#include <gtkmm/treeview.h>
#include <list>

typedef std::list<const Gtk::TreeViewColumn*> list_t;

void f()
{  const Gtk::TreeView *tv=0;
   list_t l=tv->get_columns();
   for (list_t::const_iterator x=l.begin();x!=l.end();++x)
        *x;
}
