Add 'requires' clauses to the rest of the triangulation classes.

diff --git a/include/deal.II/base/template_constraints.h b/include/deal.II/base/template_constraints.h
index 15392d1b28fc79826a226a4afbb6263df288a04c..da9ba1613106620cb88dc9de420e265ff1cc107a 100644 (file)
--- a/include/deal.II/base/template_constraints.h
+++ b/include/deal.II/base/template_constraints.h
@@ -837,16 +837,19 @@ namespace parallel
   namespace distributed
   {
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation;
   }
   namespace shared
   {
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation;
   }
   namespace fullydistributed
   {
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation;
   }
 } // namespace parallel

diff --git a/include/deal.II/distributed/fully_distributed_tria.h b/include/deal.II/distributed/fully_distributed_tria.h
index 7339de6b526636d89c5d0343404ccb7a485245f3..87c93a3a835beec729d5bebc806b871776573b45 100644 (file)
--- a/include/deal.II/distributed/fully_distributed_tria.h
+++ b/include/deal.II/distributed/fully_distributed_tria.h
@@ -107,6 +107,7 @@ namespace parallel
      *       GridTools::collect_periodic_faces()) are supported.
      */
     template <int dim, int spacedim = dim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation
       : public parallel::DistributedTriangulationBase<dim, spacedim>
     {

diff --git a/include/deal.II/distributed/p4est_wrappers.h b/include/deal.II/distributed/p4est_wrappers.h
index 44d3a8c1a74c07f85b41a9c18f97737fff181c1a..c3c46f84e80f66b5f2dc753b6362ff01dc493205 100644 (file)
--- a/include/deal.II/distributed/p4est_wrappers.h
+++ b/include/deal.II/distributed/p4est_wrappers.h
@@ -47,6 +47,7 @@ namespace parallel
   namespace distributed
   {
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation;
   }
 } // namespace parallel

diff --git a/include/deal.II/distributed/shared_tria.h b/include/deal.II/distributed/shared_tria.h
index e3830e8ed131f2fffe70a11779c38ec656f68a69..86897e3097df71b86948434dc84d2491dbf6aa98 100644 (file)
--- a/include/deal.II/distributed/shared_tria.h
+++ b/include/deal.II/distributed/shared_tria.h
@@ -103,6 +103,7 @@ namespace parallel
      * @ingroup distributed
      */
     template <int dim, int spacedim = dim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation
       : public dealii::parallel::TriangulationBase<dim, spacedim>
     {
@@ -402,10 +403,13 @@ namespace parallel
         true_level_subdomain_ids_of_cells;
     };
 
+
+
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     template <class Archive>
-    void
-    Triangulation<dim, spacedim>::load(Archive &ar, const unsigned int version)
+    void Triangulation<dim, spacedim>::load(Archive &          ar,
+                                            const unsigned int version)
     {
       dealii::Triangulation<dim, spacedim>::load(ar, version);
       partition();
@@ -428,6 +432,7 @@ namespace parallel
      * MPI is not available.
      */
     template <int dim, int spacedim = dim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation
       : public dealii::parallel::TriangulationBase<dim, spacedim>
     {

diff --git a/include/deal.II/distributed/tria.h b/include/deal.II/distributed/tria.h
index ccb7e18a2f78876e57149f29568c0f7bc94645c0..e23b2a93585b46a51c31e8fc7c517fc4ce99a23a 100644 (file)
--- a/include/deal.II/distributed/tria.h
+++ b/include/deal.II/distributed/tria.h
@@ -242,6 +242,7 @@ namespace parallel
      * @ingroup distributed
      */
     template <int dim, int spacedim = dim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation
       : public dealii::parallel::DistributedTriangulationBase<dim, spacedim>
     {
@@ -852,6 +853,7 @@ namespace parallel
      * all this class does is throw an exception.
      */
     template <int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
     class Triangulation<1, spacedim>
       : public dealii::parallel::DistributedTriangulationBase<1, spacedim>
     {
@@ -992,6 +994,7 @@ namespace parallel
      * p4est is not available.
      */
     template <int dim, int spacedim = dim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation
       : public dealii::parallel::DistributedTriangulationBase<dim, spacedim>
     {

diff --git a/include/deal.II/distributed/tria_base.h b/include/deal.II/distributed/tria_base.h
index 012de34920c8a5bad55a754d2a43a8419efd175c..d6575b8e4d3ec71f96371966cbb955798f522e4c 100644 (file)
--- a/include/deal.II/distributed/tria_base.h
+++ b/include/deal.II/distributed/tria_base.h
@@ -430,6 +430,7 @@ namespace parallel
    * @endcode
    */
   template <int dim, int spacedim = dim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   class DistributedTriangulationBase
     : public dealii::parallel::TriangulationBase<dim, spacedim>
   {

