Listing 2

// sample_dlg.hpp
struct sample_dlg : 
    wnd_extend<dialog,sample_dlg>, 
    wnd_extend<resizable_wnd,sample_dlg> {
  ...
};
// sample_dlg.cpp
struct sample_dlg_handler : 
    event_handler<sample_dlg_handler, sample_dlg> {
  // ... events here
};