Put Torus in Curved namespace

src/example6.cc

@@ -19,7 +19,8 @@
 #include <dune/grid/yaspgrid.hh>
 #include <dune/grid/io/file/vtk.hh>
 
-using namespace Dune;
+namespace Dune {
+namespace Curved {
 
 struct Torus
 {
@@ -47,8 +48,12 @@ struct Torus
   }
 };
 
+}}
+
 int main(int argc, char** argv)
 {
+  using namespace Dune;
+
   MPIHelper::instance(argc, argv);
 
   // 1. Construct a reference grid [0,1]x[0,1]
@@ -58,7 +63,7 @@ int main(int argc, char** argv)
   CurvedGrid grid1{grid0, [](auto const& x) { return (2.0*M_PI)*x; }, 1};
 
   // 2. Define the geometry mapping
-  auto torus = Torus{};
+  auto torus = Curved::Torus{};
 
   // 3. Wrap the reference grid to build a curved grid, with Lagrange elements of order 3
   CurvedGrid grid2{grid1, torus};