add a C++ extention example to the available code base

docs/examples/tutorial/rectangle_cpp/Rectangle.cpp

+#include <iostream>
+#include "Rectangle.h"
+
+namespace shapes {
+
+	// Default constructor
+	Rectangle::Rectangle () {}
+
+	// Overloaded constructor
+	Rectangle::Rectangle (int x0, int y0, int x1, int y1) {
+		this->x0 = x0;
+		this->y0 = y0;
+		this->x1 = x1;
+		this->y1 = y1;
+	}
+
+	// Destructor
+	Rectangle::~Rectangle () {}
+
+	// Return the area of the rectangle
+	int Rectangle::getArea () {
+		return (this->x1 - this->x0) * (this->y1 - this->y0);
+	}
+
+	// Get the size of the rectangle.
+	// Put the size in the pointer args
+	void Rectangle::getSize (int *width, int *height) {
+		(*width) = x1 - x0;
+		(*height) = y1 - y0;
+	}
+
+	// Move the rectangle by dx dy
+	void Rectangle::move (int dx, int dy) {
+		this->x0 += dx;
+		this->y0 += dy;
+		this->x1 += dx;
+		this->y1 += dy;
+	}
+}
+

docs/examples/tutorial/rectangle_cpp/Rectangle.h

+#ifndef RECTANGLE_H
+#define RECTANGLE_H
+
+namespace shapes {
+	class Rectangle {
+		public:
+			int x0, y0, x1, y1;
+			Rectangle();
+			Rectangle(int x0, int y0, int x1, int y1);
+			~Rectangle();
+			int getArea();
+			void getSize(int* width, int* height);
+			void move(int dx, int dy);
+	};
+}
+
+#endif // RECTANGLE_H

docs/examples/tutorial/rectangle_cpp/rect.pyx

+# disutils: language = c++
+# disutils: sources = Rectangle.cpp
+
+# Decalre the class with cdef
+cdef extern from "Rectangle.h" namespace "shapes":
+    cdef cppclass Rectangle:
+        Rectangle() except +
+        Rectangle(int, int, int, int) except +
+        int x0, y0, x1, y1
+        int getArea()
+        void getSize(int* width, int* height)
+        void move(int, int)
+
+# Create a Cython extension type which holds a C++ instance
+#    as an attribute and create a bunch of forwarding methods
+# Python extension type:
+cdef class PyRectangle:
+
+    cdef Rectangle c_rect  # Hold a C++ instance which we're wrapping
+    
+    def __cinit__(self, int x0, int y0, int x1, int y1):
+        self.c_rect = Rectangle(x0, y0, x1, y1)
+
+    def get_area(self):
+        return self.c_rect.getArea()
+    
+    def get_size(self):
+        cdef int width, height
+        self.c_rect.getSize(&width, &height)
+        return width, height
+
+    def move(self, dx, dy):
+        self.c_rect.move(dx, dy)
+
+    # Attribute access
+    @property
+    def x0(self):
+        return self.c_rect.x0
+
+    @x0.setter
+    def x0(self, x0):
+        self.c_rect.x0 = x0
+
+
+def main():
+    rec_ptr = new Rectangle(1, 2, 3, 4)  # Instantiate a Rectangle object on the heap
+    try:
+        recArea = rec_ptr.getArea()
+    finally:
+        del rec_ptr  # delete heap allocated object
+
+    cdef Rectangle rec_stack  # Instantiate a Rectangle object on the stack
+
+
+if __name__ == "__main__":
+    main()

docs/examples/tutorial/rectangle_cpp/setup.py

+from distutils.core import setup, Extension
+from Cython.Build import cythonize
+
+setup(ext_modules = cythonize(Extension(
+           "rect",                                # the extension name
+           sources=["rect.pyx", "Rectangle.cpp"], # the Cython source and
+                                                  # additional C++ source files
+           language="c++",                        # generate and compile C++ code
+      )))

docs/examples/tutorial/rectangle_cpp/test_import.py

+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+try:
+    import rect
+except ImportError:
+    print("Module rect has not yet been built")
+    print("Please run $python setup.py build_ext --inplace")
+    print("Then try again")
+
+x0, y0, x1, y1 = 1, 2, 3, 4
+
+rect_obj = rect.PyRectangle(x0, y0, x1, y1)
+print(dir(rect_obj))
+