Revert "ecs: remove &mut requirement on query iterators"

This reverts commit 6dc1d07.

crates/bevy_core/src/label.rs

@@ -68,7 +68,7 @@ pub fn entity_labels_system(
     mut query: Query<(Entity, &Labels)>,
 ) {
     let entity_labels = entity_labels.deref_mut();
-    for (entity, labels) in query.iter() {
+    for (entity, labels) in &mut query.iter() {
         let current_labels = entity_labels
             .entity_labels
             .entry(entity)

crates/bevy_core/src/time/timer.rs

@@ -38,7 +38,7 @@ impl Timer {
 }
 
 pub fn timer_system(time: Res<Time>, mut query: Query<&mut Timer>) {
-    for mut timer in query.iter() {
+    for mut timer in &mut query.iter() {
         timer.tick(time.delta_seconds);
     }
 }

crates/bevy_ecs/hecs/benches/bench.rs

@@ -68,7 +68,7 @@ fn iterate_100k(b: &mut Bencher) {
         world.spawn((Position(-(i as f32)), Velocity(i as f32)));
     }
     b.iter(|| {
-        for (mut pos, vel) in world.query::<(&mut Position, &Velocity)>() {
+        for (mut pos, vel) in &mut world.query::<(&mut Position, &Velocity)>() {
             pos.0 += vel.0;
         }
     })

crates/bevy_ecs/hecs/src/query.rs

@@ -321,7 +321,7 @@ impl<'w, Q: Query> QueryBorrow<'w, Q> {
     /// Execute the query
     ///
     /// Must be called only once per query.
-    pub fn iter(mut self) -> QueryIter<'w, Q> {
+    pub fn iter<'q>(&'q mut self) -> QueryIter<'q, 'w, Q> {
         self.borrow();
         QueryIter {
             borrow: self,
@@ -434,27 +434,27 @@ impl<'w, Q: Query> Drop for QueryBorrow<'w, Q> {
     }
 }
 
-impl<'w, Q: Query> IntoIterator for QueryBorrow<'w, Q> {
-    type Item = <Q::Fetch as Fetch<'w>>::Item;
-    type IntoIter = QueryIter<'w, Q>;
+impl<'q, 'w, Q: Query> IntoIterator for &'q mut QueryBorrow<'w, Q> {
+    type Item = <Q::Fetch as Fetch<'q>>::Item;
+    type IntoIter = QueryIter<'q, 'w, Q>;
 
     fn into_iter(self) -> Self::IntoIter {
         self.iter()
     }
 }
 
 /// Iterator over the set of entities with the components in `Q`
-pub struct QueryIter<'w, Q: Query> {
-    borrow: QueryBorrow<'w, Q>,
+pub struct QueryIter<'q, 'w, Q: Query> {
+    borrow: &'q mut QueryBorrow<'w, Q>,
     archetype_index: u32,
     iter: Option<ChunkIter<Q>>,
 }
 
-unsafe impl<'w, Q: Query> Send for QueryIter<'w, Q> {}
-unsafe impl<'w, Q: Query> Sync for QueryIter<'w, Q> {}
+unsafe impl<'q, 'w, Q: Query> Send for QueryIter<'q, 'w, Q> {}
+unsafe impl<'q, 'w, Q: Query> Sync for QueryIter<'q, 'w, Q> {}
 
-impl<'w, Q: Query> Iterator for QueryIter<'w, Q> {
-    type Item = <Q::Fetch as Fetch<'w>>::Item;
+impl<'q, 'w, Q: Query> Iterator for QueryIter<'q, 'w, Q> {
+    type Item = <Q::Fetch as Fetch<'q>>::Item;
 
     #[inline]
     fn next(&mut self) -> Option<Self::Item> {
@@ -489,7 +489,7 @@ impl<'w, Q: Query> Iterator for QueryIter<'w, Q> {
     }
 }
 
-impl<'w, Q: Query> ExactSizeIterator for QueryIter<'w, Q> {
+impl<'q, 'w, Q: Query> ExactSizeIterator for QueryIter<'q, 'w, Q> {
     fn len(&self) -> usize {
         self.borrow
             .archetypes

crates/bevy_ecs/hecs/src/world.rs

@@ -481,7 +481,6 @@ impl World {
     ///
     /// See `remove`.
     pub fn remove_one<T: Component>(&mut self, entity: Entity) -> Result<T, ComponentError> {
-        std::println!("reomve {} ", std::any::type_name::<T>());
         self.remove::<(T,)>(entity).map(|(x,)| x)
     }
 

