Method CheckValid

cpp/src/arrow/util/future.h:664–670

  }

  void CheckValid() const {
#ifndef NDEBUG
    if (!is_valid()) {
      Status::Invalid("Invalid Future (default-initialized?)").Abort();
    }
#endif
  }

  explicit Future(std::shared_ptr<FutureImpl> impl) : impl_(std::move(impl)) {}