C / C++ / MFC

#include <iostream>
using namespace std;

const int size = 3;
class vector{
    int v[size];

public:
    vector();                                                                                                //constructor num vector
    vector(int *x);                                                                                          //constructor from arr
    friend vector operator * (int a, vector b);                                                              //friend 1
    friend vector operator * (vector b, int a);                                                              //friend 2
    friend istream & operator >> (istream &, vector &);      //what is this ??
    friend ostream & operator << (ostream &, vector &);        
};

Quote:

friend istream & operator >> (istream &, vector &);

class MyClass : public CScrollView
{

    public : 
             DECLARE_MESSAGE_MAP();
             void OnButtonSelect();
             void Init();
             CButton m_button;

}

// In .cpp file

BEGIN_MESSAGE_MAP(MyClass , CScrollView)

        ON_COMMAND(ID_FILE_PRINT, OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, OnFilePrintPreview)
        ON_BN_CLICKED(1010, OnButtonSelect)

END_MESSAGE_MAP()

MyClass::Init()
{
  m_button.Create(_T("Hi"),, BS_PUSHBUTTON, CRect(0, 0, 80, 20), m_cdRadViewer, 1010);
  m_button.ShowWindow(SW_SHOW);
}

MyClass:OnButtonSelect()
{
  AfxMessageBox(_T("hi, button Clicked"));
}

class CTabClass : public CTabView
{


        void OnCreate()
        {
	      m_CView = RUNTIME_CLASS(CDocumentView);
	      AddView(m_CView,_T("Tab1"));
	      AddView(m_CView,_T("Tab2")); //this creating 2nd tab but throwing assertions and 
                                           //finally crashing while accessing it.	
        }
}

// header
// Generated message map functions
protected:
	afx_msg void OnFilePrintPreview();
	afx_msg void OnRButtonUp(UINT nFlags, CPoint point);
	afx_msg void OnContextMenu(CWnd* pWnd, CPoint point);
	afx_msg void OnNMRDblclkTree1(NMHDR *pNMHDR, LRESULT *pResult);
	DECLARE_MESSAGE_MAP()

BEGIN_MESSAGE_MAP(CTestTreeView, CFormView)
	ON_NOTIFY(NM_RDBLCLK, IDC_TREE1, &CTestTreeView::OnNMRDblclkTree1)
END_MESSAGE_MAP()

....
....
void CTestTreeView::OnNMRDblclkTree1(NMHDR *pNMHDR, LRESULT *pResult)
{
	// TODO: Add your control notification handler code here

	MessageBox(_T("Aha"));

	*pResult = 0;
}