use Benchmark 'cmpthese';

@list = 1 .. 1_000_000;
@result = @list;
$result = \ @list;
cmpthese( 0, {
    list => sub { @result = sub {   @list }->() },
    refr => sub { $result = sub { \ @list }->() } } );
#          Rate      list      refr
# list   1.67/s        --     -100%
# refr 774198/s 46258208%        --