use Benchmark qw(cmpthese);
cmpthese( -2,{
 list => sub { my ($self,%param) = @_ },
 shiftit => sub { my $self = shift; my %param = @_ },
} );
__END__
5.8.3       Rate    list shiftit
list     78392/s      --    -73%
shiftit 292680/s    273%      --
5.6.2       Rate    list shiftit
list     94936/s      --    -68%
shiftit 297717/s    214%      --