Make CoreCH SearchEngineData inherited from CH one

this allows to keep a single Algorithm template parameter in internal
interfaces as

template <typename Algorithm>
search(SearchEngineData<Algorithm> &,
       const datafacade::ContiguousInternalMemoryDataFacade<Algorithm> &, ...)

include/engine/engine.hpp

@@ -132,7 +132,7 @@ template <typename Algorithm> class Engine final : public EngineInterface
 
   private:
     std::unique_ptr<DataFacadeProvider<Algorithm>> facade_provider;
-    mutable SearchEngineData<typename RoutingAlgorithms<Algorithm>::HeapAlgorithm> heaps;
+    mutable SearchEngineData<Algorithm> heaps;
 
     const plugins::ViaRoutePlugin route_plugin;
     const plugins::TablePlugin table_plugin;

include/engine/routing_algorithms.hpp

@@ -57,16 +57,7 @@ class RoutingAlgorithmsInterface
 template <typename Algorithm> class RoutingAlgorithms final : public RoutingAlgorithmsInterface
 {
   public:
-    // HeapAlgorithm is an explicit heap algorithm type to be used with Algorithm
-    // - CH algorithms use CH heap
-    // - CoreCH algorithms use CH heap
-    // - MLD algorithms use MLD heap
-    using HeapAlgorithm = typename std::conditional<
-        std::is_same<Algorithm, routing_algorithms::corech::Algorithm>::value,
-        routing_algorithms::ch::Algorithm,
-        Algorithm>::type;
-
-    RoutingAlgorithms(SearchEngineData<HeapAlgorithm> &heaps,
+    RoutingAlgorithms(SearchEngineData<Algorithm> &heaps,
                       const datafacade::ContiguousInternalMemoryDataFacade<Algorithm> &facade)
         : heaps(heaps), facade(facade)
     {
@@ -131,7 +122,7 @@ template <typename Algorithm> class RoutingAlgorithms final : public RoutingAlgo
     }
 
   private:
-    SearchEngineData<HeapAlgorithm> &heaps;
+    SearchEngineData<Algorithm> &heaps;
 
     // Owned by shared-ptr passed to the query
     const datafacade::ContiguousInternalMemoryDataFacade<Algorithm> &facade;

include/engine/routing_algorithms/direct_shortest_path.hpp

@@ -27,7 +27,7 @@ InternalRouteResult directShortestPathSearch(
     const PhantomNodes &phantom_nodes);
 
 InternalRouteResult directShortestPathSearch(
-    SearchEngineData<ch::Algorithm> &engine_working_data,
+    SearchEngineData<corech::Algorithm> &engine_working_data,
     const datafacade::ContiguousInternalMemoryDataFacade<corech::Algorithm> &facade,
     const PhantomNodes &phantom_nodes);
 

include/engine/routing_algorithms/map_matching.hpp

@@ -22,8 +22,8 @@ static const constexpr double DEFAULT_GPS_PRECISION = 5;
 
 //[1] "Hidden Markov Map Matching Through Noise and Sparseness";
 //     P. Newson and J. Krumm; 2009; ACM GIS
-template <typename Algorithm, typename SearchEngineData>
-SubMatchingList mapMatching(SearchEngineData &engine_working_data,
+template <typename Algorithm>
+SubMatchingList mapMatching(SearchEngineData<Algorithm> &engine_working_data,
                             const datafacade::ContiguousInternalMemoryDataFacade<Algorithm> &facade,
                             const CandidateLists &candidates_list,
                             const std::vector<util::Coordinate> &trace_coordinates,

include/engine/routing_algorithms/shortest_path.hpp

@@ -13,9 +13,9 @@ namespace engine
 namespace routing_algorithms
 {
 
-template <typename Algorithm, typename SearchEngineData>
+template <typename Algorithm>
 InternalRouteResult
-shortestPathSearch(SearchEngineData &engine_working_data,
+shortestPathSearch(SearchEngineData<Algorithm> &engine_working_data,
                    const datafacade::ContiguousInternalMemoryDataFacade<Algorithm> &facade,
                    const std::vector<PhantomNodes> &phantom_nodes_vector,
                    const boost::optional<bool> continue_straight_at_waypoint);

include/engine/search_engine_data.hpp

@@ -12,6 +12,12 @@ namespace osrm
 namespace engine
 {
 
+// Algorithm-dependent heaps
+// - CH algorithms use CH heaps
+// - CoreCH algorithms use CoreCH heaps that can be upcasted to CH heaps when CH algorithms reused
+//    by CoreCH at calling ch::routingStep, ch::retrievePackedPathFromSingleHeap and ch::unpackPath
+// - MLD algorithms use MLD heaps
+
 template <typename Algorithm> struct SearchEngineData
 {
 };
@@ -59,6 +65,12 @@ template <> struct SearchEngineData<routing_algorithms::ch::Algorithm>
     void InitializeOrClearManyToManyThreadLocalStorage(unsigned number_of_nodes);
 };
 
+template <>
+struct SearchEngineData<routing_algorithms::corech::Algorithm>
+    : public SearchEngineData<routing_algorithms::ch::Algorithm>
+{
+};
+
 struct MultiLayerDijkstraHeapData
 {
     NodeID parent;