Rewrite BoundaryHistory to support substeps

.clang-tidy

@@ -86,6 +86,10 @@ Checks: '*,
 CheckOptions:
   - key: performance-move-const-arg.CheckTriviallyCopyableMove
     value: false
+  - key: cppcoreguidelines-special-member-functions.AllowSoleDefaultDtor
+    value: true
+  - key: cppcoreguidelines-special-member-functions.AllowMissingMoveFunctions
+    value: true
 WarningsAsErrors: '*'
 # It is unclear if the header filter actually works or how to use it so
 # just include all headers

src/Evolution/DiscontinuousGalerkin/Actions/ApplyBoundaryCorrections.hpp

@@ -309,8 +309,12 @@ bool receive_boundary_data_local_time_stepping(
             neighbor_mortar_data.insert_neighbor_mortar_data(
                 receive_temporal_id, std::get<1>(received_mortar_data->second),
                 std::move(*std::get<3>(received_mortar_data->second)));
-            boundary_data_history->at(mortar_id).remote_insert(
-                receive_temporal_id, std::move(neighbor_mortar_data));
+            // We don't yet communicate the integration order, because
+            // we don't have any variable-order methods.  The
+            // fixed-order methods ignore the field.
+            boundary_data_history->at(mortar_id).remote().insert(
+                receive_temporal_id, std::numeric_limits<size_t>::max(),
+                std::move(neighbor_mortar_data));
           }
         }
         return true;

src/Evolution/DiscontinuousGalerkin/Actions/ComputeTimeDerivative.hpp

@@ -849,10 +849,9 @@ void ComputeTimeDerivative<Dim, EvolutionSystem, DgStepChoosers,
                          << " because the unordered map has not been "
                             "initialized "
                             "to have the mortar id.");
-              boundary_data_history->at(mortar_id).local_insert(
-                  time_step_id, std::move(mortar_data->at(mortar_id)));
-              boundary_data_history->at(mortar_id).integration_order(
-                  integration_order);
+              boundary_data_history->at(mortar_id).local().insert(
+                  time_step_id, integration_order,
+                  std::move(mortar_data->at(mortar_id)));
               mortar_data->at(mortar_id) = MortarData<Dim>{};
             }
           }