anchor.diff:  ;;       } ifr_ifru;
   ;;   };
   
  -;; (defcunion ifreq-data
  -;;   (addr (:struct sockaddr-in))
  -;;   (flags :uint16)
  -;;   (ivalue :int32)
  -;;   (mtu :int32))
  +
  +;; struct ifmap {
  +;;     unsigned long   mem_start;
  +;;     unsigned long   mem_end;
  +;;     unsigned short  base_addr;
  +;;     unsigned char   irq;
  +;;     unsigned char   dma;
  +;;     unsigned char   port;
  +;; };
   
   (defcstruct ifmap
     (mem_start :ulong)
  
positive.code:   (fd :int32)
    (addr :pointer)
    (len :pointer))
  (defun socket-peer (fd)
    (with-foreign-objects ((addr :uint32 +sockaddr-storage+)
                           (len :uint32))
  
negative.code: ;; void freeifaddrs(struct ifaddrs *ifa);
  (defcfun (%freeifaddrs "freeifaddrs") :void
    (ifaddrs :pointer))
          
  ;; struct ifreq
  ;;   {
  