style: separate base class members

Author: voltjia

src/base/nll_loss2d_backward_grad_input.h

@@ -35,20 +35,35 @@ class NllLoss2dBackwardGradInput : public Operator<NllLoss2dBackwardGradInput> {
 
  protected:
   Tensor::Shape grad_output_shape_;
+
   Tensor::Strides grad_output_strides_;
+
   DataType grad_output_type_;
+
   Tensor::Shape self_shape_;
+
   Tensor::Strides self_strides_;
+
   DataType self_type_;
+
   Tensor::Shape target_shape_;
+
   Tensor::Strides target_strides_;
+
   DataType target_type_;
+
   Tensor::Shape total_weight_shape_;
+
   Tensor::Strides total_weight_strides_;
+
   DataType total_weight_type_;
+
   Tensor::Shape grad_input_shape_;
+
   Tensor::Strides grad_input_strides_;
+
   DataType grad_input_type_;
+
   int device_index_{0};
 };