add boost on mac

macx64/include/boost/mpi/error_string.hpp

@@ -0,0 +1,26 @@
+// Copyright (C) 2018 Alain Miniussi <alain.miniussi -at- oca.eu>.
+
+// Use, modification and distribution is subject to 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)
+
+/** @file error_string.hpp
+ *
+ *  Error code to string convertion.
+ */
+#ifndef BOOST_MPI_ERROR_STRING_HPP
+#define BOOST_MPI_ERROR_STRING_HPP
+
+#include <boost/mpi/config.hpp>
+#include <string>
+
+namespace boost { namespace mpi {
+
+/**
+ * @brief Convert a MPI error code to an error string.
+ */
+std::string error_string(int err_code);
+
+} } // end namespace boost::mpi
+
+#endif // BOOST_MPI_ERROR_STRING_HPP