Function wait_on_futures

python/cpp/utils.h:100–106

    template <typename Result>
    std::vector<Result> wait_on_futures(std::vector<std::future<Result>> futures) {
      std::vector<Result> results;
      results.reserve(futures.size());
      for (auto& future : futures)
        results.emplace_back(future.get());
      return results;
    }

    template <typename Result>
    std::variant<std::vector<Result>, std::vector<AsyncResult<Result>>>