#!/usr/local/bin/perl
use strict;
use warnings;
use Data::Dumper;

my %hash = ( 'a' => 2 );
use constant A => \%hash;
print A->{a};

##</code><code>##

#!/usr/local/bin/perl
use strict;
use warnings;
use Data::Dumper;

my $hash = { 'a' => 2 };

use constant A => $hash;
print A->{a};