Incorporate Promote from Arithmetic/StaticMatrix

dune/matrix-vector/CMakeLists.txt

@@ -8,6 +8,7 @@ install(FILES
   genericvectortools.hh
   ldlt.hh
   matrixtraits.hh
+  promote.hh
   scalartraits.hh
   singlenonzerocolumnmatrix.hh
   singlenonzerorowmatrix.hh

dune/matrix-vector/promote.hh

+#ifndef DUNE_MATRIX_VECTOR_PROMOTE_HH
+#define DUNE_MATRIX_VECTOR_PROMOTE_HH
+
+#include <dune/common/diagonalmatrix.hh>
+#include <dune/common/fmatrix.hh>
+#include <dune/istl/scaledidmatrix.hh>
+
+namespace Dune {
+namespace MatrixVector {
+  // type promotion (smallest matrix that can hold the sum of two matrices
+  // *******************
+  template <class MatrixA, class MatrixB>
+  struct Promote {
+    typedef Dune::FieldMatrix<typename MatrixA::field_type, MatrixA::rows,
+                              MatrixA::cols>
+        Type;
+  };
+
+  template <class Matrix>
+  struct Promote<Matrix, Matrix> {
+    typedef Matrix Type;
+  };
+
+  template <typename FieldType, int n>
+  struct Promote<Dune::FieldMatrix<FieldType, n, n>,
+                 Dune::DiagonalMatrix<FieldType, n>> {
+    typedef Dune::FieldMatrix<FieldType, n, n> Type;
+  };
+
+  template <typename FieldType, int n>
+  struct Promote<Dune::DiagonalMatrix<FieldType, n>,
+                 Dune::FieldMatrix<FieldType, n, n>> {
+    typedef Dune::FieldMatrix<FieldType, n, n> Type;
+  };
+
+  template <typename FieldType, int n>
+  struct Promote<Dune::DiagonalMatrix<FieldType, n>,
+                 Dune::ScaledIdentityMatrix<FieldType, n>> {
+    typedef Dune::DiagonalMatrix<FieldType, n> Type;
+  };
+
+  template <typename FieldType, int n>
+  struct Promote<Dune::ScaledIdentityMatrix<FieldType, n>,
+                 Dune::DiagonalMatrix<FieldType, n>> {
+    typedef Dune::DiagonalMatrix<FieldType, n> Type;
+  };
+}
+}
+
+#endif