[staggered] Add traits to check whether a grid is twist-free

dumux/discretization/facecentered/staggered/consistentlyorientedgrid.hh

+// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+// vi: set et ts=4 sw=4 sts=4:
+/*****************************************************************************
+ *   See the file COPYING for full copying permissions.                      *
+ *                                                                           *
+ *   This program is free software: you can redistribute it and/or modify    *
+ *   it under the terms of the GNU General Public License as published by    *
+ *   the Free Software Foundation, either version 3 of the License, or       *
+ *   (at your option) any later version.                                     *
+ *                                                                           *
+ *   This program is distributed in the hope that it will be useful,         *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of          *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the            *
+ *   GNU General Public License for more details.                            *
+ *                                                                           *
+ *   You should have received a copy of the GNU General Public License       *
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>.   *
+ *****************************************************************************/
+/*!
+ * \file
+ * \ingroup Typetraits
+ * \copydoc Type trait to determine if a grid is oriented consistently
+ */
+#ifndef DUMUX_DISCRETIZATION_FACECENTERED_STAGGERED_CONSISTENTLY_ORIENTED_GRID_HH
+#define DUMUX_DISCRETIZATION_FACECENTERED_STAGGERED_CONSISTENTLY_ORIENTED_GRID_HH
+
+#include <type_traits>
+
+// forward declare
+namespace Dune {
+template<int dim, class Coordinates>
+class YaspGrid;
+
+template <int dim, class HostGrid, bool mapIndexStorage>
+class SubGrid;
+
+}
+
+namespace Dumux {
+
+/*!
+ * \brief Helper type to determine whether a grid is guaranteed to be oriented consistently.
+ *        This means that the intersection indices always correspond to the ones of a reference element
+ *        or, in other words, the elements are never rotated.
+ */
+template<class T>
+struct ConsistentlyOrientedGrid : public std::false_type {};
+
+template<int dim, class Coords>
+struct ConsistentlyOrientedGrid<Dune::YaspGrid<dim, Coords>> : public std::true_type {};
+
+template<int dim, class Coords, bool mapIndexStorage>
+struct ConsistentlyOrientedGrid<Dune::SubGrid<dim, Dune::YaspGrid<dim, Coords>, mapIndexStorage>> : public std::true_type {};
+
+
+} // end namespace Dumux
+
+#endif