use strict;
use warnings;
use Benchmark qw(cmpthese);

my @template = (1) x 200;

cmpthese
  (
  -10,
    {
    'push pop', sub {pushPop ();},
    'push shift', sub {pushShift ();},
    'unshift pop', sub {unshiftPop ();},
    'unshift shift', sub {unshiftShift ();},
    }
  );

sub pushPop
{
my @from = @template;
my @to;
for (0..100)
  {
  push @to, pop @from for @from;
  push @from, pop @to for @to;
  }
}

sub pushShift
{
my @from = @template;
my @to;
for (0..100)
  {
  push @to, shift @from for @from;
  push @from, shift @to for @to;
  }
}

sub unshiftPop
{
my @from = @template;
my @to;
for (0..100)
  {
  unshift @to, pop @from for @from;
  unshift @from, pop @to for @to;
  }
}

sub unshiftShift
{
my @from = @template;
my @to;
for (0..100)
  {
  unshift @to, shift @from for @from;
  unshift @from, shift @to for @to;
  }
}

##</code><code>##

               Rate unshift shift      push pop   unshift pop    push shift
unshift shift 129/s            --           -0%           -4%           -6%
push pop      129/s            0%            --           -3%           -6%
unshift pop   134/s            4%            3%            --           -2%
push shift    137/s            6%            6%            2%            --