added test for simple virtual derivation, where ruby fails

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@5666 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/test-suite/python/virtual_derivation_runme.py

@@ -0,0 +1,8 @@
+from virtual_derivation import *
+#
+# very innocent example
+#
+b = B(3)
+if b.get_a() != b.get_b():
+  raise RuntimeError, "something is really wrong"
+

Examples/test-suite/ruby/virtual_derivation_runme.rb

@@ -0,0 +1,8 @@
+require 'virtual_derivation'
+
+b = Virtual_derivation::B.new 3
+
+if b.get_a() != b.get_b() 
+  print "something is really wrong ", b.get_a(), "\n"
+  raise RuntimeError 
+end

Examples/test-suite/virtual_derivation.i

@@ -0,0 +1,54 @@
+%module virtual_derivation
+
+ /*
+
+ Try to add to your favorite language a runtime test like
+ this:
+ 
+ b = B(3)
+ if (b.get_a() != b.get_b()):
+     print "something is wrong"
+
+
+ The test runs fine with python, but not with ruby.
+ 
+ */
+
+%inline %{
+
+  struct A 
+  {
+    ~A()
+    {
+    }
+    
+    int _a;
+    
+    A(int a) :_a(a)
+    {
+    }
+    
+    int get_a()
+    {
+      return _a;
+    }
+    
+  };
+  
+  struct B : virtual A
+  {
+    B(int a): A(a)
+    {
+    }
+    
+    int get_b()
+    {
+      return get_a();
+    }
+
+    // in ruby, get_a() returns trash if called from b, unless is
+    // wrapped with the previous get_b or using the 'using'
+    // declaration:
+    // using A::get_a;
+  };
+%}