#!/usr/bin/perl
use strict;
use warnings;
use version;
use Benchmark qw(cmpthese);

my $str = "bea" x 100;
my $re = qr/(?:be|ea|a)/;
cmpthese(-2, {
    atomic1   => sub { die if $str =~ m/(?>$re+)\d/ },
    atomic2   => sub { die if $str =~ m/(?>$re)+\d/ },
    normal    => sub { die if $str =~ m/$re+\d/ },
    ( version->new($]) >= version->new("5.10.0")
      ? (posessive => sub { die if $str =~ m/$re++\d/ })
      : ()
    ),
});
__END__
5.8.8:

          Rate  normal atomic2 atomic1
normal  5000/s      --     -4%    -18%
atomic2 5208/s      4%      --    -15%
atomic1 6132/s     23%     18%      --

5.11:
            Rate posessive   atomic1   atomic2    normal
posessive 59.9/s        --       -1%      -97%      -97%
atomic1   60.4/s        1%        --      -97%      -97%
atomic2   1953/s     3159%     3134%        --       -9%
normal    2156/s     3500%     3472%       10%        --