diff --git a/Circleoutline.h b/Circleoutline.h
index 1ba3f219..a0a6aed0 100644
--- a/Circleoutline.h
+++ b/Circleoutline.h
@@ -26,7 +26,7 @@
 #include <opencv2/opencv.hpp>
 #include <QJsonObject>
 void fillCircle(cv::Mat &m, double cx, double cy, double rad, void *color);
-class CircleOutline: public boundary
+class CircleOutline final: public boundary
 {
     public:
         CircleOutline();
@@ -35,7 +35,7 @@ class CircleOutline: public boundary
         CircleOutline(const QJsonObject &obj);
         void toJson(QJsonObject &obj);
 
-        virtual ~CircleOutline();
+        ~CircleOutline();
         void draw(QPainter& painter, double scale, double scale2 = -1.);
         bool isInside(QPointF& p , int offset = 0);
         bool isInside(double x, double y, int offset=0);
@@ -48,17 +48,15 @@ class CircleOutline: public boundary
         double m_radius;
         gPlus m_p1;
         gPlus m_p2;
-    protected:
-
-    private:
 };
 
-class ellipseOutline: public boundary
+class ellipseOutline final: public boundary
 {
 public:
     ellipseOutline();
     ellipseOutline(QPointF center, double minorAxis, double majorAxis);
     ellipseOutline(QPointF left, QPointF right, double ecc);
+    void draw(QPainter& painter, double scale, double scale2 = -1.);
     bool isInside(QPointF& p , int offset = 0);
     void enlarge(int del);
     void translate(QPointF del);
@@ -76,11 +74,12 @@ class ellipseOutline: public boundary
     gPlus m_p2;
 };
 
-class rectangleOutline: public boundary
+class rectangleOutline final: public boundary
 {
 public:
     rectangleOutline();
     rectangleOutline(QPointF upperLeft, QPointF lowerRight);
+    void draw(QPainter& painter, double scale, double scale2 = -1.);
     bool isInside(QPointF& p , int offset = 0);
     void enlarge(int del);
     void translate(QPointF del);
diff --git a/boundary.h b/boundary.h
index 2a897147..aed9b276 100644
--- a/boundary.h
+++ b/boundary.h
@@ -18,17 +18,26 @@
 #ifndef BOUNDARY_H
 #define BOUNDARY_H
 #include <QPainter>
+
+// asbtract base class. Zero risk of slicing.
 class boundary
 {
+    protected:
+        boundary() = default;
+        ~boundary() = default;
+        // Copy operations
+        boundary(const boundary&) = default;
+        boundary& operator=(const boundary&) = default;
+        // Move operations
+        boundary(boundary&&) noexcept = default;
+        boundary& operator=(boundary&&) noexcept = default;
     public:
-        virtual ~boundary() {}
         virtual void draw(QPainter& painter, double scale, double scale2 = -1.) = 0;
         virtual void enlarge(int del) = 0;
         virtual void translate(QPointF del) = 0;
         virtual void scale(double factor) = 0;
         virtual bool isValid() = 0;
         virtual bool isInside(QPointF& p, int offset = 0) = 0;
-    protected:
     private:
 };
 QDataStream & operator<<(QDataStream & stream, const boundary &outline);
diff --git a/gplus.h b/gplus.h
index 25210d7a..296f0db0 100644
--- a/gplus.h
+++ b/gplus.h
@@ -24,7 +24,7 @@ class gPlus
     public:
         gPlus(QPointF p);
         gPlus();
-        virtual ~gPlus();
+        ~gPlus();
         void draw(QPainter& dc, double scale, int size = 10);
         QPointF m_p;
     protected: