Switching to Linux to find a memory bug and I want to keep a record of what caused it.

worldbuilder.hpp

@@ -8,11 +8,11 @@
 class WorldBuilder {
   public:
   Map& $map;
-  std::shared_ptr<SpatialMap> $collision;
+  SpatialMap& $collision;
 
-  WorldBuilder(Map &map) :
+  WorldBuilder(Map &map, SpatialMap& collision) :
     $map(map),
-    $collision(std::make_shared<SpatialMap>())
+    $collision(collision)
   { }
 
   void generate_map();