std::set_... -> std::ranges::set_... (#3298)

cpp/dolfinx/fem/DirichletBC.cpp

@@ -266,8 +266,7 @@ std::vector<std::int32_t> fem::locate_dofs_topological(
       std::span src = map->src();
       std::span dest = map->dest();
       std::vector<int> ranks;
-      std::set_union(src.begin(), src.end(), dest.begin(), dest.end(),
-                     std::back_inserter(ranks));
+      std::ranges::set_union(src, dest, std::back_inserter(ranks));
       ranks.erase(std::unique(ranks.begin(), ranks.end()), ranks.end());
       MPI_Dist_graph_create_adjacent(
           map->comm(), ranks.size(), ranks.data(), MPI_UNWEIGHTED, ranks.size(),
@@ -385,8 +384,7 @@ std::array<std::vector<std::int32_t>, 2> fem::locate_dofs_topological(
       std::span src = map0->src();
       std::span dest = map0->dest();
       std::vector<int> ranks;
-      std::set_union(src.begin(), src.end(), dest.begin(), dest.end(),
-                     std::back_inserter(ranks));
+      std::ranges::set_union(src, dest, std::back_inserter(ranks));
       ranks.erase(std::unique(ranks.begin(), ranks.end()), ranks.end());
       MPI_Dist_graph_create_adjacent(map0->comm(), ranks.size(), ranks.data(),
                                      MPI_UNWEIGHTED, ranks.size(), ranks.data(),

cpp/dolfinx/fem/utils.cpp

@@ -173,8 +173,8 @@ std::vector<std::int32_t> fem::compute_integration_domains(
       // Create list of tagged boundary facets
       const std::vector bfacets = mesh::exterior_facet_indices(topology);
       std::vector<std::int32_t> facets;
-      std::set_intersection(entities.begin(), entities.end(), bfacets.begin(),
-                            bfacets.end(), std::back_inserter(facets));
+      std::ranges::set_intersection(entities, bfacets,
+                                    std::back_inserter(facets));
       for (auto f : facets)
       {
         // Get the facet as a pair of (cell, local facet)

cpp/dolfinx/mesh/Topology.cpp

@@ -324,24 +324,21 @@ std::array<std::vector<std::int64_t>, 2> vertex_ownership_groups(
   // Build difference 1: Vertices attached only to owned cells, and
   // therefore owned by this rank
   std::vector<std::int64_t> owned_vertices;
-  std::set_difference(local_vertex_set.begin(), local_vertex_set.end(),
-                      boundary_vertices.begin(), boundary_vertices.end(),
-                      std::back_inserter(owned_vertices));
+  std::ranges::set_difference(local_vertex_set, boundary_vertices,
+                              std::back_inserter(owned_vertices));
 
   // Build difference 2: Vertices attached only to ghost cells, and
   // therefore not owned by this rank
   std::vector<std::int64_t> unowned_vertices;
-  std::set_difference(ghost_vertex_set.begin(), ghost_vertex_set.end(),
-                      local_vertex_set.begin(), local_vertex_set.end(),
-                      std::back_inserter(unowned_vertices));
+  std::ranges::set_difference(ghost_vertex_set, local_vertex_set,
+                              std::back_inserter(unowned_vertices));
 
   // TODO Check this in debug mode only?
   // Sanity check
   // No vertices in unowned should also be in boundary...
   std::vector<std::int64_t> unowned_vertices_in_error;
-  std::set_intersection(unowned_vertices.begin(), unowned_vertices.end(),
-                        boundary_vertices.begin(), boundary_vertices.end(),
-                        std::back_inserter(unowned_vertices_in_error));
+  std::ranges::set_intersection(unowned_vertices, boundary_vertices,
+                                std::back_inserter(unowned_vertices_in_error));
 
   if (!unowned_vertices_in_error.empty())
   {

cpp/dolfinx/mesh/utils.cpp

@@ -75,12 +75,9 @@ std::vector<std::int32_t> mesh::exterior_facet_indices(const Topology& topology)
   }
 
   // Remove facets on internal inter-process boundary
-  const std::vector<std::int32_t>& interprocess_facets
-      = topology.interprocess_facets();
   std::vector<std::int32_t> ext_facets;
-  std::set_difference(facets.begin(), facets.end(), interprocess_facets.begin(),
-                      interprocess_facets.end(),
-                      std::back_inserter(ext_facets));
+  std::ranges::set_difference(facets, topology.interprocess_facets(),
+                              std::back_inserter(ext_facets));
   return ext_facets;
 }
 //------------------------------------------------------------------------------

cpp/dolfinx/refinement/plaza.h

@@ -85,21 +85,21 @@ auto compute_parent_facets(std::span<const std::int32_t> simplex_set)
         {
           for (int j = 0; j < tdim; ++j)
             cf[j] = simplex_set[cc * 3 + facet_table_2d[fci][j]];
+
           std::ranges::sort(cf);
-          auto it = std::set_intersection(facet_table_2d[fpi].begin(),
-                                          facet_table_2d[fpi].end(), cf.begin(),
-                                          cf.end(), set_output.begin());
-          num_common_vertices = std::distance(set_output.begin(), it);
+          auto [last1, last2, it_last] = std::ranges::set_intersection(
+              facet_table_2d[fpi], cf, set_output.begin());
+          num_common_vertices = std::distance(set_output.begin(), it_last);
         }
         else
         {
           for (int j = 0; j < tdim; ++j)
             cf[j] = simplex_set[cc * 4 + facet_table_3d[fci][j]];
+
           std::ranges::sort(cf);
-          auto it = std::set_intersection(facet_table_3d[fpi].begin(),
-                                          facet_table_3d[fpi].end(), cf.begin(),
-                                          cf.end(), set_output.begin());
-          num_common_vertices = std::distance(set_output.begin(), it);
+          auto [last1, last2, it_last] = std::ranges::set_intersection(
+              facet_table_3d[fpi], cf, set_output.begin());
+          num_common_vertices = std::distance(set_output.begin(), it_last);
         }
 
         if (num_common_vertices == tdim)