diff -ru boost.orig/boost/signals2/connection.hpp boost/boost/signals2/connection.hpp
--- foo/misc/boost.orig/boost/signals2/connection.hpp	2015-07-09 20:06:58.000000000 +0200
+++ foo/misc/boost/boost/signals2/connection.hpp	2015-07-19 21:54:54.491994554 +0200
@@ -68,12 +68,12 @@
           nolock_disconnect(local_lock);
         }
         template<typename Mutex>
-        void nolock_disconnect(garbage_collecting_lock<Mutex> &lock) const
+        void nolock_disconnect(garbage_collecting_lock<Mutex> &lock_) const
         {
           if(_connected)
           {
             _connected = false;
-            dec_slot_refcount(lock);
+            dec_slot_refcount(lock_);
           }
         }
         virtual bool connected() const = 0;
@@ -118,12 +118,12 @@
         // shared_ptr to the slot in the garbage collecting lock,
         // which will destroy the slot only after it unlocks.
         template<typename Mutex>
-        void dec_slot_refcount(garbage_collecting_lock<Mutex> &lock) const
+        void dec_slot_refcount(garbage_collecting_lock<Mutex> &lock_arg) const
         {
           BOOST_ASSERT(m_slot_refcount != 0);
           if(--m_slot_refcount == 0)
           {
-            lock.add_trash(release_slot());
+            lock_arg.add_trash(release_slot());
           }
         }
 
@@ -155,17 +155,17 @@
         const GroupKey& group_key() const {return _group_key;}
         void set_group_key(const GroupKey &key) {_group_key = key;}
         template<typename M>
-        void disconnect_expired_slot(garbage_collecting_lock<M> &lock)
+        void disconnect_expired_slot(garbage_collecting_lock<M> &lock_arg)
         {
           if(!m_slot) return;
           bool expired = slot().expired();
           if(expired == true)
           {
-            nolock_disconnect(lock);
+            nolock_disconnect(lock_arg);
           }
         }
         template<typename M, typename OutputIterator>
-        void nolock_grab_tracked_objects(garbage_collecting_lock<M> &lock,
+        void nolock_grab_tracked_objects(garbage_collecting_lock<M> &lock_arg,
           OutputIterator inserter) const
         {
           if(!m_slot) return;
@@ -184,7 +184,7 @@
             );
             if(apply_visitor(detail::expired_weak_ptr_visitor(), *it))
             {
-              nolock_disconnect(lock);
+              nolock_disconnect(lock_arg);
               return;
             }
             *inserter++ = locked_object;