Replace boost::unordered_{map/set} with std, also remove code duplication

src/engine/hint.cpp

@@ -3,10 +3,10 @@
 #include "engine/datafacade/datafacade_base.hpp"
 
 #include <boost/assert.hpp>
-#include <boost/unordered_set.hpp>
 
 #include <algorithm>
 #include <iterator>
+#include <unordered_set>
 #include <tuple>
 
 namespace osrm
@@ -106,8 +106,8 @@ bool Hint::IsValid(const util::Coordinate new_input_coordinates,
 
     // Check hints do not contain duplicate segment pairs
     // We can't allow duplicates as search heaps do not support it.
-    boost::unordered_set<NodeID> forward_segments;
-    boost::unordered_set<NodeID> reverse_segments;
+    std::unordered_set<NodeID> forward_segments;
+    std::unordered_set<NodeID> reverse_segments;
     for (const auto &seg_hint : segment_hints)
     {
         const auto forward_res = forward_segments.insert(seg_hint.phantom.forward_segment_id.id);

src/extractor/edge_based_graph_factory.cpp

@@ -34,20 +34,6 @@
 #include <tbb/parallel_for.h>
 #include <tbb/parallel_pipeline.h>
 
-namespace std
-{
-template <> struct hash<std::pair<NodeID, NodeID>>
-{
-    std::size_t operator()(const std::pair<NodeID, NodeID> &mk) const noexcept
-    {
-        std::size_t seed = 0;
-        boost::hash_combine(seed, mk.first);
-        boost::hash_combine(seed, mk.second);
-        return seed;
-    }
-};
-} // namespace std
-
 namespace osrm
 {
 namespace extractor
@@ -1283,7 +1269,7 @@ void EdgeBasedGraphFactory::GenerateEdgeExpandedEdges(
 std::vector<ConditionalTurnPenalty>
 EdgeBasedGraphFactory::IndexConditionals(std::vector<Conditional> &&conditionals) const
 {
-    boost::unordered_multimap<std::pair<NodeID, NodeID>, ConditionalTurnPenalty *> index;
+    std::unordered_multimap<std::pair<NodeID, NodeID>, ConditionalTurnPenalty *> index;
 
     // build and index of all conditional restrictions
     for (auto &conditional : conditionals)