C / C++ / MFC

typedef unsigned (__stdcall *PCBTHREAD_FUNCTION)(void *);

class CBThread : public CBHandle
{
public:
	virtual unsigned ThreadMain() = 0;

public:
	CBThread()	{}

	BOOL Create(
		PCBTHREAD_FUNCTION pThread,
		LPVOID pParam = NULL,
		unsigned stackSize = 0,
		BOOL startSuspended = FALSE,
		int priority = -1);

	BOOL Create(
		unsigned stackSize = 0,
		BOOL startSuspended = FALSE,
		int priority = -1);
};

static unsigned __stdcall CBThreadThread(CBThread *pClass)
{
	return pClass->ThreadMain(); // ThreadMain is a the virtual public function in the CBThread class
}

BOOL CBThread::Create(
	PCBTHREAD_FUNCTION pThread,
	LPVOID pParam,
	unsigned stackSize,
	BOOL startSuspended,
	int priority)
{
	if (IsRunning())
		return FALSE;

	unsigned threadID; // it's useless so throw it away and save space
	if ((m_handle = (HANDLE) _beginthreadex(NULL, stackSize, pThread, pParam, startSuspended, &threadID)) != NULL)
	{
		if (priority >= 0)
			SetPriority(priority);
		return TRUE;
	}
	return FALSE;
}

BOOL CBThread::Create(
	unsigned stackSize,
	BOOL startSuspended,
	int  priority)
{
	return Create((PCBTHREAD_FUNCTION)CBThreadThread, this, stackSize, startSuspended, priority);
}

class Singleton {
    public:
        static Singleton* Instance();
    protected:
        Singleton();
    private:
        static Singleton* _instance;
    };

The corresponding implementation is

    Singleton* Singleton::_instance = 0;
    
    Singleton* Singleton::Instance () {
        if (_instance == 0) {
            _instance = new Singleton;
        }
        return _instance;
    }

BEGIN_MESSAGE_MAP(CMyDialog, CDialog)
	ON_NOTIFY(NM_DBLCLK, IDC_SOMECONTROL, OnDblclkSomeControl)
END_MESSAGE_MAP()

void CMyDialog::OnDblclkSomeControl(NMHDR* pNMHDR, LRESULT* pResult) 
{
	NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
	int item_clicked = pNMListView->iItem;	

	if(item_clicked != -1)
	{
		DoSomething();
	}
	
	*pResult = 0;
}

afx_msg void OnDblclkSomeControl(NMHDR* pNMHDR, LRESULT* pResult);