Select Code to Download

use Test::More tests => 6;

...
is_deeply( [ 1 ], [ values %h ], 'values works' );
is( $h{undef()}, 1, 'undef key accesses value' );
is( $h{''},      1, 'empty string key accesses value' );

package UndefKey;
sub TIEHASH { bless [], __PACKAGE__ }
...
package main;
#my %h = ( undef() => 1 );
tie my %h, 'UndefKey';