text: #ifndef CAFFE2_OPERATORS_TOP_K_H_
  #define CAFFE2_OPERATORS_TOP_K_H_
  
  #include "caffe2/core/logging.h"
  #include "caffe2/core/operator.h"
  #include "caffe2/utils/math.h"
  
  namespace caffe2 {
  
  template <typename T, class Context>
  class TopKOp : public Operator<Context> {
   public:
    USE_OPERATOR_CONTEXT_FUNCTIONS;
  
    template <class... Args>
    explicit TopKOp(Args&&... args)
        : Operator<Context>(std::forward<Args>(args)...),
          OP_SINGLE_ARG(int, "k", k_, -1),
          OP_SINGLE_ARG(int, "axis", axis_, -1) {
      CAFFE_ENFORCE(k_ >= 1, "k argument must be >= 1");
    }
  
    ~TopKOp() {}
  
    bool RunOnDevice() override;
  
   private:
    const int k_;
    int axis_;
  };
  
  template <typename T, class Context>
  class TopKGradientOp : public Operator<Context> {
   public:
    USE_OPERATOR_CONTEXT_FUNCTIONS;
  
    template <class... Args>
    explicit TopKGradientOp(Args&&... args)
        : Operator<Context>(std::forward<Args>(args)...),
          OP_SINGLE_ARG(int, "axis", axis_, -1) {}
  
    ~TopKGradientOp() {}
  
    bool RunOnDevice() override;
  
   private:
    int axis_;
  };
  
  } // namespace caffe2
  
  #endif // CAFFE2_OPERATORS_TOP_K_H_
  