C++ specific fixes...

src/rt/objects/dyn_object.h

@@ -353,7 +353,7 @@ namespace rt::objects
   template<typename Pre, typename Post>
   inline void visit(Region* start, Pre pre, Post post)
   {
-    for (auto obj : start->objects)
+    for (auto obj : start->get_objects())
     {
       visit(obj, pre, post);
     }

src/rt/objects/region.h

@@ -200,9 +200,11 @@ namespace rt::objects
       collecting = true;
 
       std::cout << "Starting collection" << std::endl;
-      for (auto r : to_collect)
+      while (!to_collect.empty())
       {
+        auto r = *to_collect.begin();
         dirty_regions.erase(r);
+        to_collect.erase(r);
         // Note destruct could re-enter here, ensure we don't hold onto a
         // pointer into to_collect.
         for (auto o : r->objects)
@@ -214,7 +216,6 @@ namespace rt::objects
         delete r;
       }
       std::cout << "Finished collection" << std::endl;
-      to_collect.clear();
       collecting = false;
     }
   };

src/rt/rt.cc

@@ -116,7 +116,9 @@ namespace rt
   objects::DynObject*
   set(objects::DynObject* obj, std::string key, objects::DynObject* value)
   {
-    assert(obj && "Given nullptr, expected a valid DynObject pointer");
+    if (!obj) {
+      ui::error("fields can't be set on `None`");
+    }
     return obj->set(key, value);
   }