abstract_class2.vala added

cpp/figure/figure.cpp

@@ -0,0 +1,37 @@
+#include <iostream>
+
+using namespace std;
+
+class Figure {
+  public:
+	 void draw () {
+		cout << "Figure:draw () called" << endl;
+	}
+};
+
+class Circle : public Figure {
+  public:
+	 void draw () {
+		cout << "Circle:draw () called" << endl;
+	}
+};
+
+class ColorCircle : public Circle {
+  public:
+	 void draw () {
+		cout << "ColorCircle:draw () called" << endl;
+	}
+};
+
+int main () {
+
+	Figure *fig = new ColorCircle ();
+
+	fig->draw ();
+
+	Circle fig2 = *(Circle*)fig;
+
+	fig2.draw ();
+
+	return 0;
+}

vala/abstract_class2/abstract_class2.vala

@@ -0,0 +1,36 @@
+public interface Drawable : Object {
+
+	public abstract void draw ();
+}
+
+public abstract class Figure : Object, Drawable {
+	public virtual void draw () {
+		stdout.printf ("Figure:draw() called\n");
+	}
+}
+
+public class Circle : Figure {
+	public override void draw () {
+		stdout.printf ("Circle:draw() called\n");
+	}
+}
+
+public class ColorCircle : Circle {
+	public override void draw () {
+		stdout.printf ("ColorCircle:draw() called\n");
+	}
+}
+
+void main () {
+	var cc = new ColorCircle ();
+	cc.draw ();
+
+	Circle c = cc;
+	c.draw ();
+
+	Figure f = c;
+	f.draw ();
+
+	Drawable d = f;
+	d.draw ();
+}