Hash keys are stringified, and thus, references can't be hash keys. If you place a reference in a hash key it gets stringified to something like "ARRAY 0x3E0CFF", and can't be resurrected.

Are you looking for a hash slice?

my %hash;
@hash{ 'A', 'B', 'C' } = ( 1, 2, 3 );

[download]

Incidentally (and a bit off your original topic), the fact that references stringify when used as hash keys -- including blessed refs -- is the basis for keeping track of inside-out objects: 

package InOut;

use strict;
use warnings;


my %instances;

sub new {
    my( $class, @params ) = @_;
    my $obj = bless {}, $class;
    $instances{$obj} = { params => [ @params ]};
    return $obj;
}

sub getparam {
    my ( $self, $index ) = @_;
    return $instances{$self}{params}[$index];
}

1;

package main;

use strict;
use warnings;

my $thingy = InOut->new(qw/ Bart Homer Marge Maggie Lisa / );

print $thingy->getparam( 2 ), "\n";

[download]

Dave

In reply to Re: HoHoA with anonymous array refs as the key to access the A by davido
in thread HoHoA with anonymous array refs as the key to access the A by Grygonos

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