Function ParallelForAsync

cpp/src/arrow/util/parallel.h:51–63

template <class FUNCTION, typename T,
          typename R = typename internal::call_traits::return_type<FUNCTION>::ValueType>
Future<std::vector<R>> ParallelForAsync(std::vector<T> inputs, FUNCTION&& func,
                                        Executor* executor = internal::GetCpuThreadPool(),
                                        TaskHints hints = TaskHints{}) {
  std::vector<Future<R>> futures(inputs.size());
  for (size_t i = 0; i < inputs.size(); ++i) {
    ARROW_ASSIGN_OR_RAISE(futures[i],
                          executor->Submit(hints, func, i, std::move(inputs[i])));
  }
  return All(std::move(futures))
      .Then([](const std::vector<Result<R>>& results) -> Result<std::vector<R>> {
        return UnwrapOrRaise(results);
      });
}

// A parallelizer that takes a `Status(int)` function and calls it with
// arguments between 0 and `num_tasks - 1`, in sequence or in parallel,