In file included from /hpx/opencl/server/device.hpp:19:
/hpx/opencl/server/util/data_map.hpp:110:16: error: no type named 'mutex' in namespace 'boost'
        boost::mutex m;
        ~~~~~~~^
/hpx/opencl/server/util/data_map.hpp:81:22: error: no member named 'mutex' in namespace 'boost'
                 boost::mutex::scoped_lock lock(this->m);
                 ~~~~~~~^
2 errors generated.