perl -MMemoize -MMemoize::Expire -E " \
    sub f { ('X',int rand 100) }; \ 
    tie my %cache => 'Memoize::Expire', NUM_USES => 3; \
    memoize 'f', LIST_CACHE => 'MERGE', \
                 SCALAR_CACHE => [ HASH => \%cache ]; \
    for (1..6) { say f() }"

##</code><code>##

perl -MMemoize -MMemoize::Expire -MSerializeValues -E " \
     sub f { ('X',int rand 100) }; \
     tie my %subcache => 'Memoize::Expire', NUM_USES => 3; \
     tie my %cache => 'SerializeValues', \%subcache; \
     memoize 'f', LIST_CACHE => [ HASH => \%cache ], \
                  SCALAR_CACHE =>'MERGE' ; \
     for (1..6) { say f() }"

##</code><code>##

#!/usr/bin/env perl

package SerializeValues;
require Tie::Hash;
 @ISA = qw(Tie::ExtraHash);

use strict;
use warnings;
use Storable qw[freeze thaw];


sub TIEHASH {
  my ($class, $child_hash) = @_;
  return bless [$child_hash], $class;
}

sub STORE {
  $_[0][0]{$_[1]}= freeze $_[2]
}

sub FETCH {
  thaw $_[0][0]{$_[1]}
}