Index: detail/thread.hpp
===================================================================
--- detail/thread.hpp	(revision 76011)
+++ detail/thread.hpp	(working copy)
@@ -25,6 +25,8 @@
 #include <boost/utility/enable_if.hpp>
 #include <boost/type_traits/remove_reference.hpp>
 #include <boost/io/ios_state.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/decay.hpp>
 
 #include <boost/config/abi_prefix.hpp>
 
@@ -37,6 +39,33 @@
 {
     namespace detail
     {
+
+#ifndef BOOST_NO_RVALUE_REFERENCES
+
+      template <typename F>
+      F&& forward(typename boost::remove_reference<F>::type& f)
+      {
+        return static_cast<F&&>(f);
+      }
+      template <typename F>
+      F&& forward(typename boost::remove_reference<F>::type&& f)
+      {
+        return static_cast<F&&>(f);
+      }
+
+      template <class T>
+      typename decay<T>::type
+      decay_copy(T&& t)
+      {
+          return forward<T>(t);
+      }
+
+#endif
+
+
+
+
+
         template<typename F>
         class thread_data:
             public detail::thread_data_base
@@ -44,11 +73,13 @@
         public:
 #ifndef BOOST_NO_RVALUE_REFERENCES
             thread_data(F&& f_):
-                f(static_cast<F&&>(f_))
+              //f(static_cast<F&&>(f_))
+              f(detail::forward<F>(f_))
             {}
-            thread_data(F& f_):
-                f(f_)
-            {}
+// This overloading must be removed if we want the packaged_task's tests to pass.
+//            thread_data(F& f_):
+//                f(f_)
+//            {}
 #else
             thread_data(F f_):
                 f(f_)
@@ -128,11 +159,15 @@
         template<typename F>
         static inline detail::thread_data_ptr make_thread_info(F&& f)
         {
-            return detail::thread_data_ptr(detail::heap_new<detail::thread_data<typename boost::remove_reference<F>::type> >(static_cast<F&&>(f)));
+          //return detail::thread_data_ptr(detail::heap_new<detail::thread_data<typename boost::remove_reference<F>::type> >(static_cast<F&&>(f)));
+            return detail::thread_data_ptr(detail::heap_new<detail::thread_data<typename boost::remove_reference<F>::type> >(
+                detail::forward<F>(f)));
         }
         static inline detail::thread_data_ptr make_thread_info(void (*f)())
         {
-            return detail::thread_data_ptr(detail::heap_new<detail::thread_data<void(*)()> >(static_cast<void(*&&)()>(f)));
+            //return detail::thread_data_ptr(detail::heap_new<detail::thread_data<void(*)()> >(static_cast<void(*&&)()>(f)));
+            return detail::thread_data_ptr(detail::heap_new<detail::thread_data<void(*)()> >(
+                detail::forward<void(*)()>(f)));
         }
 #else
         template<typename F>
@@ -164,9 +199,13 @@
             start_thread();
         }
 #else
-        template <class F>
-        thread(F&& f):
-            thread_info(make_thread_info(static_cast<F&&>(f)))
+        template <
+          class F,
+          class Dummy = typename disable_if< is_same<typename decay<F>::type, thread> >::type
+        >
+        explicit thread(F&& f):
+          //thread_info(make_thread_info(static_cast<F&&>(f)))
+          thread_info(make_thread_info(detail::decay_copy(detail::forward<F>(f))))
         {
             start_thread();
         }