   public init() {
     ai_flags     = 0 // AI_CANONNAME, AI_PASSIVE, AI_NUMERICHOST
     ai_family    = AF_UNSPEC // AF_INET or AF_INET6 or AF_UNSPEC
-    ai_socktype  = SOCK_STREAM
+    ai_socktype  = sys_SOCK_STREAM
     ai_protocol  = 0   // or IPPROTO_xxx for IPv4
     ai_addrlen   = 0   // length of ai_addr below
     ai_canonname = nil // UnsafePointer<Int8>

    // how to refer to self?
  
  public init() {
    sin_len    = sockaddr_in.size
    sin_family = sa_family_t(sockaddr_in.domain)
    sin_port   = 0
    sin_addr   = INADDR_ANY

  public static var size   = __uint8_t(sizeof(sockaddr_in6))
  
  public init() {
#if os(Linux) // no sin_len on Linux
#else
    sin6_len      = sockaddr_in6.size
#endif
    sin6_family   = sa_family_t(sockaddr_in.domain)
    sin6_port     = 0
    sin6_flowinfo = 0
