Consider the following:

use strict;
use warnings;
my %hash = ( foo => 1, bar => 2, baz => 3 );
my $rhash1 = \%hash;
my $rhash2 = { %hash };
$rhash1->{ baz } = 5;
$rhash2->{ bar } = 7;
use Dumpvalue;
my $dumper = Dumpvalue->new();
print "\%hash:$/";
print $dumper->dumpValue( \%hash );
print "\$rhash1:$/";
print $dumper->dumpValue( $rhash1 );
print "\$rhash2:$/";
print $dumper->dumpValue( $rhash2 );
__END__
%hash:
'bar' => 2
'baz' => 5
'foo' => 1
$rhash1:
'bar' => 2
'baz' => 5
'foo' => 1
$rhash2:
'bar' => 7
'baz' => 3
'foo' => 1
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