--- a/b/boost/boost/signals2/detail/auto_buffer.hpp.sav	2011-12-21 04:05:37.000000000 +0100
+++ a/b/boost/boost/signals2/detail/auto_buffer.hpp	2014-09-13 23:58:51.221215911 +0200
@@ -99,7 +99,7 @@ namespace detail
         }
 
         template< class SizeType >
-        static bool should_shrink( SizeType size, SizeType capacity )
+        static bool should_shrink( __attribute__ ((unused)) SizeType size, __attribute__ ((unused)) SizeType capacity )
         {
             //
             // @remark: when defining a new grow policy, one might
@@ -258,7 +258,7 @@ namespace detail
                 auto_buffer_destroy( buffer );
         }
 
-        void destroy_back_n( size_type n, const boost::true_type& )
+        void destroy_back_n( __attribute__ ((unused)) size_type n, const boost::true_type& )
         { }
 
         void destroy_back_n( size_type n )