#!/usr/bin/perl

use strict;
use warnings;
use Benchmark qw/:all :hireswallclock/;

my $test_str='error';
my @test=map {
    my @chr=("\0", " ");
    local $_=$test_str;
    s/./$& ^ $chr[rand 2]/ge} 1..100;

no warnings 'void';
cmpthese -30, { regex => sub { /^\Q$test_str\E$/i for @test },
                lc => sub { $test_str eq lc for @test} }, 'all';

__END__