use strict;
use Benchmark qw(cmpthese);

local $/ = undef;
open IN, "romeo-and-juliet-500-times.txt";
my $text = <IN>;
close IN;

# Ten iterations is enough with a 70 MB string!
cmpthese(10, {
  'i'       => sub { $text =~ /abc/ig },
  'chars'   => sub { $text =~ /[Aa][Bb][Cc]/g },
});