Address more appearances.

source/grid/grid_generator.cc

@@ -5479,8 +5479,7 @@ namespace GridGenerator
   {
     Triangulation<spacedim> volume_mesh;
     GridGenerator::hyper_ball(volume_mesh, p, radius);
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
     GridGenerator::extract_boundary_mesh(volume_mesh, tria, boundary_ids);
     tria.set_all_manifold_ids(0);
     tria.set_manifold(0, SphericalManifold<spacedim - 1, spacedim>(p));

tests/bits/anna_4.cc

@@ -189,9 +189,8 @@ FindBug<dim>::dirichlet_conditions()
                                            component_mask);
 
 
-  std::vector<bool>            fixed_dofs(dof_handler.n_dofs());
-  std::set<types::boundary_id> boundary_ids;
-  boundary_ids.insert(0);
+  std::vector<bool>                  fixed_dofs(dof_handler.n_dofs());
+  const std::set<types::boundary_id> boundary_ids = {0};
 
   // get a list of those boundary DoFs which
   // we want to be fixed:

tests/bits/anna_6.cc

@@ -180,9 +180,8 @@ ImposeBC<dim>::test_extract_boundary_DoFs()
   bc_component_select[1] = true;
   bc_component_select[2] = false;
 
-  std::vector<bool>            ned_boundary_dofs(dof_handler.n_dofs());
-  std::set<types::boundary_id> boundary_ids;
-  boundary_ids.insert(0);
+  std::vector<bool>                  ned_boundary_dofs(dof_handler.n_dofs());
+  const std::set<types::boundary_id> boundary_ids = {0};
   DoFTools::extract_boundary_dofs(dof_handler,
                                   bc_component_select,
                                   ned_boundary_dofs,
@@ -219,9 +218,8 @@ ImposeBC<dim>::test_interpolate_BC()
   // check
   // (the pressure is assumed to be set to 1
   // on the boundary)
-  std::vector<bool>            p_boundary_dofs(dof_handler.n_dofs());
-  std::set<types::boundary_id> boundary_ids;
-  boundary_ids.insert(0);
+  std::vector<bool>                  p_boundary_dofs(dof_handler.n_dofs());
+  const std::set<types::boundary_id> boundary_ids = {0};
   DoFTools::extract_boundary_dofs(dof_handler,
                                   bc_component_select,
                                   p_boundary_dofs,

tests/codim_one/boundary_indicator_01.cc

@@ -90,8 +90,7 @@ main()
 
     // now extract a mesh of the 5
     // surface faces
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
     GridGenerator::extract_boundary_mesh(volume_mesh,
                                          boundary_mesh,
                                          boundary_ids);

tests/codim_one/data_out_03.cc

@@ -90,9 +90,7 @@ main()
   tria.set_manifold(1, surface_description);
   tria.set_manifold(0, surface_description);
 
-  std::set<types::boundary_id> boundary_ids;
-  boundary_ids.insert(0);
-
+  const std::set<types::boundary_id> boundary_ids = {0};
   GridGenerator::extract_boundary_mesh(volume_mesh, tria, boundary_ids);
 
   // test for the position

tests/codim_one/extract_boundary_mesh_00.cc

@@ -115,9 +115,8 @@ main()
 
     save_mesh(volume_mesh);
 
-    Triangulation<dim - 1, dim> boundary_mesh;
-    set<types::boundary_id>     boundary_ids;
-    boundary_ids.insert(0);
+    Triangulation<dim - 1, dim>   boundary_mesh;
+    const set<types::boundary_id> boundary_ids = {0};
 
     surface_to_volume_mapping =
       GridGenerator::extract_boundary_mesh(volume_mesh,

tests/codim_one/extract_boundary_mesh_07.cc

@@ -81,8 +81,7 @@ namespace Step38
   Extract_Mesh_Test<spacedim>::run()
   {
     GridGenerator::hyper_cube(volume_mesh_triangulation);
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
 
     space_dof_handler.distribute_dofs(space_fe);
 

