Added compile time decision about writing the output

Signed-off-by: Santiago Ospina <saospina@hugo.iwr.uni-heidelberg.de>

dune/dorie/interface/richards_simulation.cc

@@ -57,15 +57,18 @@ RichardsSimulation<Traits>::RichardsSimulation (Dune::MPIHelper& _helper, std::s
 	operator_setup();
 
 	// --- Utility Class Setup --- //
-	const int subsamling_lvl = _inifile.get<int>("output.subsamplingLevel", 0);
-	const auto subsamling_intervals = Dune::refinementLevels(subsamling_lvl);
-	auto sub_vtk = std::make_shared<Dune::SubsamplingVTKWriter<GV>>(gv,
-		subsamling_intervals);
-
-	vtkwriter = std::make_unique<Writer>(sub_vtk,
-						inifile.get<std::string>("output.fileName"),
-						inifile.get<std::string>("output.outputPath"),
-						"./");
+	if constexpr (Traits::write_output)
+	{
+		const int subsamling_lvl = _inifile.get<int>("output.subsamplingLevel", 0);
+		const auto subsamling_intervals = Dune::refinementLevels(subsamling_lvl);
+		auto sub_vtk = std::make_shared<Dune::SubsamplingVTKWriter<GV>>(gv,
+			subsamling_intervals);
+
+		vtkwriter = std::make_unique<Writer>(sub_vtk,
+							inifile.get<std::string>("output.fileName"),
+							inifile.get<std::string>("output.outputPath"),
+							"./");
+	}
 
 	AdaptivityHandlerFactory adaptivity_fac(inifile,*grid);
 	adaptivity = adaptivity_fac.create();
@@ -163,14 +166,17 @@ void RichardsSimulation<Traits>::run ()
 {
 	const auto time = controller->getTime();
 	const RF dt = controller->getDT();
-	write_data(time);
+	
+	if constexpr (Traits::write_output)
+		write_data(time);
 
 	while(controller->doStep()) {
 		if(!compute_time_step()){
 			continue;
 		}
 
-		write_data(controller->getTime());
+		if constexpr (Traits::write_output)
+			write_data(controller->getTime());
 
 		if(controller->doStep()
 		   && adaptivity->adapt_grid(*grid, gv, *gfs, *param, *fboundary,