diff --git a/include/deal.II/grid/grid_tools.h b/include/deal.II/grid/grid_tools.h
index f78f1e2c22d23f2695c7a9e8081e9e40a0e1ed28..c418ac2aad2a7413d8720d2d91d27da189de4aa7 100644 (file)
--- a/include/deal.II/grid/grid_tools.h
+++ b/include/deal.II/grid/grid_tools.h
@@ -77,6 +77,7 @@ namespace parallel
   namespace distributed
   {
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     class Triangulation;
   }
 } // namespace parallel

diff --git a/source/distributed/fully_distributed_tria.cc b/source/distributed/fully_distributed_tria.cc
index 361af19d8bdd58aaea56c1cfa22dd4c0588abe93..5f158e268e4a04a6bd8dcee05742889d45a9009b 100644 (file)
--- a/source/distributed/fully_distributed_tria.cc
+++ b/source/distributed/fully_distributed_tria.cc
@@ -44,6 +44,7 @@ namespace parallel
   namespace fullydistributed
   {
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     Triangulation<dim, spacedim>::Triangulation(
       const MPI_Comm &mpi_communicator)
       : parallel::DistributedTriangulationBase<dim, spacedim>(mpi_communicator)
@@ -60,8 +61,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::create_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::create_triangulation(
       const TriangulationDescription::Description<dim, spacedim>
         &construction_data)
     {
@@ -217,8 +218,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::create_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::create_triangulation(
       const std::vector<Point<spacedim>> &      vertices,
       const std::vector<dealii::CellData<dim>> &cells,
       const SubCellData &                       subcelldata)
@@ -246,8 +247,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::copy_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::copy_triangulation(
       const dealii::Triangulation<dim, spacedim> &other_tria)
     {
       // pointer to the triangulation for which the construction data
@@ -295,8 +296,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::set_partitioner(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::set_partitioner(
       const std::function<void(dealii::Triangulation<dim, spacedim> &,
                                const unsigned int)> &partitioner,
       const TriangulationDescription::Settings &     settings)
@@ -308,8 +309,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::set_partitioner(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::set_partitioner(
       const RepartitioningPolicyTools::Base<dim, spacedim> &partitioner,
       const TriangulationDescription::Settings &            settings)
     {
@@ -320,8 +321,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::repartition()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::repartition()
     {
       // signal that repartitioning has started
       this->signals.pre_distributed_repartition();
@@ -348,8 +349,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::execute_coarsening_and_refinement()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::execute_coarsening_and_refinement()
     {
       Assert(false, ExcNotImplemented());
     }
@@ -357,8 +358,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::prepare_coarsening_and_refinement()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::prepare_coarsening_and_refinement()
     {
       Assert(
         currently_processing_prepare_coarsening_and_refinement_for_internal_usage,
@@ -371,8 +372,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    std::size_t
-    Triangulation<dim, spacedim>::memory_consumption() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    std::size_t Triangulation<dim, spacedim>::memory_consumption() const
     {
       const std::size_t mem =
         this->dealii::parallel::TriangulationBase<dim, spacedim>::
@@ -387,8 +388,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::is_multilevel_hierarchy_constructed() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::is_multilevel_hierarchy_constructed()
+      const
     {
       return (
         settings &
@@ -398,9 +400,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    unsigned int
-    Triangulation<dim, spacedim>::coarse_cell_id_to_coarse_cell_index(
-      const types::coarse_cell_id coarse_cell_id) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    unsigned int Triangulation<dim, spacedim>::
+      coarse_cell_id_to_coarse_cell_index(
+        const types::coarse_cell_id coarse_cell_id) const
     {
       const auto coarse_cell_index = std::lower_bound(
         coarse_cell_id_to_coarse_cell_index_vector.begin(),
@@ -417,9 +420,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     types::coarse_cell_id
-    Triangulation<dim, spacedim>::coarse_cell_index_to_coarse_cell_id(
-      const unsigned int coarse_cell_index) const
+      Triangulation<dim, spacedim>::coarse_cell_index_to_coarse_cell_id(
+        const unsigned int coarse_cell_index) const
     {
       AssertIndexRange(coarse_cell_index,
                        coarse_cell_index_to_coarse_cell_id_vector.size());
@@ -433,8 +437,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::update_cell_relations()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::update_cell_relations()
     {
       // Reorganize memory for local_cell_relations.
       this->local_cell_relations.clear();
@@ -449,8 +453,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::save(const std::string &filename) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::save(const std::string &filename) const
     {
 #ifdef DEAL_II_WITH_MPI
       AssertThrow(this->cell_attached_data.pack_callbacks_variable.size() == 0,
@@ -590,8 +594,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::load(const std::string &filename)
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::load(const std::string &filename)
     {
 #ifdef DEAL_II_WITH_MPI
       Assert(this->n_cells() == 0,
@@ -735,9 +739,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::load(const std::string &filename,
-                                       const bool         autopartition)
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::load(const std::string &filename,
+                                            const bool         autopartition)
     {
       (void)autopartition;
       load(filename);

