use Data::Dumper;
use Devel::Size qw(total_size);

my $bigfoo = 'foo' x 1_000;
my @assigned = $bigfoo =~ /(foo)/g;
my @pushed;
push @pushed, $1 while $bigfoo =~ /(foo)/g;

printf "pushed:   %d\n", total_size( \@pushed );
printf "assigned: %d\n", total_size( \@assigned );

if ( Dumper( \@pushed ) eq Dumper( \@assigned ) ) {
    print "They look the same.\n";
}
else {
    print "They look different.\n";
}
__END__
pushed:   52132
assigned: 32052
They look the same.

##</code><code>##

pushed:   32132
assigned: 32052