diff -Nur boost_1_58_0/boost/thread/future.hpp boost_1_58_0.patched/boost/thread/future.hpp
--- boost_1_58_0/boost/thread/future.hpp	2015-03-21 15:44:02.000000000 +0100
+++ boost_1_58_0.patched/boost/thread/future.hpp	2015-06-30 08:24:38.186298176 +0200
@@ -407,7 +407,7 @@
                 return policy_;
             }
 
-            future_state::state get_state(boost::unique_lock<boost::mutex>& lk) const
+            future_state::state get_state(boost::unique_lock<boost::mutex>& /*lk*/) const
             {
                 if(!done)
                 {