add boost on mac

macx64/include/boost/chrono/detail/system.hpp

@@ -0,0 +1,20 @@
+//  Copyright 2009-2010 Vicente J. Botet Escriba
+
+//  Distributed under the Boost Software License, Version 1.0.
+//  See http://www.boost.org/LICENSE_1_0.txt
+
+#ifndef BOOST_CHRONO_DETAIL_SYSTEM_HPP
+#define BOOST_CHRONO_DETAIL_SYSTEM_HPP
+
+#if !defined BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING
+
+#include <boost/system/error_code.hpp>
+
+namespace boost {
+namespace chrono {
+    inline bool is_throws(system::error_code  & ec) { return (&ec==&boost::throws()); }
+}
+}
+
+#endif
+#endif