First incompomplete skectch of apossible cartesian communicator.

src/cartesian_communicator.cpp

@@ -0,0 +1,27 @@
+// Copyright (C) 2014 Alain Miniussi.
+
+// 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)
+#include <boost/mpi/cartesian_communicator.hpp>
+
+namespace boost { namespace mpi {
+
+cartesian_communicator::cartesian_communicator(const communicator&      comm,
+                                               const std::vector<int>&  dims,
+                                               const std::vector<bool>& periodic,
+                                               bool                     reorder )
+  : communicator() 
+{
+  BOOST_ASSERT(dims.size() == periodic.size());
+  MPI_Comm newcomm;
+  std::vector<int> p(periodic.begin(), periodic.end());
+  BOOST_MPI_CHECK_RESULT(MPI_Cart_create, 
+                         ((MPI_Comm)comm, dims.size(), 
+                          const_cast<int*>(dims.data()), p.data(), 
+                          int(reorder), &newcomm));
+  if(newcomm != MPI_COMM_NULL) {
+    comm_ptr.reset(new MPI_Comm(newcomm), comm_free());
+  }
+}
+} } // end namespace boost::mpi