tests/codim_one/hanging_nodes_01.cc

@@ -55,8 +55,7 @@ main()
       volume_mesh.begin_active();
 
     cell->face(0)->set_all_boundary_ids(1);
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
     GridGenerator::extract_boundary_mesh(volume_mesh,
                                          boundary_mesh,
                                          boundary_ids);

tests/codim_one/hanging_nodes_02.cc

@@ -52,8 +52,7 @@ main()
       volume_mesh.begin_active();
 
     cell->face(0)->set_all_boundary_ids(1);
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
     GridGenerator::extract_boundary_mesh(volume_mesh,
                                          boundary_mesh,
                                          boundary_ids);

tests/codim_one/hanging_nodes_03.cc

@@ -46,8 +46,7 @@ main()
       volume_mesh.begin_active();
 
     cell->face(0)->set_all_boundary_ids(1);
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
     GridGenerator::extract_boundary_mesh(volume_mesh,
                                          boundary_mesh,
                                          boundary_ids);

tests/codim_one/interpolate_boundary_values_03.cc

@@ -43,9 +43,7 @@ test()
   Triangulation<dim, spacedim> tria;
   Triangulation<spacedim>      volume_mesh;
   GridGenerator::half_hyper_ball(volume_mesh);
-  std::set<types::boundary_id> boundary_ids;
-  boundary_ids.insert(0);
-
+  const std::set<types::boundary_id> boundary_ids = {0};
   GridGenerator::extract_boundary_mesh(volume_mesh, tria, boundary_ids);
 
   deallog << tria.n_active_cells() << " active cells" << std::endl;

tests/codim_one/transform_01.cc

@@ -70,9 +70,7 @@ main()
   static SphericalManifold<3 - 1, 3> surface_description;
   triangulation.set_manifold(0, surface_description);
 
-  std::set<types::boundary_id> boundary_ids;
-  boundary_ids.insert(0);
-
+  const std::set<types::boundary_id> boundary_ids = {0};
   GridGenerator::extract_boundary_mesh(volume_mesh,
                                        triangulation,
                                        boundary_ids);

tests/dofs/dof_tools_05.cc

@@ -52,8 +52,7 @@ check_this(const DoFHandler<dim> &dof_handler)
   // third further restrict to
   // boundary indicator 0
   {
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
     DoFTools::extract_boundary_dofs(dof_handler,
                                     component_select,
                                     boundary_dofs,

tests/dofs/dof_tools_09.cc

@@ -30,10 +30,9 @@ void
 check_this(const DoFHandler<dim> &dof_handler)
 {
   std::vector<types::global_dof_index> map(dof_handler.n_dofs());
-  std::set<types::boundary_id>         boundary_ids;
-
   // check for boundary id 0 alone
-  boundary_ids.insert(0);
+  const std::set<types::boundary_id> boundary_ids = {0};
+
   DoFTools::map_dof_to_boundary_indices(dof_handler, map);
   for (unsigned int i = 0; i < map.size(); ++i)
     deallog << (map[i] == numbers::invalid_dof_index ?

tests/dofs/dof_tools_14.cc

@@ -38,7 +38,6 @@ check_this(const DoFHandler<dim> &dof_handler)
   deallog << dof_handler.n_boundary_dofs(fm) << std::endl;
 
   // with std::set
-  std::set<types::boundary_id> s;
-  s.insert(0);
+  const std::set<types::boundary_id> s = {0};
   deallog << dof_handler.n_boundary_dofs(s) << std::endl;
 }

tests/dofs/dof_tools_16a.cc

@@ -40,8 +40,7 @@ check_this(const DoFHandler<dim> &dof_handler)
     return;
 
   std::vector<types::global_dof_index> map(dof_handler.n_dofs());
-  std::set<types::boundary_id>         set;
-  set.insert(0);
+  const std::set<types::boundary_id>   set = {0};
   DoFTools::map_dof_to_boundary_indices(dof_handler, set, map);
 
