#!/usr/bin/perl -w
use strict;
use Benchmark qw(cmpthese);

# Yes I do want it to be 5000 if $ARGV[0] is 0 ;)
my $n = $ARGV[0] || 5000;

# Grab a chunk of memory and give it to perl.
my @array = (1..50000);
undef @array;

cmpthese(-10, {
    a => "&a($n)",
    b => "&b($n)",
    c => "&c($n)",
    d => "&d($n)",
});

sub a {
    my @a = (1..shift);
    my $m;
    
    for ( @a ) {
        $m = $_;
    };
}

sub b {
    my @a = (1..shift);
    my $m;

    for my $i ( @a ){
        $m = $i
    };
}


sub c {
    my @a = (1..shift);
    my $m;

    $m = $_ for ( @a );
}


sub d {
    my @a = (1..shift);
    my $m;

    for (my $i=0; $i <= $#a; $i++) {
        $m = $a[$i];
    };
}