SCM_PORT_BUFFER_ROOM  167 ext/charconv/charconv.c             outroom = SCM_PORT_BUFFER_ROOM(port);
SCM_PORT_BUFFER_ROOM  194 ext/charconv/charconv.c     outroom = SCM_PORT_BUFFER_ROOM(port);
SCM_PORT_BUFFER_ROOM  536 src/port.c         if (min <= 0) min = SCM_PORT_BUFFER_ROOM(p);
SCM_PORT_BUFFER_ROOM  538 src/port.c             toread = SCM_PORT_BUFFER_ROOM(p);