--- boost/thread/locks.hpp    (revision 61052) 
+++ boost/thread/locks.hpp    (working copy)
@@ -214,7 +214,7 @@
         unique_lock& operator=(unique_lock&);
         unique_lock& operator=(upgrade_lock<Mutex>& other);
     public:
-#ifdef __SUNPRO_CC
+#if BOOST_WORKAROUND(__SUNPRO_CC, < 0x5100)
         unique_lock(const volatile unique_lock&);
 #endif
         unique_lock():
@@ -300,7 +300,7 @@
             return detail::thread_move_t<unique_lock<Mutex> >(*this);
         }

-#ifdef __SUNPRO_CC
+#if BOOST_WORKAROUND(__SUNPRO_CC, < 0x5100)
         unique_lock& operator=(unique_lock<Mutex> other)
         {
             swap(other);