Also add const to makeEvaluator

paddle/gserver/gradientmachines/GradientMachine.h

@@ -181,7 +181,7 @@ public:
   /**
    * Create an evaluator which can be used for eval()
    */
-  virtual Evaluator* makeEvaluator() = 0;
+  virtual Evaluator* makeEvaluator() const = 0;
 
   /**
    * evaluate using the given evaluator

paddle/gserver/gradientmachines/MultiGradientMachine.cpp

@@ -327,7 +327,7 @@ void MultiGradientMachine::finish() {
   }
 }
 
-Evaluator* MultiGradientMachine::makeEvaluator() {
+Evaluator* MultiGradientMachine::makeEvaluator() const {
   return threads_[0]->getGradientMachine()->makeEvaluator();
 }
 

paddle/gserver/gradientmachines/MultiGradientMachine.h

@@ -193,7 +193,7 @@ public:
 
   virtual void finish();
 
-  virtual Evaluator* makeEvaluator();
+  virtual Evaluator* makeEvaluator() const;
 
   virtual void eval(Evaluator* evaluator) const;
 

paddle/gserver/gradientmachines/MultiNetwork.cpp

@@ -172,7 +172,7 @@ protected:
   std::vector<std::unique_ptr<Evaluator>> evaluators_;
 };
 
-Evaluator* MultiNetwork::makeEvaluator() {
+Evaluator* MultiNetwork::makeEvaluator() const {
   MultiCombinedEvaluator* multiCombinedEvaluator = new MultiCombinedEvaluator();
   for (size_t i = 0; i < subNetworks_.size(); i++) {
     std::unique_ptr<Evaluator> evaluator(subNetworks_[i]->makeEvaluator());

paddle/gserver/gradientmachines/MultiNetwork.h

@@ -46,7 +46,7 @@ public:
 
   virtual void onPassEnd();
 
-  virtual Evaluator* makeEvaluator();
+  virtual Evaluator* makeEvaluator() const;
 
   virtual void eval(Evaluator* evaluator) const;
 

paddle/gserver/gradientmachines/NeuralNetwork.cpp

@@ -348,7 +348,7 @@ protected:
   std::vector<std::unique_ptr<Evaluator>> evaluators_;
 };
 
-Evaluator* NeuralNetwork::makeEvaluator() {
+Evaluator* NeuralNetwork::makeEvaluator() const {
   CombinedEvaluator* combinedEvaluator = new CombinedEvaluator();
   auto subModelConfig = std::find_if(config_.sub_models().begin(),
                                      config_.sub_models().end(),

paddle/gserver/gradientmachines/NeuralNetwork.h

@@ -96,7 +96,7 @@ public:
 
   virtual void onPassEnd();
 
-  virtual Evaluator* makeEvaluator();
+  virtual Evaluator* makeEvaluator() const;
 
   virtual void eval(Evaluator* evaluator) const;
   virtual void resetState();