:is_null() with use of operator bool().
:is_null() with use of operator bool().

2003-01-27  Murray Cumming  <murrayc@usa.net>

        * Replaced use of RefPtr::is_null() with use of operator bool().

johne53/MB3Gtkmm,johne53/MB3Gtkmm,GNOME/gtkmm,johne53/MB3Gtkmm,GNOME/gtkmm,GNOME/gtkmm,GNOME/gtkmm