Work around msvc-10.0 ref_fn_test failure.

include/boost/core/ref.hpp

@@ -39,6 +39,12 @@
 namespace boost
 {
 
+#if defined( BOOST_MSVC ) && BOOST_WORKAROUND( BOOST_MSVC, == 1600 )
+
+    struct ref_workaround_tag {};
+
+#endif
+
 // reference_wrapper
 
 /**
@@ -66,6 +72,12 @@ public:
     */
     BOOST_FORCEINLINE explicit reference_wrapper(T& t): t_(boost::addressof(t)) {}
 
+#if defined( BOOST_MSVC ) && BOOST_WORKAROUND( BOOST_MSVC, == 1600 )
+
+    BOOST_FORCEINLINE explicit reference_wrapper( T & t, ref_workaround_tag ): t_( boost::addressof( t ) ) {}
+
+#endif
+
 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
     /**
      @remark Construction from a temporary object is disabled.
@@ -118,7 +130,15 @@ private:
 */
 template<class T> BOOST_FORCEINLINE reference_wrapper<T> BOOST_REF_CONST ref( T & t )
 {
+#if defined( BOOST_MSVC ) && BOOST_WORKAROUND( BOOST_MSVC, == 1600 )
+
+    return reference_wrapper<T>( t, ref_workaround_tag() );
+
+#else
+
     return reference_wrapper<T>( t );
+
+#endif
 }
 
 /**
@@ -127,7 +147,7 @@ template<class T> BOOST_FORCEINLINE reference_wrapper<T> BOOST_REF_CONST ref( T
 */
 template<class T> BOOST_FORCEINLINE reference_wrapper<T> BOOST_REF_CONST ref( reference_wrapper<T> t )
 {
-    return reference_wrapper<T>(t.get());
+    return t;
 }
 
 // cref