Step-37: small update to the documentation

diff --git a/examples/step-37/doc/intro.dox b/examples/step-37/doc/intro.dox
index e302529e4d28ae7c155f79d78c96570d49f276ce..e60666c0d516d375c07d7ca70d8b281335353b6f 100644 (file)
--- a/examples/step-37/doc/intro.dox
+++ b/examples/step-37/doc/intro.dox
@@ -114,10 +114,7 @@ Matrixfree<dim>::vmult (Vector<double>       &dst,
 
   std::vector<unsigned int> local_dof_indices (dofs_per_cell);
 
-  typename DoFHandler<dim>::active_cell_iterator
-    cell = dof_handler.begin_active(),
-    endc = dof_handler.end();
-  for (; cell!=endc; ++cell)
+  for (const auto & cell : dof_handler.active_cell_iterators())
     {
       cell_matrix = 0;
       fe_values.reinit (cell);
@@ -257,7 +254,6 @@ v = \sum_{\mathrm{cell}=1}^{\mathrm{n\_cells}} P_\mathrm{cell,{loc-glob}}^T
 v_\mathrm{cell}.
 @f}
 @code
-...
   FEValues<dim> fe_values_reference (fe, quadrature_formula,
                                      update_gradients);
   Triangulation<dim> reference_cell;
@@ -268,7 +264,7 @@ v_\mathrm{cell}.
                            update_inverse_jacobians | update_JxW_values |
                            update_quadrature_points);
 
-  for (; cell!=endc; ++cell)
+  for (const auto & cell : dof_handler.active_cell_iterators())
     {
       fe_values.reinit (cell);
       coefficient.value_list(fe_values.get_quadrature_points(),