anchor.diff:    (tv-sec "tv_sec" :type time-t)
     (tv-nsec "tv_nsec" :type :long))
   
  -(constantenum (kevent-flags :base-type :uint16)
  +(constantenum (kevent-flags :base-type
  +			    #+darwin :uint16
  +			    #+freebsd u-short)
     ((:ev-add "EV_ADD"))
     ((:ev-enable "EV_ENABLE"))
     ((:ev-disable "EV_DISABLE"))
  
positive.code: (include "sys/event.h")
  (include "sys/time.h")
  
  (cstruct kevent64-s "struct kevent64_s"
    (ident "ident" :type :uint64)
    (filter "filter" :type :int16)
  
negative.code:   ((:ev-eof "EV_EOF"))
    ((:ev-error "EV_ERROR")))
  
  (constantenum (kevent-filters :base-type
  			      #+darwin :int16
  			      #+freebsd :short)
    ((:evfilt-read "EVFILT_READ"))
    ((:evfilt-write "EVFILT_WRITE")))
  