moved from grid/genericgeometry

[[Imported from SVN: r5612]]

common/forloop.hh

+// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+// vi: set et ts=4 sw=2 sts=2:
+#ifndef DUNE_COMMON_FORLOOP_HH
+#define DUNE_COMMON_FORLOOP_HH
+
+#include <dune/common/static_assert.hh>
+
+namespace Dune
+{
+  /** \class ForLoop
+   * @brief A static loop using TMP
+   *
+   * The ForLoop takes a
+   *   \code template<int i> class Operation
+   * template argument with a static apply method
+   * which is called for i=first...last (first<=last are int template arguments).
+   * A specialization for class template class Operation for i=first
+   * or i=last is not required. The class Operation must provide a
+   * static void function apply(...). Arguments (as references)
+   * can be passed through the ForLoop to this function
+   * (up to 5 at the moment).
+   *
+   * It is possible to pass a subclass to the ForLoop
+   * (since no specialization is needed).
+   * Example of usage:
+   * template <class Foo>
+   * struct A
+   * {
+   *   template <int i>
+   *   struct Operation
+   *   {
+   *     template <class T>
+   *     static void apply(const double &x,const T &t, T &ret)
+   *     {
+   *       ret = "hallo" + t;
+   *     }
+   *   };
+   *   void useForLoop()
+   *   {
+   *     std::string world;
+   *     ForLoop<Operation,1,10>::apply(1.,"hallo",world);
+   *   }
+   * };
+   */
+
+  template< template< int > class Operation, int first, int last >
+  struct ForLoop
+  {
+    static void apply ()
+    {
+      Operation< first >::apply();
+      ForLoop< Operation, first+1, last >::apply();
+    }
+
+    template< class T1 >
+    static void apply ( T1 &p1 )
+    {
+      Operation< first >::apply( p1 );
+      ForLoop< Operation, first+1, last >::apply( p1 );
+    }
+
+    template< class T1, class T2 >
+    static void apply ( T1 &p1, T2 &p2 )
+    {
+      Operation< first >::apply( p1, p2 );
+      ForLoop< Operation, first+1, last >::apply( p1, p2 );
+    }
+
+    template< class T1, class T2, class T3 >
+    static void apply ( T1 &p1, T2 &p2, T3 &p3 )
+    {
+      Operation< first >::apply( p1, p2, p3 );
+      ForLoop< Operation, first+1, last >::apply( p1, p2, p3 );
+    }
+
+    template< class T1, class T2, class T3, class T4 >
+    static void apply ( T1 &p1, T2 &p2, T3 &p3, T4 &p4 )
+    {
+      Operation< first >::apply( p1, p2, p3, p4 );
+      ForLoop< Operation, first+1, last >::apply( p1, p2, p3, p4 );
+    }
+
+    template< class T1, class T2, class T3, class T4, class T5 >
+    static void apply ( T1 &p1, T2 &p2, T3 &p3, T4 &p4, T5 &p5 )
+    {
+      Operation< first >::apply( p1, p2, p3, p4, p5 );
+      ForLoop< Operation, first+1, last >::apply( p1, p2, p3, p4, p5 );
+    }
+
+  private:
+    dune_static_assert( (first <= last), "ForLoop: first > last" );
+  };
+
+  template< template< int > class Operation, int last >
+  struct ForLoop< Operation, last, last >
+  {
+    static void apply ()
+    {
+      Operation< last >::apply();
+    }
+
+    template< class T1 >
+    static void apply ( T1 &p1 )
+    {
+      Operation< last >::apply( p1 );
+    }
+
+    template< class T1, class T2 >
+    static void apply ( T1 &p1, T2 &p2 )
+    {
+      Operation< last >::apply( p1, p2 );
+    }
+
+    template< class T1, class T2, class T3 >
+    static void apply ( T1 &p1, T2 &p2, T3 &p3 )
+    {
+      Operation< last >::apply( p1, p2, p3 );
+    }
+
+    template< class T1, class T2, class T3, class T4 >
+    static void apply ( T1 &p1, T2 &p2, T3 &p3, T4 &p4 )
+    {
+      Operation< last >::apply( p1, p2, p3, p4 );
+    }
+
+    template< class T1, class T2, class T3, class T4, class T5 >
+    static void apply ( T1 &p1, T2 &p2, T3 &p3, T4 &p4, T5 &p5 )
+    {
+      Operation< last >::apply( p1, p2, p3, p4, p5 );
+    }
+  };
+
+}
+
+#endif