two-way DDX_Text update

I hate MFC(Too personal. I should delete, shouldn’t I), but quite a lot MFC-applications still work nicely now.
I am fixing a bug now and get trapped for this minor problem. Spend 30 minutes to figure that out, OMG!!!!

DDX_Text(pDX, IDC_EDIT_NAME, m_strName);
UpdateData(TRUE) or UpdateData() // From control to string
UpdateData(FALSE) // From string to control

Can boolean be function parameters??
see OldNewThing