prototype new Fields as propertyWrappers (Swift 5.2 above only)

Sources/CoreStoreObject+Observing.swift

@@ -27,6 +27,33 @@ import Foundation
 import CoreData
 
 
+extension DynamicObject where Self: CoreStoreObject {
+
+    public func observe<O, V>(_ keyPath: KeyPath<Self, FieldContainer<O>.Stored<V>>, options: NSKeyValueObservingOptions = [], changeHandler: @escaping (Self, CoreStoreObjectValueDiff<V>) -> Void) -> CoreStoreObjectKeyValueObservation {
+
+        let result = _CoreStoreObjectKeyValueObservation(
+            object: self.rawObject!,
+            keyPath: self[keyPath: keyPath].keyPath,
+            callback: { (object, kind, newValue, oldValue, _, isPrior) in
+
+                let notification = CoreStoreObjectValueDiff<V>(
+                    kind: kind,
+                    newNativeValue: newValue as? V.QueryableNativeType,
+                    oldNativeValue: oldValue as? V.QueryableNativeType,
+                    isPrior: isPrior
+                )
+                changeHandler(
+                    Self.cs_fromRaw(object: object),
+                    notification
+                )
+            }
+        )
+        result.start(options)
+        return result
+    }
+}
+
+
 // MARK: CoreStoreObjectKeyValueObservation
 
 /**