From 87c29ebc91dc82ab6354549f0a953820b513f111 Mon Sep 17 00:00:00 2001
From: Jason Turner <lefticus@gmail.com>
Date: Sat, 26 Mar 2011 09:03:36 -0600
Subject: [PATCH] Ensure that non-shared_ptr, non-boxed_value, non-reference
 return types are treated as const.

---
 include/chaiscript/chaiscript_threading.hpp   |  1 +
 .../chaiscript/dispatchkit/handle_return.hpp  | 23 ++++++++++++++++++-
 unittests/assign_const.chai                   |  2 ++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 unittests/assign_const.chai

diff --git a/include/chaiscript/chaiscript_threading.hpp b/include/chaiscript/chaiscript_threading.hpp
index bfc7d6c..85cba1d 100644
--- a/include/chaiscript/chaiscript_threading.hpp
+++ b/include/chaiscript/chaiscript_threading.hpp
@@ -23,6 +23,7 @@
 
 namespace chaiscript
 {
+  /// \internal
   namespace detail
   {
     namespace threading
diff --git a/include/chaiscript/dispatchkit/handle_return.hpp b/include/chaiscript/dispatchkit/handle_return.hpp
index ba2b381..a79e5b0 100644
--- a/include/chaiscript/dispatchkit/handle_return.hpp
+++ b/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
      */
diff --git a/unittests/assign_const.chai b/unittests/assign_const.chai
new file mode 100644
index 0000000..ff6a8c3
--- /dev/null
+++ b/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 } );