use strict;
use warnings;
use Benchmark qw(cmpthese);

my $string = '0'x13;
cmpthese(0, {
    'eq_loop' => q(for (0..12) {
         next if ($string eq '0000000000000');
         $_ = ($string =~ tr/1/1/);
     }),
    'tr_loop' => q(for (0..12) {
         next unless ($_ = ($string =~ tr/1/1/));
    }),
    'eq' => q($string eq '0000000000000';),
    'tr' => q($string =~ tr/1/1/;),
});