Moved generic construction to separate file.

[[Imported from SVN: r325]]

istl/paamg/construction.hh

+// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// vi: set et ts=4 sw=2 sts=2:
+#ifndef DUNE_AMGCONSTRUCTION_HH
+#define DUNE_AMGCONSTRUCTION_HH
+
+namespace Dune
+{
+  namespace Amg
+  {
+
+    /**
+     * @addtogroup ISTL_PAAMG
+     *
+     * @{
+     */
+
+    /** @file
+     * @author Markus Blatt
+     * @brief Helper classes for the construction of classes without
+     * empty constructor.
+     */
+    /**
+     * @brief Traits class for generically constructing non default
+     * constructable types.
+     *
+     * Needed because BCRSMatrix and Vector do a deep copy which is
+     * too expensive.
+     */
+    template<typename T>
+    class ConstructionTraits
+    {
+    public:
+      /**
+       * @brief A type holding all the arguments needed to call the
+       * constructor.
+       */
+      typedef const void* Arguments;
+
+      /**
+       * @brief Construct an object with the specified arguments.
+       *
+       * In the default implementation the copy constructor is called.
+       * @param object Pointer to the space allocated for the object.
+       * @param arguments The arguments for the construction.
+       */
+      static inline T* construct(Arguments&  args)
+      {
+        return new T();
+      }
+    };
+
+    template<class T>
+    class ConstructionTraits<BlockVector<T> >
+    {
+    public:
+      typedef const int Arguments;
+      static inline BlockVector<T>* construct(Arguments& n)
+      {
+        return new BlockVector<T>(n);
+      }
+    };
+
+    /** @} */
+  } // namespace Amg
+} // namespace Dune
+#endif

istl/paamg/hierarchy.hh

@@ -22,6 +22,7 @@
 #include <dune/istl/paamg/graph.hh>
 #include <dune/istl/paamg/indicescoarsener.hh>
 #include <dune/istl/paamg/globalaggregates.hh>
+#include <dune/istl/paamg/construction.hh>
 
 namespace Dune
 {

istl/paamg/test/galerkintest.cc

@@ -127,6 +127,6 @@ void testCoarsenIndices()
 int main(int argc, char **argv)
 {
   MPI_Init(&argc, &argv);
-  testCoarsenIndices<3,1>();
+  testCoarsenIndices<10,2>();
   MPI_Finalize();
 }