Resolve "IsMotion used in Problem::getState()"

Closes #399 (closed)

include/core/problem/problem.h

@@ -178,10 +178,8 @@ class Problem : public std::enable_shared_from_this<Problem>
 
     public:
         IsMotionPtr getProcessorIsMotion();
-        std::map<int,IsMotionPtr> getProcessorIsMotionMap();
-        
-
-
+        std::map<int,IsMotionPtr>& getProcessorIsMotionMap();
+        const std::map<int,IsMotionPtr>& getProcessorIsMotionMap() const;
 
         // Trajectory branch ----------------------------------
         TrajectoryBasePtr getTrajectory() const;
@@ -437,8 +435,12 @@ inline IsMotionPtr Problem::getProcessorIsMotion()
     return nullptr;
 }
 
+inline std::map<int,IsMotionPtr>& Problem::getProcessorIsMotionMap()
+{
+    return processor_is_motion_map_;
+}
 
-inline std::map<int,IsMotionPtr> Problem::getProcessorIsMotionMap()
+inline const std::map<int,IsMotionPtr>& Problem::getProcessorIsMotionMap() const
 {
     return processor_is_motion_map_;
 }