#! /usr/bin/perl -w

<code>
use strict;
use vars qw/ $r $r2 /;

$r = {
  foo => [
    { one  => 1, two  => 2, three => 3 },
    { four => 4, five => 5, six   => 6 },
  ],
};

{
    print "orig : $r->{foo}[1]{five}\n";
    $r2 = $r->{foo};
    local $r2->[1]{five} = $r2->[1]{five} + 500;
    print "then : $r->{foo}[1]{five}\n\n";
}

print "after: $r->{foo}[1]{five}\n";