Deprecated Begone! 0.16 Cleanup (#19108)

# Objective

A fair few items were deprecated in 0.16. Let's delete them now that
we're in the 0.17 development cycle!

## Solution

- Deleted items marked deprecated in 0.16.

## Testing

- CI

---

## Notes

I'm making the assumption that _everything_ deprecated in 0.16 should be
removed in 0.17. That may be a false assumption in certain cases. Please
check the items to be removed to see if there are any exceptions we
should keep around for another cycle!

Author: bushrat011899

crates/bevy_asset/src/handle.rs

@@ -11,7 +11,6 @@ use core::{
 use crossbeam_channel::{Receiver, Sender};
 use disqualified::ShortName;
 use thiserror::Error;
-use uuid::Uuid;
 
 /// Provides [`Handle`] and [`UntypedHandle`] _for a specific asset type_.
 /// This should _only_ be used for one specific asset type.
@@ -149,17 +148,6 @@ impl<T: Asset> Clone for Handle<T> {
 }
 
 impl<A: Asset> Handle<A> {
-    /// Create a new [`Handle::Weak`] with the given [`u128`] encoding of a [`Uuid`].
-    #[deprecated(
-        since = "0.16.0",
-        note = "use the `weak_handle!` macro with a UUID string instead"
-    )]
-    pub const fn weak_from_u128(value: u128) -> Self {
-        Handle::Weak(AssetId::Uuid {
-            uuid: Uuid::from_u128(value),
-        })
-    }
-
     /// Returns the [`AssetId`] of this [`Asset`].
     #[inline]
     pub fn id(&self) -> AssetId<A> {
@@ -554,6 +542,7 @@ mod tests {
     use bevy_platform::hash::FixedHasher;
     use bevy_reflect::PartialReflect;
     use core::hash::BuildHasher;
+    use uuid::Uuid;
 
     use super::*;
 

crates/bevy_ecs/README.md

@@ -290,7 +290,7 @@ struct MyEvent {
 }
 
 fn writer(mut writer: EventWriter<MyEvent>) {
-    writer.send(MyEvent {
+    writer.write(MyEvent {
         message: "hello!".to_string(),
     });
 }

crates/bevy_ecs/src/component.rs

@@ -509,15 +509,6 @@ pub trait Component: Send + Sync + 'static {
     /// * For a component to be immutable, this type must be [`Immutable`].
     type Mutability: ComponentMutability;
 
-    /// Called when registering this component, allowing mutable access to its [`ComponentHooks`].
-    #[deprecated(
-        since = "0.16.0",
-        note = "Use the individual hook methods instead (e.g., `Component::on_add`, etc.)"
-    )]
-    fn register_component_hooks(hooks: &mut ComponentHooks) {
-        hooks.update_from_component::<Self>();
-    }
-
     /// Gets the `on_add` [`ComponentHook`] for this [`Component`] if one is defined.
     fn on_add() -> Option<ComponentHook> {
         None
@@ -694,7 +685,7 @@ pub struct HookContext {
 /// This information is stored in the [`ComponentInfo`] of the associated component.
 ///
 /// There is two ways of configuring hooks for a component:
-/// 1. Defining the [`Component::register_component_hooks`] method (see [`Component`])
+/// 1. Defining the relevant hooks on the [`Component`] implementation
 /// 2. Using the [`World::register_component_hooks`] method
 ///
 /// # Example 2
@@ -1810,12 +1801,7 @@ impl<'w> ComponentsRegistrator<'w> {
                 .debug_checked_unwrap()
         };
 
-        #[expect(
-            deprecated,
-            reason = "need to use this method until it is removed to ensure user defined components register hooks correctly"
-        )]
-        // TODO: Replace with `info.hooks.update_from_component::<T>();` once `Component::register_component_hooks` is removed
-        T::register_component_hooks(&mut info.hooks);
+        info.hooks.update_from_component::<T>();
 
         info.required_components = required_components;
     }

crates/bevy_ecs/src/event/writer.rs

@@ -98,38 +98,4 @@ impl<'w, E: Event> EventWriter<'w, E> {
     {
         self.events.send_default()
     }
-
-    /// Sends an `event`, which can later be read by [`EventReader`](super::EventReader)s.
-    /// This method returns the [ID](`EventId`) of the sent `event`.
-    ///
-    /// See [`Events`] for details.
-    #[deprecated(since = "0.16.0", note = "Use `EventWriter::write` instead.")]
-    #[track_caller]
-    pub fn send(&mut self, event: E) -> EventId<E> {
-        self.write(event)
-    }
-
-    /// Sends a list of `events` all at once, which can later be read by [`EventReader`](super::EventReader)s.
-    /// This is more efficient than sending each event individually.
-    /// This method returns the [IDs](`EventId`) of the sent `events`.
-    ///
-    /// See [`Events`] for details.
-    #[deprecated(since = "0.16.0", note = "Use `EventWriter::write_batch` instead.")]
-    #[track_caller]
-    pub fn send_batch(&mut self, events: impl IntoIterator<Item = E>) -> SendBatchIds<E> {
-        self.write_batch(events)
-    }
-
-    /// Sends the default value of the event. Useful when the event is an empty struct.
-    /// This method returns the [ID](`EventId`) of the sent `event`.
-    ///
-    /// See [`Events`] for details.
-    #[deprecated(since = "0.16.0", note = "Use `EventWriter::write_default` instead.")]
-    #[track_caller]
-    pub fn send_default(&mut self) -> EventId<E>
-    where
-        E: Default,
-    {
-        self.write_default()
-    }
 }

