From f0a98645d0dcc3dc76ad335755adb074f6fbe5db Mon Sep 17 00:00:00 2001
From: Yasha Borevich <jkbo@funexpected.org>
Date: Sun, 10 Mar 2024 13:46:50 +0100
Subject: [PATCH] Implement MutUntyped::from(mut_typed) (#12406)

# Objective

Allow to create MutUntyped<'a> instance from Mut<'a, T>.
Fixes #12405

## Solution

Added impl<'a, T> From<Mut<'a, T>> for MutUntyped<'>
---
 crates/bevy_ecs/src/change_detection.rs | 34 +++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/crates/bevy_ecs/src/change_detection.rs b/crates/bevy_ecs/src/change_detection.rs
index 7fda0a13f9..bca6aa2a38 100644
--- a/crates/bevy_ecs/src/change_detection.rs
+++ b/crates/bevy_ecs/src/change_detection.rs
@@ -938,6 +938,15 @@ impl std::fmt::Debug for MutUntyped<'_> {
     }
 }
 
+impl<'w, T> From<Mut<'w, T>> for MutUntyped<'w> {
+    fn from(value: Mut<'w, T>) -> Self {
+        MutUntyped {
+            value: value.value.into(),
+            ticks: value.ticks,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use bevy_ecs_macros::Resource;
@@ -1254,4 +1263,29 @@ mod tests {
 
         assert!(new.is_changed());
     }
+
+    #[test]
+    fn mut_untyped_from_mut() {
+        let mut component_ticks = ComponentTicks {
+            added: Tick::new(1),
+            changed: Tick::new(2),
+        };
+        let ticks = TicksMut {
+            added: &mut component_ticks.added,
+            changed: &mut component_ticks.changed,
+            last_run: Tick::new(3),
+            this_run: Tick::new(4),
+        };
+        let mut c = C {};
+        let mut_typed = Mut {
+            value: &mut c,
+            ticks,
+        };
+
+        let into_mut: MutUntyped = mut_typed.into();
+        assert_eq!(1, into_mut.ticks.added.get());
+        assert_eq!(2, into_mut.ticks.changed.get());
+        assert_eq!(3, into_mut.ticks.last_run.get());
+        assert_eq!(4, into_mut.ticks.this_run.get());
+    }
 }