package CD::Music;
use strict;
use vars '$AUTOLOAD';  # Keep 'use strict' happy

{
  my %_attrs =
    ( _name       => undef,
      _artist     => undef,
      _publisher  => undef,
      _ISBN       => undef,
      _tracks     => undef,
      _rating     => undef,
      _room       => undef,
      _shelf      => undef,
    );
  
  sub _accessible { exists $_attrs{$_[1]} }
}

sub AUTOLOAD
{

  my ($self) = @_;
  $AUTOLOAD =~ /.*::get(_\w+)/
    or croak "No such method: $AUTOLOAD";
  $self->_accessible($1) 
    or croak "No such attribute: $1";
  $self->{_read_count}++;
  return $self->($1);
}