use strict;
  use warnings;

  use Hash::Ordered;
  use MCE::Shared::Ordhash;
  use List::Util 'shuffle';
  use Time::HiRes 'time';

  my ($start, $total); srand 0;

  sub ready {
      my $time = time;
      $total  += $time - $start;
      $start   = $time;
  }

# my $oh = Hash::Ordered->new();
  my $oh = MCE::Shared::Ordhash->new();

  print ref($oh), "\n";

  my @keys1 = shuffle('aaaa'..'gggf');  # size: 109,674
  my @keys2 = shuffle('gggg'..'mmmm');  # size: 109,675
  my @keys3 = shuffle('nnnn'..'ttts');  # size: 109,674
  my @keys4 = shuffle('tttt'..'zzzz');  # size: 109,675

  $oh->set($_,$_) for ('a'..'m','_','n'..'z'); # add 26 or more keys
  $oh->delete('_');                            # has INDX afterwards

  $start = time;
  $oh->set($_,$_) for @keys1;
  printf "duration (set    ): %0.02f\n", time - $start;

  ready();
  $oh->push($_,$_) for @keys2;
  printf "duration (push   ): %0.02f\n", time - $start;

  ready();
  $oh->unshift($_,$_) for @keys3;
  printf "duration (unshift): %0.02f\n", time - $start;

  ready();
  $oh->merge(map {$_,$_} @keys4);
  printf "duration (merge  ): %0.02f\n", time - $start;

# ready();
# $oh->delete($_) for @keys2;
# printf "duration (delete ): %0.02f\n", time - $start;

  printf "total time        : %0.02f\n", $total += time - $start;