--- boost/thread/locks.hpp	2008-04-22 14:19:03.000000000 -0700
+++ boost/thread/locks.hpp	2008-04-22 15:58:08.000000000 -0700
@@ -54,6 +54,30 @@
 
 
     template<typename Mutex>
+    class unlock_guard
+    {
+    private:
+        Mutex& m;
+
+        explicit unlock_guard(unlock_guard&);
+        unlock_guard& operator=(unlock_guard&);
+    public:
+        explicit unlock_guard(Mutex& m_):
+            m(m_)
+        {
+            m.unlock();
+        }
+        unlock_guard(Mutex& m_,adopt_lock_t):
+            m(m_)
+        {}
+        ~unlock_guard()
+        {
+            m.lock();
+        }
+    };
+
+
+    template<typename Mutex>
     class unique_lock
     {
     private: