text: #include <algorithm>
  #include <cassert>
  #include <chrono>
  #include <cstddef>
  #include <cstdint>
  #include <cstdlib>
  #include <iostream>
  #include <memory>
  #include <numeric>
  #include <thread>
  #include <vector>
  
  #include "buffered_channel.hpp"
  
  using channel_type = buffered_channel< std::uint64_t >;
  using clock_type = std::chrono::steady_clock;
  using duration_type = clock_type::duration;
  using time_point_type = clock_type::time_point;
  
  // microbenchmark
  void skynet( channel_type & c, std::size_t num, std::size_t size, std::size_t div) {
      if ( 1 == size) {
          c.push( num);
      } else {
          channel_type rc{ 16 };
          for ( std::size_t i = 0; i < div; ++i) {
              auto sub_num = num + i * size / div;
              std::thread{ skynet, std::ref( rc), sub_num, size / div, div }.detach();
          }
          std::uint64_t sum{ 0 };
          for ( std::size_t i = 0; i < div; ++i) {
              sum += rc.value_pop();
          }
          c.push( sum);
      }
  }
  
  int main() {
      try {
          std::size_t size{ 10000 };
          std::size_t div{ 10 };
          std::uint64_t result{ 0 };
          duration_type duration{ duration_type::zero() };
          channel_type rc{ 2 };
          time_point_type start{ clock_type::now() };
          skynet( rc, 0, size, div);
          result = rc.value_pop();
          duration = clock_type::now() - start;
          std::cout << "Result: " << result << " in " << duration.count() / 1000000 << " ms" << std::endl;
          std::cout << "done." << std::endl;
          return EXIT_SUCCESS;
      } catch ( std::exception const& e) {
          std::cerr << "exception: " << e.what() << std::endl;
      } catch (...) {
          std::cerr << "unhandled exception" << std::endl;
      }
  	return EXIT_FAILURE;
  }
  