{ tie my $dst => 'Tie::DataDumper::More', 'scalar.dd', 0666; $src = { scalar => $scalar, array => [@array], hash=>{%hash} }; $dst = $src; }{ tie my $dst => 'Tie::DataDumper::More', 'scalar.dd', 0444; is_deeply($dst, $src, 'Tie::DataDumper::More'); eval{ $dst = '' }; ok($@, 'Tie::DataDumper::More - readonly'); }