通用FileMapping类

#define FILEMAPPINGNAME L"xxx"
template <typename _T>
class CMemroySharePtr
{
public:
	CMemroySharePtr()
		:m_hMappingHdr(NULL)
		,m_pMappingFile(NULL)
	{
		if ((m_hMappingHdr == NULL) && (m_pMappingFile == NULL))
		{
			m_hMappingHdr = CreateFileMapping(
				INVALID_HANDLE_VALUE, 
				NULL, 
				PAGE_READWRITE, 
				0, 
				sizeof(_T), 
				FILEMAPPINGNAME);
			if ((m_hMappingHdr != NULL) && (GetLastError() == ERROR_ALREADY_EXISTS))
			{
				m_pMappingFile = (_T*)MapViewOfFile(m_hMappingHdr,FILE_MAP_ALL_ACCESS,0,0,0);
			}
			else if (m_hMappingHdr != NULL)
			{
				m_pMappingFile = (_T*)MapViewOfFile(m_hMappingHdr,FILE_MAP_ALL_ACCESS,0,0,0);
				if (m_pMappingFile != NULL)
				{
					ZeroMemory(m_pMappingFile, sizeof(_T));
					_T temp;
					*m_pMappingFile = temp;
				}
			}
		}
	}
	~CMemroySharePtr()
	{
		if (m_pMappingFile != NULL)
		{
			UnmapViewOfFile(m_pMappingFile);
			m_pMappingFile = NULL;
		}
		if (m_hMappingHdr != NULL)
		{
			CloseHandle(m_hMappingHdr);
			m_hMappingHdr = NULL;
		}
	}
	_T* const operator->() throw()
	{
		return m_pMappingFile;
	}
	operator bool()
	{
		return (m_pMappingFile != NULL)?true:false;
	}
private:
	HANDLE	m_hMappingHdr;
	_T*		m_pMappingFile;
};