crates/bevy_ecs/hecs/tests/tests.rs

@@ -261,6 +261,17 @@ fn clear() {
     assert_eq!(world.iter().count(), 0);
 }
 
+#[test]
+#[should_panic(expected = "twice on the same borrow")]
+fn alias() {
+    let mut world = World::new();
+    world.spawn(("abc", 123));
+    world.spawn(("def", 456, true));
+    let mut q = world.query::<&mut i32>();
+    let _a = q.iter().collect::<Vec<_>>();
+    let _b = q.iter().collect::<Vec<_>>();
+}
+
 #[test]
 fn remove_missing() {
     let mut world = World::new();

crates/bevy_ecs/src/system/into_system.rs

@@ -158,10 +158,6 @@ impl<'a, Q: HecsQuery> Query<'a, Q> {
                 .archetype_access
                 .immutable
                 .contains(location.archetype as usize)
-                || self
-                    .archetype_access
-                    .mutable
-                    .contains(location.archetype as usize)
             {
                 self.world
                     .get(entity)

crates/bevy_render/src/camera/active_cameras.rs

@@ -27,7 +27,7 @@ pub fn active_cameras_system(
 ) {
     for (name, active_camera) in active_cameras.cameras.iter_mut() {
         if let None = active_camera {
-            for (camera_entity, camera) in query.iter() {
+            for (camera_entity, camera) in &mut query.iter() {
                 if let Some(ref current_name) = camera.name {
                     if current_name == name {
                         *active_camera = Some(camera_entity);

crates/bevy_render/src/camera/camera.rs

@@ -62,7 +62,7 @@ pub fn camera_system<T: CameraProjection + Component>(
         }
     }
 
-    for (mut camera, mut camera_projection) in query.iter() {
+    for (mut camera, mut camera_projection) in &mut query.iter() {
         if let Some(window) = match camera.window {
             WindowReference::Id(id) => {
                 if changed_window_ids.contains(&id) {

crates/bevy_render/src/camera/visible_entities.rs

@@ -26,13 +26,13 @@ pub fn visible_entities_system(
     mut draw_query: Query<(Entity, &Draw)>,
     draw_transform_query: Query<(&Draw, &Transform)>,
 ) {
-    for (_camera, camera_transform, mut visible_entities) in camera_query.iter() {
+    for (_camera, camera_transform, mut visible_entities) in &mut camera_query.iter() {
         visible_entities.value.clear();
         let camera_position = camera_transform.value.w_axis().truncate();
 
         let mut no_transform_order = 0.0;
         let mut transparent_entities = Vec::new();
-        for (entity, draw) in draw_query.iter() {
+        for (entity, draw) in &mut draw_query.iter() {
             if !draw.is_visible {
                 continue;
             }

crates/bevy_render/src/draw.rs

@@ -366,7 +366,7 @@ pub trait Drawable {
 }
 
 pub fn clear_draw_system(mut query: Query<&mut Draw>) {
-    for mut draw in query.iter() {
+    for mut draw in &mut query.iter() {
         draw.clear_render_commands();
     }
 }

crates/bevy_render/src/mesh/mesh.rs

@@ -479,7 +479,7 @@ pub fn mesh_resource_provider_system(
     }
 
     // TODO: remove this once batches are pipeline specific and deprecate assigned_meshes draw target
-    for (handle, mut render_pipelines) in query.iter() {
+    for (handle, mut render_pipelines) in &mut query.iter() {
         if let Some(mesh) = meshes.get(&handle) {
             for render_pipeline in render_pipelines.pipelines.iter_mut() {
                 render_pipeline.specialization.primitive_topology = mesh.primitive_topology;

crates/bevy_render/src/pipeline/render_pipelines.rs

@@ -106,7 +106,7 @@ pub fn draw_render_pipelines_system(
     mut render_resource_bindings: ResMut<RenderResourceBindings>,
     mut query: Query<(&mut Draw, &mut RenderPipelines)>,
 ) {
-    for (mut draw, mut render_pipelines) in query.iter() {
+    for (mut draw, mut render_pipelines) in &mut query.iter() {
         let mut drawable = DrawableRenderPipelines {
             render_pipelines: &mut render_pipelines,
             render_resource_bindings: &mut render_resource_bindings,

crates/bevy_render/src/render_graph/nodes/render_resources_node.rs

@@ -422,7 +422,7 @@ fn render_resources_node_system<T: RenderResources>(
     let render_resource_context = &**render_resource_context;
     state.uniform_buffer_arrays.reset_changed_item_counts();
     // update uniforms info
-    for (uniforms, draw, _render_pipelines) in query.iter() {
+    for (uniforms, draw, _render_pipelines) in &mut query.iter() {
         if !draw.is_visible {
             return;
         }
@@ -438,7 +438,7 @@ fn render_resources_node_system<T: RenderResources>(
         .uniform_buffer_arrays
         .update_staging_buffer(render_resource_context);
 
