From b3b6f6fedbba91e988e39e3773f6421b6c9b18d2 Mon Sep 17 00:00:00 2001
From: Shikhar Kumar <shikhark@mit.edu>
Date: Fri, 12 Feb 2021 19:18:57 -0500
Subject: [PATCH] Use dynamic_cast to get type of sub-class instead of storing
 type as variable

---
 include/openmc/mesh.h | 10 ----------
 src/mesh.cpp          | 45 ++++++++++++++++++++++++++++++-------------
 2 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/include/openmc/mesh.h b/include/openmc/mesh.h
index b2e35819c6..b2d919d30a 100644
--- a/include/openmc/mesh.h
+++ b/include/openmc/mesh.h
@@ -46,8 +46,6 @@ public:
   Mesh(pugi::xml_node node);
   virtual ~Mesh() = default;
 
-  virtual std::string type() const = 0;
-
   // Methods
 
   //! Determine which bins were crossed by a particle
@@ -196,8 +194,6 @@ public:
 
   // Overriden methods
 
-  std::string type() const override {return "regular";}
-
   void surface_bins_crossed(const Particle& p, std::vector<int>& bins)
   const override;
 
@@ -228,8 +224,6 @@ public:
 
   // Overriden methods
 
-  std::string type() const override {return "rectilinear";}
-
   void surface_bins_crossed(const Particle& p, std::vector<int>& bins)
   const override;
 
@@ -256,8 +250,6 @@ public:
   UnstructuredMesh(pugi::xml_node);
   ~UnstructuredMesh() = default;
 
-  std::string type() const override {return "unstructured";}
-
   void bins_crossed(const Particle& p,
                     std::vector<int>& bins,
                     std::vector<double>& lengths) const override;
@@ -430,8 +422,6 @@ void read_meshes(pugi::xml_node root);
 //! \param[in] group HDF5 group
 void meshes_to_hdf5(hid_t group);
 
-RegularMesh* get_regular_mesh(int32_t index);
-
 void free_memory_mesh();
 
 } // namespace openmc
diff --git a/src/mesh.cpp b/src/mesh.cpp
index 576ae3e772..a4b93e9af4 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -865,7 +865,7 @@ void RegularMesh::to_hdf5(hid_t group) const
 {
   hid_t mesh_group = create_group(group, "mesh " + std::to_string(id_));
 
-  write_dataset(mesh_group, "type", type());
+  write_dataset(mesh_group, "type", "regular");
   write_dataset(mesh_group, "dimension", shape_);
   write_dataset(mesh_group, "lower_left", lower_left_);
   write_dataset(mesh_group, "upper_right", upper_right_);
@@ -1122,7 +1122,7 @@ void RectilinearMesh::to_hdf5(hid_t group) const
 {
   hid_t mesh_group = create_group(group, "mesh " + std::to_string(id_));
 
-  write_dataset(mesh_group, "type", type());
+  write_dataset(mesh_group, "type", "rectilinear");
   write_dataset(mesh_group, "x_grid", grid_[0]);
   write_dataset(mesh_group, "y_grid", grid_[1]);
   write_dataset(mesh_group, "z_grid", grid_[2]);
@@ -1148,10 +1148,23 @@ int
 check_mesh_type(int32_t index, const std::string& mesh_compare_type)
 {
   if (int err = check_mesh(index)) return err;
-  StructuredMesh* mesh = dynamic_cast<StructuredMesh*>(model::meshes[index].get());
-  auto mesh_type = mesh->type();
-  if (mesh_compare_type != mesh_type) {
-    set_errmsg("This function is only valid for " + mesh_type + " meshes.");
+
+  if (mesh_compare_type == "regular") {
+    RegularMesh* mesh = dynamic_cast<RegularMesh*>(model::meshes[index].get());
+    if (!mesh) {
+      set_errmsg("This function is only valid for regular meshes.");
+      return OPENMC_E_INVALID_TYPE;
+    }
+  }
+  else if (mesh_compare_type == "rectilinear") {
+    RectilinearMesh* mesh = dynamic_cast<RectilinearMesh*>(model::meshes[index].get());
+    if (!mesh) {
+      set_errmsg("This function is only valid for rectilinear meshes.");
+      return OPENMC_E_INVALID_TYPE;
+    }
+  }
+  else {
+    set_errmsg("Mesh type " + mesh_compare_type + " is not supported.");
     return OPENMC_E_INVALID_TYPE;
   }
   return 0;
@@ -1167,21 +1180,27 @@ openmc_mesh_get_type(int32_t index, char* type)
 {
   if (int err = check_mesh(index)) return err;
 
-  StructuredMesh* mesh = dynamic_cast<StructuredMesh*>(model::meshes[index].get());
-  std::strcpy(type, mesh->type().c_str());
+  RegularMesh* mesh = dynamic_cast<RegularMesh*>(model::meshes[index].get());
+  if (mesh) {
+    std::strcpy(type, "regular");
+  }
+  else {
+    RectilinearMesh* mesh = dynamic_cast<RectilinearMesh*>(model::meshes[index].get());
+    if (mesh) {
+      std::strcpy(type, "rectilinear");
+    }
+  }
   return 0;
 }
 
-RegularMesh* get_regular_mesh(int32_t index) {
-  return dynamic_cast<RegularMesh*>(model::meshes[index].get());
-}
-
 //! Extend the meshes array by n elements
 extern "C" int
 openmc_extend_meshes(int32_t n, const char* type, int32_t* index_start,
                      int32_t* index_end)
 {
   if (index_start) *index_start = model::meshes.size();
+  std::string mesh_type;
+
   for (int i = 0; i < n; ++i) {
     if (std::strcmp(type, "regular") == 0)
     {
@@ -1670,7 +1689,7 @@ UnstructuredMesh::to_hdf5(hid_t group) const
 {
     hid_t mesh_group = create_group(group, fmt::format("mesh {}", id_));
 
-    write_dataset(mesh_group, "type", type());
+    write_dataset(mesh_group, "type", "unstructured");
     write_dataset(mesh_group, "filename", filename_);
 
     // write volume and centroid of each tet