   // create sparsity pattern

tests/dofs/dof_tools_16b.cc

@@ -40,8 +40,7 @@ check_this(const DoFHandler<dim> &dof_handler)
     return;
 
   std::vector<types::global_dof_index> map(dof_handler.n_dofs());
-  std::set<types::boundary_id>         set;
-  set.insert(0);
+  const std::set<types::boundary_id>   set = {0};
   DoFTools::map_dof_to_boundary_indices(dof_handler, set, map);
 
   // create sparsity pattern

tests/dofs/dof_tools_16c.cc

@@ -40,8 +40,7 @@ check_this(const DoFHandler<dim> &dof_handler)
     return;
 
   std::vector<types::global_dof_index> map(dof_handler.n_dofs());
-  std::set<types::boundary_id>         set;
-  set.insert(0);
+  const std::set<types::boundary_id>   set = {0};
   DoFTools::map_dof_to_boundary_indices(dof_handler, set, map);
 
   std::map<types::boundary_id, const Function<dim> *> boundary_ids;

tests/dofs/dof_tools_16d.cc

@@ -40,8 +40,7 @@ check_this(const DoFHandler<dim> &dof_handler)
     return;
 
   std::vector<types::global_dof_index> map(dof_handler.n_dofs());
-  std::set<types::boundary_id>         set;
-  set.insert(0);
+  const std::set<types::boundary_id>   set = {0};
   DoFTools::map_dof_to_boundary_indices(dof_handler, set, map);
 
   std::map<types::boundary_id, const Function<dim> *> boundary_ids;

tests/dofs/dof_tools_20.cc

@@ -52,8 +52,7 @@ check_this(const DoFHandler<dim> &dof_handler)
   // third further restrict to
   // boundary indicator 0
   {
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
     DoFTools::extract_dofs_with_support_on_boundary(dof_handler,
                                                     component_select,
                                                     boundary_dofs,

tests/dofs/interpolate_boundary_values_01.cc

@@ -151,9 +151,8 @@ FindBug<dim>::dirichlet_conditions()
                                            component_mask);
 
 
-  std::vector<bool>            fixed_dofs(dof_handler.n_dofs());
-  std::set<types::boundary_id> boundary_ids;
-  boundary_ids.insert(0);
+  std::vector<bool>                  fixed_dofs(dof_handler.n_dofs());
+  const std::set<types::boundary_id> boundary_ids = {0};
 
   // get a list of those boundary DoFs which
   // we want to be fixed:

tests/examples/step-56.cc

@@ -537,8 +537,7 @@ namespace Step56
         // sparsity patterns and matrices for each level. The resize()
         // function of MGLevelObject<T> will destroy all existing contained
         // objects.
-        std::set<types::boundary_id> zero_boundary_ids;
-        zero_boundary_ids.insert(0);
+        const std::set<types::boundary_id> zero_boundary_ids = {0};
 
         mg_constrained_dofs.clear();
         mg_constrained_dofs.initialize(velocity_dof_handler);

tests/manifold/tensor_product_manifold_02.cc

@@ -40,8 +40,7 @@ test()
   {
     Triangulation<3, 3> volume_tria;
     GridGenerator::cylinder(volume_tria);
-    std::set<types::boundary_id> boundary_ids;
-    boundary_ids.insert(0);
+    const std::set<types::boundary_id> boundary_ids = {0};
     GridGenerator::extract_boundary_mesh(volume_tria, tria, boundary_ids);
   }
   tria.set_all_manifold_ids(0);

tests/mappings/mapping_q_eulerian_08.cc

@@ -276,9 +276,8 @@ test(const unsigned int n_ref = 0)
   }
 
   // now go through all GMG levels:
-  std::set<types::boundary_id> dirichlet_boundary_ids;
-  dirichlet_boundary_ids.insert(0);
-  MGConstrainedDoFs mg_constrained_dofs;
+  const std::set<types::boundary_id> dirichlet_boundary_ids = {0};
+  MGConstrainedDoFs                  mg_constrained_dofs;
   mg_constrained_dofs.initialize(dof_handler);
   mg_constrained_dofs.make_zero_boundary_constraints(dof_handler,
                                                      dirichlet_boundary_ids);

