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

use Benchmark qw{ cmpthese };

sub outer {
    my $s = 0;
    my $x;
    for $x (1 .. 5) {
        $s += $x;
    }
    $s
}

sub inner {
    my $s = 0;
    for my $x (1 .. 5) {
        $s += $x;
    }
    $s
}

outer() == inner() or die 'Error in implementation';

cmpthese(-2, {
    outer => 'outer()',
    inner => 'inner()',
});