Function async_wait_twice

example/cpp14/deferred/deferred_6.cpp:18–52

template <typename CompletionToken>
auto async_wait_twice(boost::asio::steady_timer& timer, CompletionToken&& token)
{
  return deferred.values(&timer)(
      deferred(
        [](boost::asio::steady_timer* timer)
        {
          timer->expires_after(std::chrono::seconds(1));
          return timer->async_wait(append(deferred, timer));
        }
      )
    )(
      deferred(
        [](boost::system::error_code ec, boost::asio::steady_timer* timer)
        {
          std::cout << "first timer wait finished: " << ec.message() << "\n";
          timer->expires_after(std::chrono::seconds(1));
          return deferred.when(!ec)
            .then(timer->async_wait(deferred))
            .otherwise(deferred.values(ec));
        }
      )
    )(
      deferred(
        [](boost::system::error_code ec)
        {
          std::cout << "second timer wait finished: " << ec.message() << "\n";
          return deferred.when(!ec)
            .then(deferred.values(42))
            .otherwise(deferred.values(0));
        }
      )
    )(
      std::forward<CompletionToken>(token)
    );
}

int main()
{