New example to test free_functions. Makes use of tracking objects functionality.

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@7522 626c5289-ae23-0410-ae9c-e8d60b6d4f22

SWIG/Examples/ruby/free_function/example.i

@@ -0,0 +1,41 @@
+%module example
+
+%{
+#include "example.h"
+%}
+
+/* Specify that ownership is transferred to the zoo
+	when calling add_animal */
+%apply SWIGTYPE *DISOWN { Animal* animal };
+
+/* Track objects */
+%trackobjects;
+
+/* Specify the mark function */
+%freefunc Zoo "free_Zoo";
+
+%include "example.h"
+
+%header %{
+	static void free_Zoo(void* ptr) {
+		Zoo* zoo = (Zoo*) ptr;
+
+		/* Loop over each object and call SWIG_RemoveMapping */
+		int count = zoo->get_num_animals();
+
+		for(int i = 0; i < count; ++i) {
+			/* Get an animal */
+			Animal* animal = zoo->get_animal(i);
+			/* Unlink the Ruby object from the C++ object */
+			SWIG_RubyUnlinkObjects(animal);
+			/* Now remove the tracking for this animal */
+			SWIG_RubyRemoveTracking(animal);
+		}
+
+	   /* Now call SWIG_RemoveMapping for the zoo */
+		SWIG_RubyRemoveTracking(ptr);
+
+		/* Now free the zoo which will free the animals it contains */
+		delete zoo;
+	}
+%}