added the ruby runtime case and more comments.

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@5584 626c5289-ae23-0410-ae9c-e8d60b6d4f22

SWIG/Examples/test-suite/python/virtual_poly_runme.py

@@ -1,9 +1,11 @@
 import virtual_poly
 
-
 d = virtual_poly.NDouble(3.5)
 i = virtual_poly.NInt(2)
 
+#
+# the copy methods return the right polymorphic types
+# 
 dc = d.copy()
 ic = i.copy()
 
@@ -14,6 +16,14 @@ if i.get() != ic.get():
   raise RuntimeError
 
 
-ddc = virtual_poly.NDouble_dynamic_cast(dc)
+#
+# here this dynamic_cast is not needed at all,
+# but works fine anyway ('nnumber()' returns a NNumber).
+#
+ddc = virtual_poly.NDouble_dynamic_cast(dc.nnumber())
 if d.get() != ddc.get():
   raise RuntimeError
+
+dic = virtual_poly.NInt_dynamic_cast(ic.nnumber())
+if i.get() != dic.get():
+  raise RuntimeError