# from 5.6.1's Socket.pm on Linux 2.4
sub AUTOLOAD {
    my($constname);
    ($constname = $AUTOLOAD) =~ s/.*:://;
    my $val = constant($constname, @_ ? $_[0] : 0);
    if ($! != 0) {
        my ($pack,$file,$line) = caller;
        croak "Your vendor has not defined Socket macro $constname, used";
    }
    eval "sub $AUTOLOAD () { $val }";
    goto &$AUTOLOAD;
}