-    for (uniforms, draw, mut render_pipelines) in query.iter() {
+    for (uniforms, draw, mut render_pipelines) in &mut query.iter() {
         if !draw.is_visible {
             return;
         }
@@ -456,7 +456,7 @@ fn render_resources_node_system<T: RenderResources>(
             staging_buffer,
             0..state.uniform_buffer_arrays.staging_buffer_size as u64,
             &mut |mut staging_buffer, _render_resource_context| {
-                for (uniforms, draw, mut render_pipelines) in query.iter() {
+                for (uniforms, draw, mut render_pipelines) in &mut query.iter() {
                     if !draw.is_visible {
                         return;
                     }
@@ -479,7 +479,7 @@ fn render_resources_node_system<T: RenderResources>(
     } else {
         // TODO: can we just remove this?
         let mut staging_buffer: [u8; 0] = [];
-        for (uniforms, draw, mut render_pipelines) in query.iter() {
+        for (uniforms, draw, mut render_pipelines) in &mut query.iter() {
             if !draw.is_visible {
                 return;
             }
@@ -657,7 +657,7 @@ fn asset_render_resources_node_system<T: RenderResources>(
         }
     }
 
-    for (asset_handle, _draw, mut render_pipelines) in query.iter() {
+    for (asset_handle, _draw, mut render_pipelines) in &mut query.iter() {
         if let Some(asset_bindings) = asset_render_resource_bindings.get(*asset_handle) {
             render_pipelines.bindings.extend(asset_bindings);
         }

crates/bevy_render/src/shader/shader_defs.rs

@@ -59,7 +59,7 @@ pub fn shader_defs_system<T>(mut query: Query<(&T, &mut RenderPipelines)>)
 where
     T: ShaderDefs + Send + Sync + 'static,
 {
-    for (shader_defs, mut render_pipelines) in query.iter() {
+    for (shader_defs, mut render_pipelines) in &mut query.iter() {
         for shader_def in shader_defs.iter_shader_defs() {
             for render_pipeline in render_pipelines.pipelines.iter_mut() {
                 render_pipeline
@@ -73,7 +73,7 @@ where
 }
 
 pub fn clear_shader_defs_system(mut query: Query<&mut RenderPipelines>) {
-    for mut render_pipelines in query.iter() {
+    for mut render_pipelines in &mut query.iter() {
         for render_pipeline in render_pipelines.pipelines.iter_mut() {
             render_pipeline
                 .specialization
@@ -90,7 +90,7 @@ pub fn asset_shader_defs_system<T>(
 ) where
     T: ShaderDefs + Send + Sync + 'static,
 {
-    for (asset_handle, mut render_pipelines) in query.iter() {
+    for (asset_handle, mut render_pipelines) in &mut query.iter() {
         let shader_defs = assets.get(&asset_handle).unwrap();
         for shader_def in shader_defs.iter_shader_defs() {
             for render_pipeline in render_pipelines.pipelines.iter_mut() {

crates/bevy_sprite/src/sprite.rs

@@ -23,7 +23,7 @@ pub fn sprite_system(
     textures: Res<Assets<Texture>>,
     mut query: Query<(&mut Sprite, &Handle<ColorMaterial>)>,
 ) {
-    for (mut sprite, handle) in query.iter() {
+    for (mut sprite, handle) in &mut query.iter() {
         let material = materials.get(&handle).unwrap();
         if let Some(texture_handle) = material.texture {
             if let Some(texture) = textures.get(&texture_handle) {

crates/bevy_transform/src/hierarchy/hierarchy_maintenance_system.rs

@@ -9,7 +9,7 @@ pub fn missing_previous_parent_system(
     mut query: Query<Without<PreviousParent, (Entity, &Parent)>>,
 ) {
     // Add missing `PreviousParent` components
-    for (entity, _parent) in query.iter() {
+    for (entity, _parent) in &mut query.iter() {
         log::trace!("Adding missing PreviousParent to {:?}", entity);
         commands.insert_one(entity, PreviousParent(None));
     }
@@ -24,7 +24,7 @@ pub fn parent_update_system(
 ) {
     // Entities with a missing `Parent` (ie. ones that have a `PreviousParent`), remove
     // them from the `Children` of the `PreviousParent`.
-    for (entity, previous_parent) in removed_parent_query.iter() {
+    for (entity, previous_parent) in &mut removed_parent_query.iter() {
         log::trace!("Parent was removed from {:?}", entity);
         if let Some(previous_parent_entity) = previous_parent.0 {
             if let Ok(mut previous_parent_children) =
@@ -40,7 +40,7 @@ pub fn parent_update_system(
     let mut children_additions = HashMap::<Entity, SmallVec<[Entity; 8]>>::with_capacity(16);
 
