#!/usr/bin/env perl

use strict;
use warnings;

use Benchmark qw{cmpthese};

my @keys = 'aa' .. 'zz';

cmpthese 1e5 => {
    a_inc => sub { my %hash; ++$hash{$_} for @keys },
    undef => sub { my %hash; $hash{$_} = undef for @keys },
    val_0 => sub { my %hash; $hash{$_} = 0 for @keys },
    val_1 => sub { my %hash; $hash{$_} = 1 for @keys },
    val42 => sub { my %hash; $hash{$_} = 42 for @keys },
};