}                                                                     \
    if (index < 0 || index >= list->response.size()) {                    \
      status->status = InvalidArgument("index out of bounds");            \
      return err_val;                                                     \
    }                                                                     \

  return result;
}

// Used as an argument to TFE_NewCustomDeviceTensorHandle, indicating how
// ParallelTensors wrapped in TFE_TensorHandles should be cleaned up once their
// reference counts drop to zero.
void ParallelTensorDeallocator(void* data) {
  delete reinterpret_cast<ParallelTensor*>(data);
}

// Used as an argument to TFE_NewCustomDeviceTensorHandle, for computing the