unit test for resolving abstract types inside a namespace (#2554)

diff --git a/Examples/test-suite/cpp11_using_typedef_struct.i b/Examples/test-suite/cpp11_using_typedef_struct.i
index 4c7724f..856070f 100644
--- a/Examples/test-suite/cpp11_using_typedef_struct.i
+++ b/Examples/test-suite/cpp11_using_typedef_struct.i
@@ -11,11 +11,19 @@
     int x;
   };
   typedef struct xCacheView CacheView;
+
+  struct _xAbstract;
+  typedef struct _xAbstract Abstract;
 }
 
 using nspace1::AffineMatrix;
 using nspace1::CacheView;
+using nspace1::Abstract;
+
+void _internal(const Abstract *) {}
 
 int fn1(AffineMatrix a) { return a.x; };
 int fn2(CacheView a) { return a.x; };
+int fn3(Abstract *a) { _internal(a); return 0; };
+int fn4(const Abstract *a) { _internal(a); return 0; };
 %}