline _variant_t& _variant_t::operator=(bool bSrc) throw(_com_error)
{
	if (V_VT(this) != VT_BOOL) {
		// Clear the VARIANT and create a VT_BOOL
		//
		Clear();

		V_VT(this) = VT_BOOL;
	}

	V_BOOL(this) = (bSrc ? VARIANT_TRUE : VARIANT_FALSE);

	return *this;
}

// Assign an IUnknown* creating a VT_UNKNOWN VARIANT
//
inline _variant_t& _variant_t::operator=(IUnknown* pSrc) throw(_com_error)
{
	// Clear VARIANT (This will Release() any previous occupant)
	//
	Clear();

	V_VT(this) = VT_UNKNOWN;
	V_UNKNOWN(this) = pSrc;

	// Need the AddRef() as VariantClear() calls Release()
	//
	V_UNKNOWN(this)->AddRef();

	return *this;
}

// Assign a DECIMAL creating a VT_DECIMAL VARIANT
//
inline _variant_t& _variant_t::operator=(const DECIMAL& decSrc) throw(_com_error)
{
	if (V_VT(this) != VT_DECIMAL) {
		// Clear the VARIANT
		//
		Clear();
	}

	// Order is important here! Setting V_DECIMAL wipes out the entire VARIANT
	V_DECIMAL(this) = decSrc;
	V_VT(this) = VT_DECIMAL;

	return *this;
}

// Assign a BTYE (unsigned char) creating a VT_UI1 VARIANT
//
inline _variant_t& _variant_t::operator=(BYTE bSrc) throw(_com_error)
{
	if (V_VT(this) != VT_UI1) {
		// Clear the VARIANT and create a VT_UI1
		//
		Clear();

		V_VT(this) = VT_UI1;
	}

	V_UI1(this) = bSrc;

	return *this;
}

// Assign a LONGLONG creating a VT_I8 VARIANT
//
inline _variant_t& _variant_t::operator=(LONGLONG llSrc) throw(_com_error)
{
	if (V_VT(this) != VT_I8) {
		// Clear the VARIANT and create a VT_I8
		//
		Clear();

		V_VT(this) = VT_I8;
	}

	V_I8(this) = llSrc;

	return *this;
}

// Assign a ULONGLONG creating a VT_UI8 VARIANT
//
inline _variant_t& _variant_t::operator=(ULONGLONG ullSrc) throw(_com_error)
{
	if (V_VT(this) != VT_UI8) {
		// Clear the VARIANT and create a VT_UI8
		//
		Clear();

		V_VT(this) = VT_UI8;
	}

	V_UI8(this) = ullSrc;

	return *this;
}

//////////////////////////////////////////////////////////////////////////////////////////
//
// Comparison operations
//
//////////////////////////////////////////////////////////////////////////////////////////

// Compare a _variant_t against a const VARIANT& for equality
//
inline bool _variant_t::operator==(const VARIANT& varSrc) const throw()
{
	return *this == &varSrc;
}

// Compare a _variant_t against a const VARIANT* for equality
//
inline bool _variant_t::operator==(const VARIANT* pSrc) const throw()
{
	if (this == pSrc) {
		return true;
	}

	//
	// Variants not equal if types don't match
	//
	if (V_VT(this) != V_VT(pSrc)) {
		return false;
	}

	//
	// Check type specific values
	//
	switch (V_VT(this)) {
		case VT_EMPTY:
		case VT_NULL:
			return true;

		case VT_I2:
			return V_I2(this) == V_I2(pSrc);

		case VT_I4:
			return V_I4(this) == V_I4(pSrc);

		case VT_I8:
			return V_I8(this) == V_I8(pSrc);

		case VT_R4:
			return V_R4(this) == V_R4(pSrc);

		case VT_R8:
			return V_R8(this) == V_R8(pSrc);

		case VT_CY:
			return memcmp(&(V_CY(this)), &(V_CY(pSrc)), sizeof(CY)) == 0;

		case VT_DATE:
			return V_DATE(this) == V_DATE(pSrc);

		case VT_BSTR:
			return (::SysStringByteLen(V_BSTR(this)) == ::SysStringByteLen(V_BSTR(pSrc))) &&
					(memcmp(V_BSTR(this), V_BSTR(pSrc), ::SysStringByteLen(V_BSTR(this))) == 0);

		case VT_DISPATCH:
			return V_DISPATCH(this) == V_DISPATCH(pSrc);

