The code my $that={%$this} will do for copying one level of references. But if you want more than one level, it won't:

my $this={name=>'alex',array=>['one','two']};
my $that={%$this};
$that->{name}='Ido';
print $this->{name}; #alex - not affected
$that->{array}[0]='three';
print $this->{array}[0];#three - affected
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In order to copy more than one level of references, use Data::Dumper:

use Data::Dumper;
my $this={name=>'alex',array=>['one','two']};
my $that=eval Dumper $this;
$that->{name}='Ido';
print $this->{name}; #alex - not affected
$that->{array}[0]='three';
print $this->{array}[0];#one - not affected
[download]