anchor.diff:    ((:enonet "ENONET") :optional t)
     ((:enobufs "ENOBUFS"))
     ((:eopnotsupp "EOPNOTSUPP")))
  ++
   
   ;;; open()
  +
   (constant (o-rdonly "O_RDONLY"))
   (constant (o-wronly "O_WRONLY"))
   (constant (o-rdwr "O_RDWR"))
  
positive.code: (constant (map-private "MAP_PRIVATE") :documentation "mmap: private mapping")
  (constant (map-fixed   "MAP_FIXED")   :documentation "mmap: map at location")
  (constant (map-failed  "MAP_FAILED")  :documentation "mmap: failure")
  
  ;;; poll()
  
  
negative.code:   "UNIX time specification in seconds and nanoseconds."
    (sec  "tv_sec"  :type time-t)
    (nsec "tv_nsec" :type :long))
  
  
  ;;; from sys/select.h
  
  (cstruct timeval "struct timeval"
    "UNIX time specification in seconds and microseconds."
    (sec  "tv_sec"  :type time-t)
    (usec "tv_usec" :type suseconds-t))
  
  
  ;;; from sys/stat.h
  
  (ctype dev-t "dev_t")
  (ctype ino-t "ino_t")
  