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

use Benchmark qw{cmpthese};

cmpthese( -1 => {
    no_assignment => sub {
        for( 1..10_000 ) {
            my %hash;
            $hash{$_} = $_;
            $hash{-$_} = -$_;
        }
    },
    assignment    => sub {
        for( 1..10_000 ) {
            my %hash = ();
            $hash{$_} = $_;
            $hash{-$_} = -$_;
        }
    },
} );
__END__
                 Rate     assignment ano_assignment
assignment     99.4/s             --            -8%
no_assignment   108/s             9%             --

##</code><code>##

                Rate no_assignment    assignment
no_assignment 96.6/s            --           -3%
assignment    99.4/s            3%            --

##</code><code>##

                Rate    assignment no_assignment
assignment    1068/s            --          -37%
no_assignment 1685/s           58%            --

##</code><code>##

                    Rate    assignment no_assignment
assignment    11967704/s            --          -49%
no_assignment 23642004/s           98%            --