1 files changed, 25 insertions, 0 deletions
diff --git a/doc/sources/c++/polygon.h b/doc/sources/c++/polygon.h
new file mode 100644
index 0000000..e3189bf
--- /dev/null
+++ b/doc/sources/c++/polygon.h
@@ -0,0 +1,25 @@
+#ifndef POLYGON_HPP
+#define POLYGON_HPP
+
+class polygon
+{
+	protected:
+		double side_length_;
+
+	public:
+		polygon() : side_length_(0)
+		{}
+
+		void set_side_length(double side_length)
+		{
+			side_length_ = side_length;
+		}
+
+		virtual double area() const = 0;
+};
+
+// the types of the class factories
+typedef polygon* create_t();
+typedef void destroy_t(polygon*);
+
+#endif