tests/mappings/mapping_q_eulerian_14.cc

@@ -316,9 +316,8 @@ test(const unsigned int n_ref = 0)
   }
 
   // now go through all GMG levels:
-  std::set<types::boundary_id> dirichlet_boundary_ids;
-  dirichlet_boundary_ids.insert(0);
-  MGConstrainedDoFs mg_constrained_dofs;
+  const std::set<types::boundary_id> dirichlet_boundary_ids = {0};
+  MGConstrainedDoFs                  mg_constrained_dofs;
   mg_constrained_dofs.initialize(dof_handler);
   mg_constrained_dofs.make_zero_boundary_constraints(dof_handler,
                                                      dirichlet_boundary_ids);

tests/matrix_free/copy_feevaluation.cc

@@ -172,7 +172,7 @@ test()
   stokes_sub_blocks[dim] = 1;
   DoFRenumbering::component_wise(dof_handler, stokes_sub_blocks);
 
-  std::set<types::boundary_id> no_normal_flux_boundaries = {1};
+  const std::set<types::boundary_id> no_normal_flux_boundaries = {1};
   DoFTools::make_hanging_node_constraints(dof_handler, constraints);
   VectorTools::compute_no_normal_flux_constraints(
     dof_handler, 0, no_normal_flux_boundaries, constraints, mapping);

tests/meshworker/step-50-mesh_loop.cc

@@ -240,10 +240,9 @@ namespace Step50
     constraints.reinit(locally_relevant_set);
     DoFTools::make_hanging_node_constraints(mg_dof_handler, constraints);
 
-    std::set<types::boundary_id>                        dirichlet_boundary_ids;
+    const std::set<types::boundary_id> dirichlet_boundary_ids = {0};
     std::map<types::boundary_id, const Function<dim> *> dirichlet_boundary;
     Functions::ConstantFunction<dim> homogeneous_dirichlet_bc(1.0);
-    dirichlet_boundary_ids.insert(0);
     dirichlet_boundary[0] = &homogeneous_dirichlet_bc;
     VectorTools::interpolate_boundary_values(mg_dof_handler,
                                              dirichlet_boundary,

tests/mpi/no_flux_constraints_03.cc

@@ -90,9 +90,8 @@ test()
   AffineConstraints<double> constraints;
   constraints.reinit(relevant_set);
   DoFTools::make_hanging_node_constraints(dofh, constraints);
-  std::set<types::boundary_id> no_normal_flux_boundaries;
-  no_normal_flux_boundaries.insert(0);
-  const unsigned int degree = 1;
+  const std::set<types::boundary_id> no_normal_flux_boundaries = {0};
+  const unsigned int                 degree                    = 1;
   VectorTools::compute_no_normal_flux_constraints(
     dofh, 0, no_normal_flux_boundaries, constraints, MappingQ<dim>(degree));
   constraints.close();

tests/mpi/step-37.cc

@@ -244,8 +244,7 @@ namespace Step37
     const unsigned int nlevels = triangulation.n_global_levels();
     mg_matrices.resize(0, nlevels - 1);
 
-    std::set<types::boundary_id> dirichlet_boundary;
-    dirichlet_boundary.insert(0);
+    const std::set<types::boundary_id> dirichlet_boundary = {0};
     mg_constrained_dofs.initialize(dof_handler);
     mg_constrained_dofs.make_zero_boundary_constraints(dof_handler,
                                                        dirichlet_boundary);
@@ -325,11 +324,10 @@ namespace Step37
       DoFTools::make_hanging_node_constraints(
         dof_handler, hanging_nodes_laplace_constraints);
 
