cmpthese( -2,{
 list => sub { list( qw(foo) ) },
 shiftit => sub { shiftit( qw(foo) ) },
} );
__END__
5.8.3       Rate shiftit    list
shiftit 164545/s      --    -19%
list    204158/s     24%      --
5.6.2       Rate shiftit    list
shiftit 179408/s      --    -12%
list    203990/s     14%      --