#!/usr/bin/perl
 
use strict;
use warnings;

use Benchmark qw /cmpthese timethese/;
    
our $size = 100_000;
    
cmpthese timethese (-10 =>  {
    push      =>  'my @arr; push @arr => $_ for 0 .. $::size - 1',
    assign    =>  'my @arr; $arr [$_] =  $_ for 0 .. $::size - 1',
    assignpre =>  'my @arr; $#arr = $::size - 1;
                            $arr [$_] =  $_ for 0 .. $::size - 1', 
    slice     =>  'my @arr; @arr [0 .. $::size - 1] = (0 .. $::size - 1)',
    slicepre  =>  'my @arr; $#arr = $::size - 1;
                            @arr [0 .. $::size - 1] = (0 .. $::size - 1)',
} => 'none');
__END__
            Rate  slicepre     slice      push assignpre    assign
slicepre  3.82/s        --       -1%      -37%      -40%      -41%   
slice     3.87/s        1%        --      -36%      -39%      -40%
push      6.08/s       59%       57%        --       -4%       -5%  
assignpre 6.36/s       66%       64%        5%        --       -1%
assign    6.44/s       68%       66%        6%        1%        --