Add a new HashMap implementation

Adds a new, cleaned up, HashMap implementation.

* Uses Robin Hood Hashing (https://en.wikipedia.org/wiki/Hash_table#Robin_Hood_hashing).
* Keeps elements in a double linked list for simpler, ordered, iteration.
* Allows keeping iterators for later use in removal (Unlike Map<>, it does not do much
  for performance vs keeping the key, but helps replace old code).
* Uses a more modern C++ iterator API, deprecates the old one.
* Supports custom allocator (in case there is a wish to use a paged one).

This class aims to unify all the associative template usage and replace it by this one:
* Map<> (whereas key order does not matter, which is 99% of cases)
* HashMap<>
* OrderedHashMap<>
* OAHashMap<>

1 files changed, 2 insertions, 3 deletions

diff --git a/core/object/object.h b/core/object/object.h
index c3e3c68b59..00cb73593b 100644
--- a/core/object/object.h
+++ b/core/object/object.h
@@ -39,7 +39,6 @@
 #include "core/templates/hash_map.h"
 #include "core/templates/list.h"
 #include "core/templates/map.h"
-#include "core/templates/ordered_hash_map.h"
 #include "core/templates/safe_refcount.h"
 #include "core/templates/set.h"
 #include "core/templates/vmap.h"
@@ -515,8 +514,8 @@ private:
 #endif
 	ScriptInstance *script_instance = nullptr;
 	Variant script; // Reference does not exist yet, store it in a Variant.
-	OrderedHashMap<StringName, Variant> metadata;
-	HashMap<StringName, OrderedHashMap<StringName, Variant>::Element> metadata_properties;
+	HashMap<StringName, Variant> metadata;
+	HashMap<StringName, Variant *> metadata_properties;
 	mutable StringName _class_name;
 	mutable const StringName *_class_ptr = nullptr;