add boost on mac

macx64/include/boost/metaparse/v1/cpp11/nth_of.hpp

@@ -0,0 +1,24 @@
+#ifndef BOOST_METAPARSE_V1_CPP11_NTH_OF_HPP
+#define BOOST_METAPARSE_V1_CPP11_NTH_OF_HPP
+
+// Copyright Abel Sinkovics (abel@sinkovics.hu)  2017.
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/metaparse/v1/nth_of_c.hpp>
+
+namespace boost
+{
+  namespace metaparse
+  {
+    namespace v1
+    {
+      template <class K, class... Ps>
+      struct nth_of : nth_of_c<K::type::value, Ps...> {};
+    }
+  }
+}
+
+#endif
+