-      std::set<types::boundary_id> dirichlet_boundary_ids;
+      const std::set<types::boundary_id> dirichlet_boundary_ids = {0};
       std::map<types::boundary_id, const Function<dim> *>
                                dirichlet_boundary_functions;
       PotentialBCFunction<dim> bc_func(240, Point<dim>());
-      dirichlet_boundary_ids.insert(0);
       dirichlet_boundary_functions[0] = &bc_func;
       VectorTools::interpolate_boundary_values(*mapping.get(),
                                                dof_handler,

tests/multigrid-global-coarsening/multigrid_a_02.cc

@@ -54,9 +54,8 @@ test(const unsigned int n_refinements, const unsigned int fe_degree_fine)
   dof_handler.distribute_dofs(*fe);
   dof_handler.distribute_mg_dofs();
 
-  std::set<types::boundary_id> dirichlet_boundary;
-  dirichlet_boundary.insert(0);
-  MGConstrainedDoFs mg_constrained_dofs;
+  const std::set<types::boundary_id> dirichlet_boundary = {0};
+  MGConstrainedDoFs                  mg_constrained_dofs;
   mg_constrained_dofs.initialize(dof_handler);
   mg_constrained_dofs.make_zero_boundary_constraints(dof_handler,
                                                      dirichlet_boundary);

tests/multigrid-global-coarsening/multigrid_p_02.cc

@@ -73,9 +73,8 @@ test(const unsigned int n_refinements, const unsigned int fe_degree_fine)
       dof_handler.distribute_mg_dofs();
 
       // set up constraints
-      std::set<types::boundary_id> dirichlet_boundary;
-      dirichlet_boundary.insert(0);
-      MGConstrainedDoFs mg_constrained_dofs;
+      const std::set<types::boundary_id> dirichlet_boundary = {0};
+      MGConstrainedDoFs                  mg_constrained_dofs;
       mg_constrained_dofs.initialize(dof_handler);
       mg_constrained_dofs.make_zero_boundary_constraints(dof_handler,
                                                          dirichlet_boundary);

tests/multigrid-global-coarsening/multigrid_p_03.cc

@@ -76,9 +76,8 @@ test(const unsigned int n_refinements,
       dof_handler.distribute_mg_dofs();
 
       // set up constraints
-      std::set<types::boundary_id> dirichlet_boundary;
-      dirichlet_boundary.insert(0);
-      MGConstrainedDoFs mg_constrained_dofs;
+      const std::set<types::boundary_id> dirichlet_boundary = {0};
+      MGConstrainedDoFs                  mg_constrained_dofs;
       mg_constrained_dofs.initialize(dof_handler);
       mg_constrained_dofs.make_zero_boundary_constraints(dof_handler,
                                                          dirichlet_boundary);

tests/multigrid/constrained_dofs_03.cc

@@ -58,10 +58,8 @@ check_fe(FiniteElement<dim> &fe, ComponentMask &component_mask)
   dofh.distribute_dofs(fe);
   dofh.distribute_mg_dofs();
 
-  MGConstrainedDoFs            mg_constrained_dofs;
-  std::set<types::boundary_id> boundary_indicators;
-
-  boundary_indicators.insert(0);
+  MGConstrainedDoFs                  mg_constrained_dofs;
+  const std::set<types::boundary_id> boundary_indicators = {0};
   mg_constrained_dofs.initialize(dofh);
   mg_constrained_dofs.make_zero_boundary_constraints(dofh,
                                                      boundary_indicators,

tests/multigrid/interface_matrix_entry_01.cc

@@ -94,10 +94,9 @@ test()
   constraints.reinit(locally_relevant_set);
   DoFTools::make_hanging_node_constraints(mg_dof_handler, constraints);
 
-  std::set<types::boundary_id>                        dirichlet_boundary_ids;
+  const std::set<types::boundary_id> dirichlet_boundary_ids = {0};
   std::map<types::boundary_id, const Function<dim> *> dirichlet_boundary;
   Functions::ConstantFunction<dim> homogeneous_dirichlet_bc(0.0);
-  dirichlet_boundary_ids.insert(0);
   dirichlet_boundary[0] = &homogeneous_dirichlet_bc;
   VectorTools::interpolate_boundary_values(mg_dof_handler,
                                            dirichlet_boundary,