#### experimental::make_parallel_group (1 of 3 overloads)

Create a group of operations that may be launched in parallel.

    template<
        typename... Ops>
    parallel_group< Ops... > make_parallel_group(
        Ops... ops);

For example:

    asio::experimental::make_parallel_group(
      [&](auto token)
      {
        return in.async_read_some(asio::buffer(data), token);
      },
      [&](auto token)
      {
        return timer.async_wait(token);
      }
    ).async_wait(
      asio::experimental::wait_for_all(),
      [](
          std::array<std::size_t, 2> completion_order,
          std::error_code ec1, std::size_t n1,
          std::error_code ec2
      )
      {
        switch (completion_order[0])
        {
        case 0:
          {
            std::cout << "descriptor finished: " << ec1 << ", " << n1 << "\n";
          }
          break;
        case 1:
          {
            std::cout << "timer finished: " << ec2 << "\n";
          }
          break;
        }
      }
    );