pack is a bit faster than join: 
use strict;
use warnings;
use Benchmark qw(:all) ;

my @foo = qw/1 2 3 4 5 6/;
my %bar = (pack('b', @foo) => 'elephants');

my @baz = qw/1 2 3 4 5 6/;

print $bar{pack('b', @baz)} . "\n";

cmpthese(-5, {
    'join' => sub { join('', qw/1 2 3 4 5 6/) },
    'pack' => sub { pack('b', qw/1 2 3 4 5 6/) },
});

[download]
prints: 
% perl test.pl
elephants
          Rate join pack
join 1002841/s   -- -53%
pack 2119814/s 111%   --
%

[download]

In reply to Re: non-scalar hash key by Arunbear
in thread non-scalar hash key by kdejonghe

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