_SUBWIN
int flags = _SUBWIN;
nwin->_flags = tmp._flags & ~(_SUBWIN);
nwin->_flags = win->_flags & ~_SUBWIN;
if (!(win->_flags & _SUBWIN)) {
#define is_subwin(win) (NCURSES_OK_ADDR(win) ? ((win)->_flags & _SUBWIN) != 0 : FALSE)
#define IS_SUBWIN(w) ((w)->_flags & _SUBWIN)