diff --git a/source/distributed/shared_tria.cc b/source/distributed/shared_tria.cc
index f111aa38fe7c9eeda11b6f9debf7738c27f5f007..e4982a5adb14939d104ceb631dacdbebf202a510 100644 (file)
--- a/source/distributed/shared_tria.cc
+++ b/source/distributed/shared_tria.cc
@@ -39,6 +39,7 @@ namespace parallel
   namespace shared
   {
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     Triangulation<dim, spacedim>::Triangulation(
       const MPI_Comm &mpi_communicator,
       const typename dealii::Triangulation<dim, spacedim>::MeshSmoothing
@@ -73,8 +74,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::is_multilevel_hierarchy_constructed() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::is_multilevel_hierarchy_constructed()
+      const
     {
       return (settings & construct_multigrid_hierarchy);
     }
@@ -82,8 +84,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::partition()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::partition()
     {
 #  ifdef DEBUG
       // Check that all meshes are the same (or at least have the same
@@ -318,8 +320,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::with_artificial_cells() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::with_artificial_cells() const
     {
       return allow_artificial_cells;
     }
@@ -327,8 +329,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    const std::vector<types::subdomain_id> &
-    Triangulation<dim, spacedim>::get_true_subdomain_ids_of_cells() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    const std::vector<types::subdomain_id>
+      &Triangulation<dim, spacedim>::get_true_subdomain_ids_of_cells() const
     {
       return true_subdomain_ids_of_cells;
     }
@@ -336,9 +339,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    const std::vector<types::subdomain_id> &
-    Triangulation<dim, spacedim>::get_true_level_subdomain_ids_of_cells(
-      const unsigned int level) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    const std::vector<types::subdomain_id>
+      &Triangulation<dim, spacedim>::get_true_level_subdomain_ids_of_cells(
+        const unsigned int level) const
     {
       Assert(level < true_level_subdomain_ids_of_cells.size(),
              ExcInternalError());
@@ -351,8 +355,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::execute_coarsening_and_refinement()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::execute_coarsening_and_refinement()
     {
       // make sure that all refinement/coarsening flags are the same on all
       // processes
@@ -422,8 +426,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::create_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::create_triangulation(
       const std::vector<Point<spacedim>> &vertices,
       const std::vector<CellData<dim>> &  cells,
       const SubCellData &                 subcelldata)
@@ -448,8 +452,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::create_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::create_triangulation(
       const TriangulationDescription::Description<dim, spacedim>
         &construction_data)
     {
@@ -461,8 +465,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::copy_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::copy_triangulation(
       const dealii::Triangulation<dim, spacedim> &other_tria)
     {
       Assert(
@@ -487,23 +491,29 @@ namespace parallel
   namespace shared
   {
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::with_artificial_cells() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::with_artificial_cells() const
     {
       Assert(false, ExcNotImplemented());
       return true;
     }
 
+
+
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::is_multilevel_hierarchy_constructed() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::is_multilevel_hierarchy_constructed()
+      const
     {
       return false;
     }
 
+
+
     template <int dim, int spacedim>
-    const std::vector<unsigned int> &
-    Triangulation<dim, spacedim>::get_true_subdomain_ids_of_cells() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    const std::vector<unsigned int>
+      &Triangulation<dim, spacedim>::get_true_subdomain_ids_of_cells() const
     {
       Assert(false, ExcNotImplemented());
       return true_subdomain_ids_of_cells;
@@ -512,9 +522,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    const std::vector<unsigned int> &
-    Triangulation<dim, spacedim>::get_true_level_subdomain_ids_of_cells(
-      const unsigned int) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    const std::vector<unsigned int>
+      &Triangulation<dim, spacedim>::get_true_level_subdomain_ids_of_cells(
+        const unsigned int) const
     {
       Assert(false, ExcNotImplemented());
       return true_level_subdomain_ids_of_cells;

diff --git a/source/distributed/tria.cc b/source/distributed/tria.cc
index 437362557df8998ac5136d104e2f7e1de43d8f09..e43caf145c053092b63734648ab2b45438f2ac00 100644 (file)
--- a/source/distributed/tria.cc
+++ b/source/distributed/tria.cc
@@ -1696,6 +1696,7 @@ namespace parallel
   {
     /*----------------- class Triangulation<dim,spacedim> ---------------\*/
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     Triangulation<dim, spacedim>::Triangulation(
       const MPI_Comm &mpi_communicator,
       const typename dealii::Triangulation<dim, spacedim>::MeshSmoothing
@@ -1724,6 +1725,7 @@ namespace parallel
 
 
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     Triangulation<dim, spacedim>::~Triangulation()
     {
       // virtual functions called in constructors and destructors never use the
@@ -1744,8 +1746,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::create_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::create_triangulation(
       const std::vector<Point<spacedim>> &vertices,
       const std::vector<CellData<dim>> &  cells,
       const SubCellData &                 subcelldata)
@@ -1797,8 +1799,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::create_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::create_triangulation(
       const TriangulationDescription::Description<dim, spacedim>
         &construction_data)
     {
@@ -1810,8 +1812,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::clear()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::clear()
     {
       triangulation_has_content = false;
 
