Ensure that non-shared_ptr, non-boxed_value, non-reference return types

are treated as const.

include/chaiscript/chaiscript_threading.hpp

@@ -23,6 +23,7 @@
 
 namespace chaiscript
 {
+  /// \internal
   namespace detail
   {
     namespace threading

include/chaiscript/dispatchkit/handle_return.hpp

@@ -27,7 +27,7 @@ namespace chaiscript
       {
         static Boxed_Value handle(const Ret &r)
         {
-          return Boxed_Value(r);
+          return const_var(r);
         }
       };
 
@@ -40,6 +40,15 @@ namespace chaiscript
         }
       };
 
+    template<typename Ret>
+      struct Handle_Return<boost::shared_ptr<Ret> >
+      {
+        static Boxed_Value handle(const boost::shared_ptr<Ret> &r)
+        {
+          return Boxed_Value(r);
+        }
+      };
+
     template<typename Ret>
       struct Handle_Return<const boost::shared_ptr<Ret> &>
       {
@@ -88,6 +97,18 @@ namespace chaiscript
         }
       };
 
+    /**
+     * Used internally for handling a return value from a Proxy_Function call
+     */
+    template<>
+      struct Handle_Return<const Boxed_Value>
+      {
+        static Boxed_Value handle(const Boxed_Value &r)
+        {
+          return r;
+        }
+      };
+
     /**
      * Used internally for handling a return value from a Proxy_Function call
      */

unittests/assign_const.chai

@@ -0,0 +1,2 @@
+assert_throws("Mismatched types in equation, lhs is const.", fun() { 1 = 2 } );
+assert_throws("Mismatched types in equation, lhs is const.", fun() { 1 + 2 = 2 } );