fix constness

Author: rhaschke

core/include/moveit/task_constructor/container_p.h

@@ -230,7 +230,7 @@ class MergerPrivate : public ParallelContainerBasePrivate
 	using ChildSolutionList = std::vector<const SubTrajectory*>;
 	using ChildSolutionMap = std::map<const Stage*, ChildSolutionList>;
 	// map from external source state (iterator) to all corresponding children's solutions
-	std::map<InterfaceState*, ChildSolutionMap> source_state_to_solutions_;
+	std::map<const InterfaceState*, ChildSolutionMap> source_state_to_solutions_;
 
 public:
 	using Spawner = std::function<void(SubTrajectory&&)>;

core/src/container.cpp

@@ -883,7 +883,7 @@ void MergerPrivate::onNewPropagateSolution(const SolutionBase& s) {
 	auto source_it = internalToExternalMap().find(source_state);
 	// internal->external mapping for source state should have been created
 	assert(source_it != internalToExternalMap().end());
-	InterfaceState* external_source_state = &*source_it->second;
+	const InterfaceState* external_source_state = &*source_it->second;
 
 	// retrieve (or create if necessary) the ChildSolutionMap for the given external source state
 	ChildSolutionMap& all_solutions =