[ENH] Added a default virtual destructor to NormalizationStrategy class.

src/NormalizationStrategy/NormalizationStrategy.cpp

@@ -10,6 +10,8 @@
 BOOST_CLASS_EXPORT_IMPLEMENT(NormalizationStrategy)
 BOOST_CLASS_EXPORT_IMPLEMENT(DoubleUnitStrategy)
 
+//NormalizationStrategy::~NormalizationStrategy() = def
+
 double NormalizationStrategy::get_max_value() {
     return this->max_min_inp_val.at(0);
 }

src/NormalizationStrategy/NormalizationStrategy.h

@@ -23,6 +23,8 @@ public:
      */
     struct access;
 
+    virtual ~NormalizationStrategy () = default;
+
     /**
      *
      * @param n
@@ -72,7 +74,7 @@ public:
      */
     DoubleUnitStrategy();
 
-    ~DoubleUnitStrategy();
+    ~DoubleUnitStrategy() override;
 
     /**
      * Normalizes the input value to the interval [-1,1]