indices iterator for layers

src/core/sense.rs

@@ -138,10 +138,10 @@ impl<Ctx> SensorModule<Ctx> {
 
 impl<Ctx: UiCtx + 'static> SensorModule<Ctx> {
     pub fn run(ctx: &mut Ctx, cursor: &CursorState, window_size: Vec2) {
-        let mut layers = std::mem::take(&mut ctx.ui().layers);
+        let layers = std::mem::take(&mut ctx.ui().layers);
         let mut module = std::mem::take(ctx.ui().modules.get_mut::<Self>());
 
-        for (i, _) in layers.iter_mut().rev() {
+        for i in layers.indices().rev() {
             let Some(list) = module.active.get_mut(&i) else {
                 continue;
             };