		case VT_ERROR:
			return V_ERROR(this) == V_ERROR(pSrc);

		case VT_BOOL:
			return V_BOOL(this) == V_BOOL(pSrc);

		case VT_UNKNOWN:
			return V_UNKNOWN(this) == V_UNKNOWN(pSrc);

		case VT_DECIMAL:
			return memcmp(&(V_DECIMAL(this)), &(V_DECIMAL(pSrc)), sizeof(DECIMAL)) == 0;

		case VT_UI1:
			return V_UI1(this) == V_UI1(pSrc);

		default:
			_com_issue_error(E_INVALIDARG);
			// fall through
	}

	return false;
}

// Compare a _variant_t against a const VARIANT& for in-equality
//
inline bool _variant_t::operator!=(const VARIANT& varSrc) const throw()
{
	return !(*this == &varSrc);
}

// Compare a _variant_t against a const VARIANT* for in-equality
//
inline bool _variant_t::operator!=(const VARIANT* pSrc) const throw()
{
	return !(*this == pSrc);
}

//////////////////////////////////////////////////////////////////////////////////////////
//
// Low-level operations
//
//////////////////////////////////////////////////////////////////////////////////////////

// Clear the _variant_t
//
inline void _variant_t::Clear() throw(_com_error)
{
	_com_util::CheckError(::VariantClear(this));
}

inline void _variant_t::Attach(VARIANT& varSrc) throw(_com_error)
{
	//
	// Free up previous VARIANT
	//
	Clear();

	//
	// Give control of data to _variant_t
	//
	memcpy(this, &varSrc, sizeof(varSrc));
	V_VT(&varSrc) = VT_EMPTY;
}

inline VARIANT _variant_t::Detach() throw(_com_error)
{
	VARIANT varResult = *this;
	V_VT(this) = VT_EMPTY;

	return varResult;
}

// Change the type and contents of this _variant_t to the type vartype and
// contents of pSrc
//
inline void _variant_t::ChangeType(VARTYPE vartype, const _variant_t* pSrc) throw(_com_error)
{
	//
	// If pDest is NULL, convert type in place
	//
	if (pSrc == NULL) {
		pSrc = this;
	}

	if ((this != pSrc) || (vartype != V_VT(this))) {
		_com_util::CheckError(::VariantChangeType(static_cast<VARIANT*>(this),
												  const_cast<VARIANT*>(static_cast<const VARIANT*>(pSrc)),
												  0, vartype));
	}
}

inline void _variant_t::SetString(const char* pSrc) throw(_com_error)
{
	//
	// Free up previous VARIANT
	//
	Clear();

	V_VT(this) = VT_BSTR;
	V_BSTR(this) = _com_util::ConvertStringToBSTR(pSrc);

	if (V_BSTR(this) == NULL && pSrc != NULL) {
		_com_issue_error(E_OUTOFMEMORY);
	}
}

//////////////////////////////////////////////////////////////////////////////////////////
//
// Destructor
//
//////////////////////////////////////////////////////////////////////////////////////////

inline _variant_t::~_variant_t() throw(_com_error)
{
	_com_util::CheckError(::VariantClear(this));
}

//////////////////////////////////////////////////////////////////////////////////////////
//
// Mutually-dependent definitions
//
//////////////////////////////////////////////////////////////////////////////////////////

// Construct a _bstr_t from a const _variant_t&
//
inline _bstr_t::_bstr_t(const _variant_t &var) throw(_com_error)
	: m_Data(NULL)
{
	if (V_VT(&var) == VT_BSTR) {
		*this = V_BSTR(&var);
		return;
	}

	_variant_t varDest;

	varDest.ChangeType(VT_BSTR, &var);

	*this = V_BSTR(&varDest);
}

// Assign a const _variant_t& to a _bstr_t
//
inline _bstr_t& _bstr_t::operator=(const _variant_t &var) throw(_com_error)
{
	if (V_VT(&var) == VT_BSTR) {
		*this = V_BSTR(&var);
		return *this;
	}

	_variant_t varDest;

	varDest.ChangeType(VT_BSTR, &var);

	*this = V_BSTR(&varDest);

	return *this;
}

extern _variant_t vtMissing;

#ifndef _USE_RAW
#define bstr_t _bstr_t
#define variant_t _variant_t
#endif

#if _MSC_VER >= 1200
#pragma warning(pop)
#endif

#endif	// _INC_COMUTIL