C / C++ / MFC

HBRUSH CSubClassedComboBox::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor) 
{

      if (nCtlColor == CTLCOLOR_EDIT)
      {
         //[ASCII 160][ASCII 160][ASCII 160]Edit control
         if (m_CmbEditBox.GetSafeHwnd() == NULL)
            m_CmbEditBox.SubclassWindow(pWnd->GetSafeHwnd());
      }
      else if (nCtlColor == CTLCOLOR_LISTBOX)
      {

         //ListBox control
		  if (m_CmbListBox == NULL)
		  {
			  m_CmbListBox = new CListBoxEx;

			  if (m_CmbListBox->GetSafeHwnd() == NULL)
			  {			  
				  m_CmbListBox->SubclassWindow(pWnd->GetSafeHwnd());
			  }
		  }
      }

	HBRUSH hbr = CComboBox::OnCtlColor(pDC, pWnd, nCtlColor);
	
	return hbr;
}

void CListBoxEx::OnContextMenu(CWnd* pWnd, CPoint point) 
{
	GetParent->TestFn();	
}

void CListBoxEx::OnContextMenu(CWnd* pWnd, CPoint point) 
{
	((CSubClassedComboBox *)GetParent())->TestFn();	//This works and TestFn() of CSubClassedComboBox is called

	GetParent())->TestFn();		//But this doesn't work
}

STDMETHODIMP SomeClass::SomeFunction () 
{ 
    std::string tmp = "This is a std::string"; 
    AnotherFunction(); 
}
 
void SomeClass::AnotherFunction () 
{ 
    std::string tmp = "This is a std::string"; 
} 

CString myfunc()
{
    return CString(_T("a string"));
}
CString myfunc2()
{
    return CString(_T("a string2"));
}

int _tmain(void)
{
    CString tempStr(_T("hello"));
    
    tempStr.Empty();   //Do I need to call this? Or can I ormit this step?
    tempStr= myfunc();

    tempStr.Empty();
    tempStr = myfunc2();
}