starting on conflict resolution

include/engine/guidance/turn_instruction.hpp

@@ -125,7 +125,7 @@ struct TurnInstruction
 
     static TurnInstruction NO_TURN()
     {
-        return TurnInstruction(TurnType::NoTurn, DirectionModifier::Straight);
+        return TurnInstruction(TurnType::NoTurn, DirectionModifier::UTurn);
     }
 
     static TurnInstruction REMAIN_ROUNDABOUT(const DirectionModifier modifier)
@@ -142,6 +142,11 @@ struct TurnInstruction
     {
         return TurnInstruction(TurnType::ExitRoundabout, modifier);
     }
+
+    static TurnInstruction SUPPRESSED(const DirectionModifier modifier)
+    {
+        return TurnInstruction{TurnType::Suppressed,modifier};
+    }
 };
 
 inline bool operator!=(const TurnInstruction lhs, const TurnInstruction rhs)

include/extractor/turn_analysis.hpp

@@ -188,6 +188,12 @@ AnalyzeTurn(const NodeID node_u,
             const NodeID node_w,
             const double angle,
             const std::shared_ptr<const util::NodeBasedDynamicGraph> node_based_graph);
+
+std::vector<TurnCandidate>
+handleConflicts(const NodeID from,
+                const EdgeID via_edge,
+                std::vector<TurnCandidate> turn_candidates,
+                const std::shared_ptr<const util::NodeBasedDynamicGraph> node_based_graph);
 } // namespace detail
 } // namespace turn_analysis
 } // namespace extractor