     // Entities with a changed Parent (that also have a PreviousParent, even if None)
-    for (entity, parent, mut previous_parent) in changed_parent_query.iter() {
+    for (entity, parent, mut previous_parent) in &mut changed_parent_query.iter() {
         log::trace!("Parent changed for {:?}", entity);
 
         // If the `PreviousParent` is not None.

crates/bevy_transform/src/local_transform_systems.rs

@@ -13,7 +13,7 @@ pub fn local_transform_translation_system(
         >,
     >,
 ) {
-    for (mut local, translation) in query.iter() {
+    for (mut local, translation) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_translation(translation.0));
     }
 }
@@ -26,7 +26,7 @@ pub fn local_transform_rotation_system(
         >,
     >,
 ) {
-    for (mut local, rotation) in query.iter() {
+    for (mut local, rotation) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_quat(rotation.0));
     }
 }
@@ -39,7 +39,7 @@ pub fn local_transform_scale_system(
         >,
     >,
 ) {
-    for (mut local, scale) in query.iter() {
+    for (mut local, scale) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_scale(Vec3::new(scale.0, scale.0, scale.0)));
     }
 }
@@ -52,7 +52,7 @@ pub fn local_transform_non_uniform_scale_system(
         >,
     >,
 ) {
-    for (mut local, non_uniform_scale) in query.iter() {
+    for (mut local, non_uniform_scale) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_scale(non_uniform_scale.0));
     }
 }
@@ -62,7 +62,7 @@ pub fn local_transform_translation_rotation_system(
         Without<Scale, Without<NonUniformScale, (&mut LocalTransform, &Translation, &Rotation)>>,
     >,
 ) {
-    for (mut local, translation, rotation) in query.iter() {
+    for (mut local, translation, rotation) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_rotation_translation(rotation.0, translation.0));
     }
 }
@@ -72,7 +72,7 @@ pub fn local_transform_translation_scale_system(
         Without<Rotation, Without<NonUniformScale, (&mut LocalTransform, &Translation, &Scale)>>,
     >,
 ) {
-    for (mut local, translation, scale) in query.iter() {
+    for (mut local, translation, scale) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_scale_rotation_translation(
             Vec3::new(scale.0, scale.0, scale.0),
             Quat::default(),
@@ -86,7 +86,7 @@ pub fn local_transform_translation_non_uniform_scale_system(
         Without<Rotation, Without<Scale, (&mut LocalTransform, &Translation, &NonUniformScale)>>,
     >,
 ) {
-    for (mut local, translation, non_uniform_scale) in query.iter() {
+    for (mut local, translation, non_uniform_scale) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_scale_rotation_translation(
             non_uniform_scale.0,
             Quat::default(),
@@ -100,7 +100,7 @@ pub fn local_transform_rotation_scale_system(
         Without<Translation, Without<NonUniformScale, (&mut LocalTransform, &Rotation, &Scale)>>,
     >,
 ) {
-    for (mut local, rotation, scale) in query.iter() {
+    for (mut local, rotation, scale) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_scale_rotation_translation(
             Vec3::new(scale.0, scale.0, scale.0),
             rotation.0,
@@ -114,7 +114,7 @@ pub fn local_transform_rotation_non_uniform_scale_system(
         Without<Translation, Without<Scale, (&mut LocalTransform, &Rotation, &NonUniformScale)>>,
     >,
 ) {
-    for (mut local, rotation, non_uniform_scale) in query.iter() {
+    for (mut local, rotation, non_uniform_scale) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_scale_rotation_translation(
             non_uniform_scale.0,
             rotation.0,
@@ -128,7 +128,7 @@ pub fn local_transform_translation_rotation_scale_system(
         Without<NonUniformScale, (&mut LocalTransform, &Translation, &Rotation, &Scale)>,
     >,
 ) {
-    for (mut local, translation, rotation, scale) in query.iter() {
+    for (mut local, translation, rotation, scale) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_scale_rotation_translation(
             Vec3::new(scale.0, scale.0, scale.0),
             rotation.0,
@@ -150,7 +150,7 @@ pub fn local_transform_translation_rotation_non_uniform_scale_system(
         >,
     >,
 ) {
-    for (mut local, translation, rotation, non_uniform_scale) in query.iter() {
+    for (mut local, translation, rotation, non_uniform_scale) in &mut query.iter() {
         *local = LocalTransform(Mat4::from_scale_rotation_translation(
             non_uniform_scale.0,
             rotation.0,

crates/bevy_transform/src/transform_propagate_system.rs

@@ -10,7 +10,7 @@ pub fn transform_propagate_system(
     mut children_query: Query<&Children>,
     mut local_transform_query: Query<&LocalTransform>,
 ) {
-    for (children, mut transform, local_transform) in root_query.iter() {
+    for (children, mut transform, local_transform) in &mut root_query.iter() {
         if let Some(local_transform) = local_transform {
             transform.value = local_transform.0;
         }