map_set_apply.md

---

title: "Reflection-based maps are now unordered"
pull_requests: [19802]

---

DynamicMap is now unordered, and the Map trait no longer assumes implementors to be ordered. If you previously relied on them being ordered, you should now store a list of keys (Vec<Box<dyn PartialReflect>>) separately.

Map::get_at and Map::get_at_mut are now removed. You should no longer use usize to index into the map, and instead use &dyn PartialReflect with Map::get and Map::get_mut.

PartialReflect::apply(self, other) for maps now removes excess entries (entries present in self which are not present in other). If you need those entries to be preserved, you will need to re-insert them manually.