From 6f547af8ed9002cd492b88b90c1d63b6d319bef8 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Wed, 3 Feb 2021 09:14:31 -0700
Subject: [PATCH] Move n_vertices_to_type() into ReferenceCell::Type.

---
 include/deal.II/grid/connectivity.h           | 13 ++++++------
 include/deal.II/grid/reference_cell.h         | 20 ++++++++++++-------
 .../deal.II/grid/tria_accessor.templates.h    |  2 +-
 source/grid/grid_in.cc                        |  3 ++-
 4 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/include/deal.II/grid/connectivity.h b/include/deal.II/grid/connectivity.h
index d049fa5f09..9cdc7d9e58 100644
--- a/include/deal.II/grid/connectivity.h
+++ b/include/deal.II/grid/connectivity.h
@@ -1490,19 +1490,20 @@ namespace internal
       // loop over cells and create CRS
       for (const auto &cell : cells)
         {
-          const ReferenceCell::Type cell_type =
-            ReferenceCell::n_vertices_to_type(dim, cell.vertices.size());
+          const ReferenceCell::Type reference_cell_type =
+            ReferenceCell::Type::n_vertices_to_type(dim, cell.vertices.size());
 
-          Assert(cell_type != ReferenceCell::Type::Invalid,
+          Assert(reference_cell_type != ReferenceCell::Type::Invalid,
                  ExcNotImplemented());
-          AssertIndexRange(static_cast<types::geometric_entity_type>(cell_type),
+          AssertIndexRange(static_cast<types::geometric_entity_type>(
+                             reference_cell_type),
                            cell_types_impl.size());
           Assert(cell_types_impl[static_cast<types::geometric_entity_type>(
-                                   cell_type)]
+                                   reference_cell_type)]
                      .get() != nullptr,
                  ExcNotImplemented());
 
-          cell_types_indices.push_back(cell_type);
+          cell_types_indices.push_back(reference_cell_type);
 
           // create CRS of vertices (to remove template argument dim)
           for (const auto &vertex : cell.vertices)
diff --git a/include/deal.II/grid/reference_cell.h b/include/deal.II/grid/reference_cell.h
index 3950b01662..61360d906f 100644
--- a/include/deal.II/grid/reference_cell.h
+++ b/include/deal.II/grid/reference_cell.h
@@ -93,7 +93,6 @@ namespace ReferenceCell
     static constexpr const Type &
     get_simplex();
 
-
     /**
      * Return the correct hypercube reference cell type for the given dimension
      * `dim`. Depending on the template argument `dim`, this function returns a
@@ -103,6 +102,15 @@ namespace ReferenceCell
     static constexpr const Type &
     get_hypercube();
 
+    /**
+     * Return the correct ReferenceCell::Type for a given structural dimension
+     * and number of vertices. For example, if `dim==2` and `n_vertices==4`,
+     * this function will return `Quad`. But if `dim==3` and `n_vertices==4`, it
+     * will return `Tri`.
+     */
+    static Type
+    n_vertices_to_type(const int dim, const unsigned int n_vertices);
+
     /**
      * Default constructor. Initialize this object as an invalid object.
      */
@@ -482,17 +490,15 @@ namespace ReferenceCell
       }
   }
 
-  /**
-   * Retrieve the correct ReferenceCell::Type for a given structural dimension
-   * and number of vertices.
-   */
+
+
   inline Type
-  n_vertices_to_type(const int dim, const unsigned int n_vertices)
+  Type::n_vertices_to_type(const int dim, const unsigned int n_vertices)
   {
     AssertIndexRange(dim, 4);
     AssertIndexRange(n_vertices, 9);
-    const auto X = Type::Invalid;
 
+    const auto X = Type::Invalid;
     static const std::array<std::array<ReferenceCell::Type, 9>,
                             4>
       table = {
diff --git a/include/deal.II/grid/tria_accessor.templates.h b/include/deal.II/grid/tria_accessor.templates.h
index 9a4646649d..7e99c609fb 100644
--- a/include/deal.II/grid/tria_accessor.templates.h
+++ b/include/deal.II/grid/tria_accessor.templates.h
@@ -55,7 +55,7 @@ namespace internal
         vertices)
     {
       const ReferenceCell::Type reference_cell_type =
-        ReferenceCell::n_vertices_to_type(dim, vertices.size());
+        ReferenceCell::Type::n_vertices_to_type(dim, vertices.size());
 
       if (reference_cell_type == ReferenceCell::Type::Line)
         // Return the distance between the two vertices
diff --git a/source/grid/grid_in.cc b/source/grid/grid_in.cc
index 5da5ea53b8..4328f617ac 100644
--- a/source/grid/grid_in.cc
+++ b/source/grid/grid_in.cc
@@ -3193,7 +3193,8 @@ namespace
             const unsigned int   local_face_n = face_id % max_faces_per_cell;
             const CellData<dim> &cell = cells[face_id / max_faces_per_cell];
             const ReferenceCell::Type cell_type =
-              ReferenceCell::n_vertices_to_type(dim, cell.vertices.size());
+              ReferenceCell::Type::n_vertices_to_type(dim,
+                                                      cell.vertices.size());
             const ReferenceCell::internal::Info::Base &info =
               ReferenceCell::internal::Info::get_cell(cell_type);
             const unsigned int deal_face_n =
-- 
2.39.5