@@ -1846,8 +1848,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::is_multilevel_hierarchy_constructed() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::is_multilevel_hierarchy_constructed()
+      const
     {
       return settings &
              Triangulation<dim, spacedim>::construct_multigrid_hierarchy;
@@ -1856,8 +1859,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::are_vertices_communicated_to_p4est() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::are_vertices_communicated_to_p4est()
+      const
     {
       return settings &
              Triangulation<dim, spacedim>::communicate_vertices_to_p4est;
@@ -1866,8 +1870,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::execute_transfer(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::execute_transfer(
       const typename dealii::internal::p4est::types<dim>::forest
         *parallel_forest,
       const typename dealii::internal::p4est::types<dim>::gloidx
@@ -1961,8 +1965,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::setup_coarse_cell_to_p4est_tree_permutation()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim,
+                       spacedim>::setup_coarse_cell_to_p4est_tree_permutation()
     {
       DynamicSparsityPattern cell_connectivity;
       dealii::GridTools::get_vertex_connectivity_of_cells(*this,
@@ -1978,8 +1983,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::write_mesh_vtk(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::write_mesh_vtk(
       const std::string &file_basename) const
     {
       Assert(parallel_forest != nullptr,
@@ -1997,8 +2002,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::save(const std::string &filename) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::save(const std::string &filename) const
     {
       Assert(
         this->cell_attached_data.n_attached_deserialize == 0,
@@ -2052,8 +2057,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::load(const std::string &filename)
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::load(const std::string &filename)
     {
       Assert(
         this->n_cells() > 0,
@@ -2152,9 +2157,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::load(const std::string &filename,
-                                       const bool         autopartition)
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::load(const std::string &filename,
+                                            const bool         autopartition)
     {
       (void)autopartition;
       load(filename);
@@ -2163,8 +2168,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::load(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::load(
       const typename dealii::internal::p4est::types<dim>::forest *forest)
     {
       Assert(this->n_cells() > 0,
@@ -2216,8 +2221,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    unsigned int
-    Triangulation<dim, spacedim>::get_checksum() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    unsigned int Triangulation<dim, spacedim>::get_checksum() const
     {
       Assert(parallel_forest != nullptr,
              ExcMessage(
@@ -2228,8 +2233,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    const typename dealii::internal::p4est::types<dim>::forest *
-    Triangulation<dim, spacedim>::get_p4est() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    const typename dealii::internal::p4est::types<dim>::forest
+      *Triangulation<dim, spacedim>::get_p4est() const
     {
       Assert(parallel_forest != nullptr,
              ExcMessage("The forest has not been allocated yet."));
@@ -2239,9 +2245,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    typename dealii::internal::p4est::types<dim>::tree *
-    Triangulation<dim, spacedim>::init_tree(
-      const int dealii_coarse_cell_index) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    typename dealii::internal::p4est::types<dim>::tree
+      *Triangulation<dim, spacedim>::init_tree(
+        const int dealii_coarse_cell_index) const
     {
       const unsigned int tree_index =
         coarse_cell_to_p4est_tree_permutation[dealii_coarse_cell_index];
@@ -2733,8 +2740,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    bool
-    Triangulation<dim, spacedim>::prepare_coarsening_and_refinement()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    bool Triangulation<dim, spacedim>::prepare_coarsening_and_refinement()
     {
       bool         mesh_changed = false;
       unsigned int loop_counter = 0;
@@ -2769,8 +2776,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::copy_local_forest_to_triangulation()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::copy_local_forest_to_triangulation()
     {
       // Disable mesh smoothing for recreating the deal.II triangulation,
       // otherwise we might not be able to reproduce the p4est mesh
@@ -3110,8 +3117,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     types::subdomain_id
-    Triangulation<dim, spacedim>::find_point_owner_rank(const Point<dim> &p)
+      Triangulation<dim, spacedim>::find_point_owner_rank(const Point<dim> &p)
     {
       // Call the other function
       std::vector<Point<dim>>          point{p};
@@ -3123,9 +3131,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    std::vector<types::subdomain_id>
-    Triangulation<dim, spacedim>::find_point_owner_rank(
-      const std::vector<Point<dim>> &points)
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    std::vector<types::subdomain_id> Triangulation<dim, spacedim>::
+      find_point_owner_rank(const std::vector<Point<dim>> &points)
     {
 #  ifndef P4EST_SEARCH_LOCAL
       (void)points;
@@ -3223,8 +3231,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::execute_coarsening_and_refinement()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::execute_coarsening_and_refinement()
     {
       // do not allow anisotropic refinement
 #  ifdef DEBUG
@@ -3487,8 +3495,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::repartition()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::repartition()
     {
 #  ifdef DEBUG
       for (const auto &cell : this->active_cell_iterators())
@@ -3596,9 +3604,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    const std::vector<types::global_dof_index> &
-    Triangulation<dim, spacedim>::get_p4est_tree_to_coarse_cell_permutation()
-      const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    const std::vector<types::global_dof_index>
+      &Triangulation<dim, spacedim>::get_p4est_tree_to_coarse_cell_permutation()
+        const
     {
       return p4est_tree_to_coarse_cell_permutation;
     }
@@ -3606,9 +3615,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    const std::vector<types::global_dof_index> &
-    Triangulation<dim, spacedim>::get_coarse_cell_to_p4est_tree_permutation()
-      const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    const std::vector<types::global_dof_index>
+      &Triangulation<dim, spacedim>::get_coarse_cell_to_p4est_tree_permutation()
+        const
     {
       return coarse_cell_to_p4est_tree_permutation;
     }
@@ -3616,9 +3626,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    std::vector<bool>
-    Triangulation<dim, spacedim>::mark_locally_active_vertices_on_level(
-      const int level) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    std::vector<bool> Triangulation<dim, spacedim>::
+      mark_locally_active_vertices_on_level(const int level) const
     {
       Assert(dim > 1, ExcNotImplemented());
 
