Index: boost/thread/scoped_thread.hpp
===================================================================
--- boost/thread/scoped_thread.hpp	(revision 83938)
+++ boost/thread/scoped_thread.hpp	(working copy)
@@ -171,6 +171,11 @@
       t_.detach();
     }
 
+    bool joinable() const BOOST_NOEXCEPT
+    {
+      return t_.joinable();
+    }
+
     void join()
     {
       t_.join();