sub TIEARRAY {
    my($class, $bits, $vec) = @_;
    no strict 'refs';
    my $self = bless [\%{$class.'::FIELDS'}], $class;
    
    $self->{bits} = $bits;
    $self->{vec}  = ref $vec ? $vec : \$vec;
    $self->{size} = _BYTES2IDX($self, length ${$self->{vec}});

    return $self;
}