Implementierung

my %attributes = (
                 login   => undef,
                 uid     => undef,
                 gid     => undef,
                 err_msg => '',
                 err_cnt => 0,
                 )


sub new {
    my $this  = shift;

    # No Inheritance
    my $class = ref($this) || $this;
    my $self  = {
                 _permitted => {},
                 %attributes,
                };
    bless $self, $class;
    
    foreach my $attrib (keys %attributes) {
        $self->{_permitted}->{$attrib} = $attributes{$attrib};
    }
    $self->_init();
    return $self;
}

sub AUTOLOAD {
    my $self = shift;
    my $type = ref($self) || croak "$self is not an object";
    my $name = $AUTOLOAD;
    $name =~ s/.*://;   # strip fully-qualified portion
    unless (exists $self->{_permitted}->{$name} ) {
        croak "Can't access `$name' field in object of class $type";
    } 
    if (@_) { return $self->{$name} = shift; }
    else    { return $self->{$name}; } 
}