fix subscriptions in events

packages/copy/Cargo.toml

@@ -14,4 +14,4 @@ rand = "0.8.5"
 
 [features]
 default = ["check_generation"]
-check_generation = []
+check_generation = []

packages/copy/src/lib.rs

@@ -193,6 +193,17 @@ impl<T: 'static> CopyHandle<T> {
     pub fn write(&self) -> RefMut<'_, T> {
         self.try_write().unwrap()
     }
+
+    pub fn ptr_eq(&self, other: &Self) -> bool {
+        #[cfg(any(debug_assertions, feature = "check_generation"))]
+        {
+            self.raw.data.as_ptr() == other.raw.data.as_ptr() && self.generation == other.generation
+        }
+        #[cfg(not(any(debug_assertions, feature = "check_generation")))]
+        {
+            self.raw.data.as_ptr() == other.raw.data.as_ptr()
+        }
+    }
 }
 
 impl<T> Copy for CopyHandle<T> {}