@@ -3684,9 +3694,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    unsigned int
-    Triangulation<dim, spacedim>::coarse_cell_id_to_coarse_cell_index(
-      const types::coarse_cell_id coarse_cell_id) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    unsigned int Triangulation<dim, spacedim>::
+      coarse_cell_id_to_coarse_cell_index(
+        const types::coarse_cell_id coarse_cell_id) const
     {
       return p4est_tree_to_coarse_cell_permutation[coarse_cell_id];
     }
@@ -3694,9 +3705,10 @@ namespace parallel
 
 
     template <int dim, int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
     types::coarse_cell_id
-    Triangulation<dim, spacedim>::coarse_cell_index_to_coarse_cell_id(
-      const unsigned int coarse_cell_index) const
+      Triangulation<dim, spacedim>::coarse_cell_index_to_coarse_cell_id(
+        const unsigned int coarse_cell_index) const
     {
       return coarse_cell_to_p4est_tree_permutation[coarse_cell_index];
     }
@@ -3704,8 +3716,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::add_periodicity(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::add_periodicity(
       const std::vector<dealii::GridTools::PeriodicFacePair<cell_iterator>>
         &periodicity_vector)
     {
@@ -3867,8 +3879,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    std::size_t
-    Triangulation<dim, spacedim>::memory_consumption() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    std::size_t Triangulation<dim, spacedim>::memory_consumption() const
     {
       std::size_t mem =
         this->dealii::parallel::TriangulationBase<dim, spacedim>::
@@ -3895,8 +3907,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    std::size_t
-    Triangulation<dim, spacedim>::memory_consumption_p4est() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    std::size_t Triangulation<dim, spacedim>::memory_consumption_p4est() const
     {
       return dealii::internal::p4est::functions<dim>::forest_memory_used(
                parallel_forest) +
@@ -3907,8 +3919,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::copy_triangulation(
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::copy_triangulation(
       const dealii::Triangulation<dim, spacedim> &other_tria)
     {
       Assert(
@@ -3991,8 +4003,8 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    void
-    Triangulation<dim, spacedim>::update_cell_relations()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    void Triangulation<dim, spacedim>::update_cell_relations()
     {
       // reorganize memory for local_cell_relations
       this->local_cell_relations.resize(parallel_forest->local_num_quadrants);
@@ -4024,8 +4036,9 @@ namespace parallel
 
 
     template <int dim, int spacedim>
-    std::vector<unsigned int>
-    Triangulation<dim, spacedim>::get_cell_weights() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+    std::vector<unsigned int> Triangulation<dim, spacedim>::get_cell_weights()
+      const
     {
       // check if local_cell_relations have been previously gathered
       // correctly
@@ -4058,6 +4071,7 @@ namespace parallel
 
 
     template <int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
     Triangulation<1, spacedim>::Triangulation(
       const MPI_Comm &mpi_communicator,
       const typename dealii::Triangulation<1, spacedim>::MeshSmoothing
@@ -4073,6 +4087,7 @@ namespace parallel
 
 
     template <int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
     Triangulation<1, spacedim>::~Triangulation()
     {
       AssertNothrow(false, ExcNotImplemented());
@@ -4081,9 +4096,10 @@ namespace parallel
 
 
     template <int spacedim>
-    const std::vector<types::global_dof_index> &
-    Triangulation<1, spacedim>::get_p4est_tree_to_coarse_cell_permutation()
-      const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    const std::vector<types::global_dof_index>
+      &Triangulation<1, spacedim>::get_p4est_tree_to_coarse_cell_permutation()
+        const
     {
       static std::vector<types::global_dof_index> a;
       return a;
@@ -4092,9 +4108,11 @@ namespace parallel
 
 
     template <int spacedim>
-    std::map<unsigned int, std::set<dealii::types::subdomain_id>>
-    Triangulation<1, spacedim>::compute_level_vertices_with_ghost_neighbors(
-      const unsigned int /*level*/) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    std::map<unsigned int,
+             std::set<dealii::types::subdomain_id>> Triangulation<1, spacedim>::
+      compute_level_vertices_with_ghost_neighbors(
+        const unsigned int /*level*/) const
     {
       Assert(false, ExcNotImplemented());
 
