1 files changed, 51 insertions, 0 deletions
diff --git a/trunk/Examples/test-suite/csharp/virtual_poly_runme.cs b/trunk/Examples/test-suite/csharp/virtual_poly_runme.cs
new file mode 100644
index 000000000..9c1f79613
--- /dev/null
+++ b/trunk/Examples/test-suite/csharp/virtual_poly_runme.cs
@@ -0,0 +1,51 @@
+using System;
+using virtual_polyNamespace;
+
+public class runme {
+    static void Main() {
+
+        NDouble d = new NDouble(3.5);
+        NInt i = new NInt(2);
+
+        //
+        // These two natural 'copy' forms fail because no covariant (polymorphic) return types 
+        // are supported in C#. 
+        //
+        // NDouble dc = d.copy();
+        // NInt ic = i.copy();
+
+        //
+        // Unlike C++, we have to downcast instead.
+        //
+        NDouble dc = (NDouble)d.copy();
+        NInt ic = (NInt)i.copy();
+
+        NDouble ddc = NDouble.narrow(dc);
+        NInt dic = NInt.narrow(ic);
+        dc = ddc; ic = dic; // warning suppression
+
+        virtual_poly.incr(ic);
+        if ( (i.get() + 1) != ic.get() )
+            throw new Exception("incr test failed");
+
+        //
+        // Checking a pure user downcast
+        //
+        NNumber n1 = d.copy();
+        NNumber n2 = d.nnumber();
+        NDouble dn1 = NDouble.narrow(n1);
+        NDouble dn2 = NDouble.narrow(n2);
+
+        if ( (dn1.get()) != dn2.get() )
+          throw new Exception("copy/narrow test failed");
+
+        //
+        // Checking the ref polymorphic case
+        //
+        NNumber nr = d.ref_this();
+        NDouble dr1 = NDouble.narrow(nr);
+        NDouble dr2 = (NDouble)d.ref_this();
+        if ( dr1.get() != dr2.get() )
+          throw new Exception("copy/narrow test failed");
+  }
+}