use warnings;
use strict;
use Devel::Size qw(total_size);

use warnings;
use strict;

my @large_list = (
    {key => 1, cond => 1},
    {key => 2, cond => 0},
    {key => 3, cond => 0},
    {key => 3, cond => 0},
    {key => 1, cond => 0},
    );

my $recordU = bless {};
my $recordA = bless {};
my $recordI = bless {};
my %record;

print "Empty sizes:\n";
print 'Packed: ', total_size ($recordU), "\n";
print 'Array:  ', total_size ($recordA), "\n";
print 'int:    ', total_size ($recordI), "\n";
print 'Hash:   ', total_size (\%record), "\n";

for my $item (@large_list) {
    $recordU->addU ($item);
    $recordA->addA ($item);
    $recordI->addI ($item);
    $record{$item->{key}}{count}++;
    $record{$item->{key}}{flag} ||= $item->{cond};
}

print "\nPopulated sizes:\n";
print 'Packed: ', total_size ($recordU), "\n";
print 'Array:  ', total_size ($recordA), "\n";
print 'int:    ', total_size ($recordI), "\n";
print 'Hash:   ', total_size (\%record), "\n";

for (sort keys %$recordU) {
    print "Item $_ count ", $recordU->getCountU ($_), ', flag ', $recordU->getFlagU ($_), "\n";
    print "Item $_ count ", $recordA->getCountA ($_), ', flag ', $recordA->getFlagA ($_), "\n";
    print "Item $_ count ", $recordI->getCountI ($_), ', flag ', $recordI->getFlagI ($_), "\n";
    print "Item $_ count ", $record{$_}{count}, ', flag ', $record{$_}{flag}, "\n";
}