Adapt Yield Curve and Volatility Surface and Market Data, to be better compatible with unit test.

src/StochasticProcess.hpp

@@ -9,20 +9,20 @@
 
 class StochasticProcess {
 public:
-    StochasticProcess() = default;
-    StochasticProcess(std::unique_ptr<MarketData> data) : data_(std::move(data)){}
+    StochasticProcess() = delete;
+    explicit StochasticProcess(MarketData data) : data_(std::move(data)){}
 
     virtual ~StochasticProcess() = default;
     virtual double drift(double t, double s) = 0;
     virtual double diffusion(double t, double s) = 0;
     virtual double step(double t, double s, double dt, double dW) = 0;
-    MarketData& data() const {return *data_;}
+    const MarketData& data() const {return data_;}
 
 
 private:
-    std::shared_ptr<MarketData> data_;
+    MarketData data_;
 
 };
 
 
-#endif //QUANTENGINE_STOCHASTICPROCESS_HPP
+#endif //QUANTENGINE_STOCHASTICPROCESS_HPP