Results of the run

results.pl

$VAR1 = {
          'readonly' => sub {
                            use warnings;
                            use strict 'refs';
                            my $i = 0;
                            if (defined $test_hash{$READONLY_KEY}) {
                                if ($test_hash{$READONLY_KEY} eq $READONLY_VALUE) {
                                    $i++;
                                }
                            }
                        },
          'use_constant' => sub {
                                use warnings;
                                use strict 'refs';
                                my $i = 0;
                                if (defined $test_hash{'key'}) {
                                    if ($test_hash{'key'} eq 'value') {
                                        $i++;
                                    }
                                }
                            },
          'const_fast' => sub {
                              use warnings;
                              use strict 'refs';
                              my $i = 0;
                              if (defined $test_hash{$CONST_FAST_KEY}) {
                                  if ($test_hash{$CONST_FAST_KEY} eq $CONST_FAST_VALUE) {
                                      $i++;
                                  }
                              }
                          }
        };

use_constant: Ran 1214 iterations (189 outliers).
use_constant: Rounded run time per iteration: 4.6662e-07 +/- 1.2e-10 (0.0%)
readonly: Ran 1214 iterations (186 outliers).
readonly: Rounded run time per iteration: 4.7046e-06 +/- 2.1e-09 (0.0%)
const_fast: Ran 1546 iterations (528 outliers).
const_fast: Rounded run time per iteration: 4.6802e-07 +/- 1.2e-10 (0.0%)