serializatioin / deserialization and tests

include/NeuralNetwork/ActivationFunction/Sigmoid.h

@@ -29,11 +29,18 @@ namespace ActivationFunction {
 				return new Sigmoid(lambda);
 			}
 
-			virtual std::string stringify() const override {
-				return "{ \"class\": \"NeuralNetwork::ActivationFunction::Sigmoid\", \"lamba\" : "+std::to_string(lambda)+"}";
+			virtual SimpleJSON::Type::Object serialize() const override {
+				return {{"class", "NeuralNetwork::ActivationFunction::Sigmoid"}, {"lambda", lambda}};
 			}
+
+			static std::unique_ptr<Sigmoid> deserialize(const SimpleJSON::Type::Object &obj) {
+				return std::unique_ptr<Sigmoid>(new Sigmoid(obj["lambda"].as<double>()));
+			}
+
 		protected:
 			float lambda;
+
+		NEURAL_NETWORK_REGISTER_ACTIVATION_FUNCTION(NeuralNetwork::ActivationFunction::Sigmoid, Sigmoid::deserialize)
 	};
 }
 }