@@ -4104,9 +4122,9 @@ namespace parallel
 
 
     template <int spacedim>
-    std::vector<bool>
-    Triangulation<1, spacedim>::mark_locally_active_vertices_on_level(
-      const unsigned int) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    std::vector<bool> Triangulation<1, spacedim>::
+      mark_locally_active_vertices_on_level(const unsigned int) const
     {
       Assert(false, ExcNotImplemented());
       return std::vector<bool>();
@@ -4115,9 +4133,9 @@ namespace parallel
 
 
     template <int spacedim>
-    unsigned int
-    Triangulation<1, spacedim>::coarse_cell_id_to_coarse_cell_index(
-      const types::coarse_cell_id) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    unsigned int Triangulation<1, spacedim>::
+      coarse_cell_id_to_coarse_cell_index(const types::coarse_cell_id) const
     {
       Assert(false, ExcNotImplemented());
       return 0;
@@ -4126,9 +4144,10 @@ namespace parallel
 
 
     template <int spacedim>
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
     types::coarse_cell_id
-    Triangulation<1, spacedim>::coarse_cell_index_to_coarse_cell_id(
-      const unsigned int) const
+      Triangulation<1, spacedim>::coarse_cell_index_to_coarse_cell_id(
+        const unsigned int) const
     {
       Assert(false, ExcNotImplemented());
       return 0;
@@ -4137,8 +4156,8 @@ namespace parallel
 
 
     template <int spacedim>
-    void
-    Triangulation<1, spacedim>::load(const std::string &)
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    void Triangulation<1, spacedim>::load(const std::string &)
     {
       Assert(false, ExcNotImplemented());
     }
@@ -4146,8 +4165,8 @@ namespace parallel
 
 
     template <int spacedim>
-    void
-    Triangulation<1, spacedim>::load(const std::string &, const bool)
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    void Triangulation<1, spacedim>::load(const std::string &, const bool)
     {
       Assert(false, ExcNotImplemented());
     }
@@ -4155,8 +4174,8 @@ namespace parallel
 
 
     template <int spacedim>
-    void
-    Triangulation<1, spacedim>::save(const std::string &) const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    void Triangulation<1, spacedim>::save(const std::string &) const
     {
       Assert(false, ExcNotImplemented());
     }
@@ -4164,8 +4183,8 @@ namespace parallel
 
 
     template <int spacedim>
-    bool
-    Triangulation<1, spacedim>::is_multilevel_hierarchy_constructed() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    bool Triangulation<1, spacedim>::is_multilevel_hierarchy_constructed() const
     {
       Assert(false, ExcNotImplemented());
       return false;
@@ -4174,8 +4193,8 @@ namespace parallel
 
 
     template <int spacedim>
-    bool
-    Triangulation<1, spacedim>::are_vertices_communicated_to_p4est() const
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    bool Triangulation<1, spacedim>::are_vertices_communicated_to_p4est() const
     {
       Assert(false, ExcNotImplemented());
       return false;
@@ -4184,8 +4203,8 @@ namespace parallel
 
 
     template <int spacedim>
-    void
-    Triangulation<1, spacedim>::update_cell_relations()
+    DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<1, spacedim>))
+    void Triangulation<1, spacedim>::update_cell_relations()
     {
       Assert(false, ExcNotImplemented());
     }

diff --git a/source/distributed/tria_base.cc b/source/distributed/tria_base.cc
index 1b69fa841040ffaaae0b494a34290e29b3e7c21c..aed0cc2e109f5bb04751e79f4bae1860090a946f 100644 (file)
--- a/source/distributed/tria_base.cc
+++ b/source/distributed/tria_base.cc
@@ -44,6 +44,7 @@ DEAL_II_NAMESPACE_OPEN
 namespace parallel
 {
   template <int dim, int spacedim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   TriangulationBase<dim, spacedim>::TriangulationBase(
     const MPI_Comm &mpi_communicator,
     const typename dealii::Triangulation<dim, spacedim>::MeshSmoothing
@@ -63,8 +64,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  TriangulationBase<dim, spacedim>::copy_triangulation(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void TriangulationBase<dim, spacedim>::copy_triangulation(
     const dealii::Triangulation<dim, spacedim> &other_tria)
   {
 #ifndef DEAL_II_WITH_MPI
@@ -88,8 +89,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  std::size_t
-  TriangulationBase<dim, spacedim>::memory_consumption() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  std::size_t TriangulationBase<dim, spacedim>::memory_consumption() const
   {
     std::size_t mem =
       this->dealii::Triangulation<dim, spacedim>::memory_consumption() +
@@ -101,7 +102,10 @@ namespace parallel
     return mem;
   }
 
+
+
   template <int dim, int spacedim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   TriangulationBase<dim, spacedim>::~TriangulationBase()
   {
     // release unused vector memory because the vector layout is going to look
@@ -110,45 +114,60 @@ namespace parallel
       release_all_unused_memory();
   }
 
