3 files changed, 59 insertions, 40 deletions

diff --git a/src/server/game/Entities/Object/Object.cpp b/src/server/game/Entities/Object/Object.cpp
index 86e742426e0..66a9124befd 100644
--- a/src/server/game/Entities/Object/Object.cpp
+++ b/src/server/game/Entities/Object/Object.cpp
@@ -70,7 +70,7 @@ constexpr float VisibilityDistances[AsUnderlyingType(VisibilityDistanceType::Max
     MAX_VISIBILITY_DISTANCE
 };
 
-Object::Object() : m_values(this), m_scriptRef(this, NoopObjectDeleter())
+Object::Object() : m_scriptRef(this, NoopObjectDeleter())
 {
     m_objectTypeId      = TYPEID_OBJECT;
     m_objectType        = TYPEMASK_OBJECT;
diff --git a/src/server/game/Entities/Object/Object.h b/src/server/game/Entities/Object/Object.h
index 55d6e2e1d18..0fdeed66e7d 100644
--- a/src/server/game/Entities/Object/Object.h
+++ b/src/server/game/Entities/Object/Object.h
@@ -107,6 +107,30 @@ struct CreateObjectBits
 
 namespace UF
 {
+    class UpdateFieldHolder
+    {
+    public:
+        template<typename Derived, typename T, int32 BlockBit, uint32 Bit>
+        inline MutableFieldReference<T, false> ModifyValue(UpdateField<T, BlockBit, Bit>(Derived::* field));
+
+        template<typename Derived, typename T, int32 BlockBit, uint32 Bit>
+        inline void ClearChangesMask(UpdateField<T, BlockBit, Bit>(Derived::* field));
+
+        uint32 GetChangedObjectTypeMask() const { return _changesMask; }
+
+        bool HasChanged(uint32 index) const { return (_changesMask & UpdateMaskHelpers::GetBlockFlag(index)) != 0; }
+
+        inline Object* GetOwner();
+
+    private:
+        friend Object;
+
+        // This class is tightly tied to Object::m_values member, do not construct elsewhere
+        UpdateFieldHolder() : _changesMask(0) { }
+
+        uint32 _changesMask;
+    };
+
     template<typename T>
     inline bool SetUpdateFieldValue(UpdateFieldSetter<T>& setter, typename UpdateFieldSetter<T>::value_type&& value)
     {
@@ -264,6 +288,7 @@ class TC_GAME_API Object
         Conversation* ToConversation() { if (IsConversation()) return reinterpret_cast<Conversation*>(this); else return nullptr; }
         Conversation const* ToConversation() const { if (IsConversation()) return reinterpret_cast<Conversation const*>(this); else return nullptr; }
 
+        friend UF::UpdateFieldHolder;
         UF::UpdateFieldHolder m_values;
         UF::UpdateField<UF::ObjectData, 0, TYPEID_OBJECT> m_objectData;
 
@@ -425,6 +450,36 @@ class TC_GAME_API Object
         Object& operator=(Object&& right) = delete;
 };
 
+inline Object* UF::UpdateFieldHolder::GetOwner()
+{
+#if TRINITY_COMPILER == TRINITY_COMPILER_GNU
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winvalid-offsetof"
+#endif
+
+    return reinterpret_cast<Object*>(reinterpret_cast<std::byte*>(this) - offsetof(Object, m_values));
+
+#if TRINITY_COMPILER == TRINITY_COMPILER_GNU
+#pragma GCC diagnostic pop
+#endif
+}
+
+template <typename Derived, typename T, int32 BlockBit, uint32 Bit>
+inline UF::MutableFieldReference<T, false> UF::UpdateFieldHolder::ModifyValue(UpdateField<T, BlockBit, Bit> Derived::* field)
+{
+    Object* owner = GetOwner();
+    _changesMask |= UpdateMaskHelpers::GetBlockFlag(Bit);
+    return { (static_cast<Derived*>(owner)->*field)._value };
+}
+
+template <typename Derived, typename T, int32 BlockBit, uint32 Bit>
+inline void UF::UpdateFieldHolder::ClearChangesMask(UpdateField<T, BlockBit, Bit> Derived::* field)
+{
+    Object* owner = GetOwner();
+    _changesMask &= ~UpdateMaskHelpers::GetBlockFlag(Bit);
+    (static_cast<Derived*>(owner)->*field)._value.ClearChangesMask();
+}
+
 template <class T_VALUES, class T_FLAGS, class FLAG_TYPE, size_t ARRAY_SIZE>
 class FlaggedValuesArray32
 {
diff --git a/src/server/game/Entities/Object/Updates/UpdateField.h b/src/server/game/Entities/Object/Updates/UpdateField.h
index fdad7e0d18e..ebf07df9c28 100644
--- a/src/server/game/Entities/Object/Updates/UpdateField.h
+++ b/src/server/game/Entities/Object/Updates/UpdateField.h
@@ -672,42 +672,6 @@ namespace UF
         Mask _changesMask;
     };
 
-    class UpdateFieldHolder
-    {
-    public:
-        explicit UpdateFieldHolder(Object* owner) : _owner(owner)
-        {
-        }
-
-        template<typename Derived, typename T, int32 BlockBit, uint32 Bit>
-        MutableFieldReference<T, false> ModifyValue(UpdateField<T, BlockBit, Bit>(Derived::* field))
-        {
-            _changesMask.Set(Bit);
-            return { (static_cast<Derived*>(_owner)->*field)._value };
-        }
-
-        template<typename Derived, typename T, int32 BlockBit, uint32 Bit>
-        void ClearChangesMask(UpdateField<T, BlockBit, Bit>(Derived::* field))
-        {
-            _changesMask.Reset(Bit);
-            (static_cast<Derived*>(_owner)->*field)._value.ClearChangesMask();
-        }
-
-        uint32 GetChangedObjectTypeMask() const
-        {
-            return _changesMask.GetBlock(0);
-        }
-
-        bool HasChanged(uint32 index) const
-        {
-            return _changesMask[index];
-        }
-
-    private:
-        UpdateMask<NUM_CLIENT_OBJECT_TYPES> _changesMask;
-        Object* _owner;
-    };
-
     template<typename T>
     class UpdateFieldBase : public IsUpdateFieldHolderTag
     {
@@ -878,7 +842,7 @@ namespace UF
 
         bool HasChanged(uint32 index) const
         {
-            return (_updateMask[index / 32] & (1 << (index % 32))) != 0;
+            return (_updateMask[UpdateMaskHelpers::GetBlockIndex(index)] & UpdateMaskHelpers::GetBlockFlag(index)) != 0;
         }
 
         void WriteUpdateMask(ByteBuffer& data, int32 bitsForSize = 32) const
@@ -949,9 +913,9 @@ namespace UF
             return !!_value;
         }
 
-        operator T const& () const
+        operator bool const() const
         {
-            return *_value;
+            return has_value();
         }
         T const* operator->() const
         {