+
+
   template <int dim, int spacedim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   TriangulationBase<dim, spacedim>::NumberCache::NumberCache()
     : n_locally_owned_active_cells(0)
     , number_of_global_coarse_cells(0)
     , n_global_levels(0)
   {}
 
+
+
   template <int dim, int spacedim>
-  unsigned int
-  TriangulationBase<dim, spacedim>::n_locally_owned_active_cells() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  unsigned int TriangulationBase<dim, spacedim>::n_locally_owned_active_cells()
+    const
   {
     return number_cache.n_locally_owned_active_cells;
   }
 
+
+
   template <int dim, int spacedim>
-  unsigned int
-  TriangulationBase<dim, spacedim>::n_global_levels() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  unsigned int TriangulationBase<dim, spacedim>::n_global_levels() const
   {
     return number_cache.n_global_levels;
   }
 
+
+
   template <int dim, int spacedim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   types::global_cell_index
-  TriangulationBase<dim, spacedim>::n_global_active_cells() const
+    TriangulationBase<dim, spacedim>::n_global_active_cells() const
   {
     return number_cache.n_global_active_cells;
   }
 
+
+
   template <int dim, int spacedim>
-  MPI_Comm
-  TriangulationBase<dim, spacedim>::get_communicator() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  MPI_Comm TriangulationBase<dim, spacedim>::get_communicator() const
   {
     return mpi_communicator;
   }
 
+
+
 #ifdef DEAL_II_WITH_MPI
   template <int dim, int spacedim>
-  void
-  TriangulationBase<dim, spacedim>::update_number_cache()
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void TriangulationBase<dim, spacedim>::update_number_cache()
   {
     number_cache.ghost_owners.clear();
     number_cache.level_ghost_owners.clear();
@@ -283,8 +302,8 @@ namespace parallel
 #else
 
   template <int dim, int spacedim>
-  void
-  TriangulationBase<dim, spacedim>::update_number_cache()
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void TriangulationBase<dim, spacedim>::update_number_cache()
   {
     Assert(false, ExcNeedsMPI());
   }
@@ -292,8 +311,8 @@ namespace parallel
 #endif
 
   template <int dim, int spacedim>
-  void
-  TriangulationBase<dim, spacedim>::update_reference_cells()
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void TriangulationBase<dim, spacedim>::update_reference_cells()
   {
     // run algorithm for locally-owned cells
     dealii::Triangulation<dim, spacedim>::update_reference_cells();
@@ -321,8 +340,9 @@ namespace parallel
 
 
   template <int dim, int spacedim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   types::subdomain_id
-  TriangulationBase<dim, spacedim>::locally_owned_subdomain() const
+    TriangulationBase<dim, spacedim>::locally_owned_subdomain() const
   {
     return my_subdomain;
   }
@@ -330,8 +350,9 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  const std::set<types::subdomain_id> &
-  TriangulationBase<dim, spacedim>::ghost_owners() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  const std::set<types::subdomain_id>
+    &TriangulationBase<dim, spacedim>::ghost_owners() const
   {
     return number_cache.ghost_owners;
   }
@@ -339,8 +360,9 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  const std::set<types::subdomain_id> &
-  TriangulationBase<dim, spacedim>::level_ghost_owners() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  const std::set<types::subdomain_id>
+    &TriangulationBase<dim, spacedim>::level_ghost_owners() const
   {
     return number_cache.level_ghost_owners;
   }
@@ -348,8 +370,9 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  std::vector<types::boundary_id>
-  TriangulationBase<dim, spacedim>::get_boundary_ids() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  std::vector<types::boundary_id> TriangulationBase<dim, spacedim>::
+    get_boundary_ids() const
   {
     return Utilities::MPI::compute_set_union(
       dealii::Triangulation<dim, spacedim>::get_boundary_ids(),
@@ -359,8 +382,9 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  std::vector<types::manifold_id>
-  TriangulationBase<dim, spacedim>::get_manifold_ids() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  std::vector<types::manifold_id> TriangulationBase<dim, spacedim>::
+    get_manifold_ids() const
   {
     return Utilities::MPI::compute_set_union(
       dealii::Triangulation<dim, spacedim>::get_manifold_ids(),
@@ -370,8 +394,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  TriangulationBase<dim, spacedim>::reset_global_cell_indices()
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void TriangulationBase<dim, spacedim>::reset_global_cell_indices()
   {
 #ifndef DEAL_II_WITH_MPI
     Assert(false, ExcNeedsMPI());
@@ -554,8 +578,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  TriangulationBase<dim, spacedim>::communicate_locally_moved_vertices(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void TriangulationBase<dim, spacedim>::communicate_locally_moved_vertices(
     const std::vector<bool> &vertex_locally_moved)
   {
     AssertDimension(vertex_locally_moved.size(), this->n_vertices());
@@ -609,8 +633,10 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  const std::weak_ptr<const Utilities::MPI::Partitioner>
-  TriangulationBase<dim, spacedim>::global_active_cell_index_partitioner() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  const std::weak_ptr<const Utilities::MPI::Partitioner> TriangulationBase<
+    dim,
+    spacedim>::global_active_cell_index_partitioner() const
   {
     return number_cache.active_cell_index_partitioner;
   }
@@ -618,9 +644,11 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  const std::weak_ptr<const Utilities::MPI::Partitioner>
-  TriangulationBase<dim, spacedim>::global_level_cell_index_partitioner(
-    const unsigned int level) const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  const std::weak_ptr<const Utilities::MPI::Partitioner> TriangulationBase<
+    dim,
+    spacedim>::global_level_cell_index_partitioner(const unsigned int level)
+    const
   {
     Assert(this->is_multilevel_hierarchy_constructed(), ExcNotImplemented());
     AssertIndexRange(level, this->n_global_levels());
@@ -631,8 +659,9 @@ namespace parallel
 
 
   template <int dim, int spacedim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   types::coarse_cell_id
-  TriangulationBase<dim, spacedim>::n_global_coarse_cells() const
+    TriangulationBase<dim, spacedim>::n_global_coarse_cells() const
   {
     return number_cache.number_of_global_coarse_cells;
   }
@@ -640,6 +669,7 @@ namespace parallel
 
 
   template <int dim, int spacedim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   DistributedTriangulationBase<dim, spacedim>::DistributedTriangulationBase(
     const MPI_Comm &mpi_communicator,
     const typename dealii::Triangulation<dim, spacedim>::MeshSmoothing
@@ -656,8 +686,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::clear()
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::clear()
   {
     cell_attached_data = {0, 0, {}, {}};
     data_transfer.clear();
@@ -668,8 +698,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::save_attached_data(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::save_attached_data(
     const unsigned int global_first_cell,
     const unsigned int global_num_cells,
     const std::string &filename) const
@@ -705,8 +735,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  bool
-  DistributedTriangulationBase<dim, spacedim>::has_hanging_nodes() const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  bool DistributedTriangulationBase<dim, spacedim>::has_hanging_nodes() const
   {
     if (this->n_global_levels() <= 1)
       return false; // can not have hanging nodes without refined cells
@@ -732,8 +762,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::load_attached_data(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::load_attached_data(
     const unsigned int global_first_cell,
     const unsigned int global_num_cells,
     const unsigned int local_num_cells,
@@ -769,11 +799,12 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  unsigned int
-  DistributedTriangulationBase<dim, spacedim>::register_data_attach(
-    const std::function<std::vector<char>(const cell_iterator &,
-                                          const CellStatus)> &pack_callback,
-    const bool returns_variable_size_data)
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  unsigned int DistributedTriangulationBase<dim, spacedim>::
+    register_data_attach(
+      const std::function<std::vector<char>(const cell_iterator &,
+                                            const CellStatus)> &pack_callback,
+      const bool returns_variable_size_data)
   {
     unsigned int handle = numbers::invalid_unsigned_int;
 
@@ -799,8 +830,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::notify_ready_to_unpack(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::notify_ready_to_unpack(
     const unsigned int handle,
     const std::function<
       void(const cell_iterator &,
@@ -844,6 +875,7 @@ namespace parallel
 
 
   template <int dim, int spacedim>
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
   DistributedTriangulationBase<dim, spacedim>::DataTransfer::DataTransfer(
     const MPI_Comm &mpi_communicator)
     : variable_size_data_stored(false)
@@ -853,8 +885,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::DataTransfer::pack_data(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::DataTransfer::pack_data(
     const std::vector<cell_relation_t> &cell_relations,
     const std::vector<typename CellAttachedData::pack_callback_t>
       &pack_callbacks_fixed,
@@ -1189,9 +1221,9 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::DataTransfer::unpack_cell_status(
-    std::vector<cell_relation_t> &cell_relations) const
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::DataTransfer::
+    unpack_cell_status(std::vector<cell_relation_t> &cell_relations) const
   {
     Assert(sizes_fixed_cumulative.size() > 0,
            ExcMessage("No data has been packed!"));
@@ -1225,8 +1257,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::DataTransfer::unpack_data(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::DataTransfer::unpack_data(
     const std::vector<cell_relation_t> &cell_relations,
     const unsigned int                  handle,
     const std::function<
@@ -1396,8 +1428,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::DataTransfer::save(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::DataTransfer::save(
     const unsigned int global_first_cell,
     const unsigned int global_num_cells,
     const std::string &filename) const
@@ -1577,8 +1609,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::DataTransfer::load(
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::DataTransfer::load(
     const unsigned int global_first_cell,
     const unsigned int global_num_cells,
     const unsigned int local_num_cells,
@@ -1742,8 +1774,8 @@ namespace parallel
 
 
   template <int dim, int spacedim>
-  void
-  DistributedTriangulationBase<dim, spacedim>::DataTransfer::clear()
+  DEAL_II_CXX20_REQUIRES((concepts::is_valid_dim_spacedim<dim, spacedim>))
+  void DistributedTriangulationBase<dim, spacedim>::DataTransfer::clear()
   {
     variable_size_data_stored = false;