crates/bevy_ecs/src/hierarchy.rs

@@ -106,13 +106,6 @@ impl ChildOf {
     pub fn parent(&self) -> Entity {
         self.0
     }
-
-    /// The parent entity of this child entity.
-    #[deprecated(since = "0.16.0", note = "Use child_of.parent() instead")]
-    #[inline]
-    pub fn get(&self) -> Entity {
-        self.0
-    }
 }
 
 // TODO: We need to impl either FromWorld or Default so ChildOf can be registered as Reflect.
@@ -344,20 +337,6 @@ impl<'w> EntityWorldMut<'w> {
         });
         self
     }
-
-    /// Removes the [`ChildOf`] component, if it exists.
-    #[deprecated(since = "0.16.0", note = "Use entity_mut.remove::<ChildOf>()")]
-    pub fn remove_parent(&mut self) -> &mut Self {
-        self.remove::<ChildOf>();
-        self
-    }
-
-    /// Inserts the [`ChildOf`] component with the given `parent` entity, if it exists.
-    #[deprecated(since = "0.16.0", note = "Use entity_mut.insert(ChildOf(entity))")]
-    pub fn set_parent(&mut self, parent: Entity) -> &mut Self {
-        self.insert(ChildOf(parent));
-        self
-    }
 }
 
 impl<'a> EntityCommands<'a> {
@@ -434,20 +413,6 @@ impl<'a> EntityCommands<'a> {
         self.with_related::<ChildOf>(bundle);
         self
     }
-
-    /// Removes the [`ChildOf`] component, if it exists.
-    #[deprecated(since = "0.16.0", note = "Use entity_commands.remove::<ChildOf>()")]
-    pub fn remove_parent(&mut self) -> &mut Self {
-        self.remove::<ChildOf>();
-        self
-    }
-
-    /// Inserts the [`ChildOf`] component with the given `parent` entity, if it exists.
-    #[deprecated(since = "0.16.0", note = "Use entity_commands.insert(ChildOf(entity))")]
-    pub fn set_parent(&mut self, parent: Entity) -> &mut Self {
-        self.insert(ChildOf(parent));
-        self
-    }
 }
 
 /// An `on_insert` component hook that when run, will validate that the parent of a given entity

crates/bevy_ecs/src/lib.rs

@@ -64,10 +64,6 @@ pub use bevy_ptr as ptr;
 ///
 /// This includes the most common types in this crate, re-exported for your convenience.
 pub mod prelude {
-    #[expect(
-        deprecated,
-        reason = "`crate::schedule::apply_deferred` is considered deprecated; however, it may still be used by crates which consume `bevy_ecs`, so its removal here may cause confusion. It is intended to be removed in the Bevy 0.17 cycle."
-    )]
     #[doc(hidden)]
     pub use crate::{
         bundle::Bundle,
@@ -86,8 +82,8 @@ pub mod prelude {
         removal_detection::RemovedComponents,
         resource::Resource,
         schedule::{
-            apply_deferred, common_conditions::*, ApplyDeferred, Condition, IntoScheduleConfigs,
-            IntoSystemSet, Schedule, Schedules, SystemSet,
+            common_conditions::*, ApplyDeferred, Condition, IntoScheduleConfigs, IntoSystemSet,
+            Schedule, Schedules, SystemSet,
         },
         spawn::{Spawn, SpawnRelated},
         system::{

crates/bevy_ecs/src/query/state.rs

@@ -1800,16 +1800,6 @@ impl<D: QueryData, F: QueryFilter> QueryState<D, F> {
         self.query(world).single_inner()
     }
 
-    /// A deprecated alias for [`QueryState::single`].
-    #[deprecated(since = "0.16.0", note = "Please use `single` instead.")]
-    #[inline]
-    pub fn get_single<'w>(
-        &mut self,
-        world: &'w World,
-    ) -> Result<ROQueryItem<'w, D>, QuerySingleError> {
-        self.single(world)
-    }
-
     /// Returns a single mutable query result when there is exactly one entity matching
     /// the query.
     ///
@@ -1827,15 +1817,6 @@ impl<D: QueryData, F: QueryFilter> QueryState<D, F> {
         self.query_mut(world).single_inner()
     }
 
-    /// A deprecated alias for [`QueryState::single_mut`].
-    #[deprecated(since = "0.16.0", note = "Please use `single` instead.")]
-    pub fn get_single_mut<'w>(
-        &mut self,
-        world: &'w mut World,
-    ) -> Result<D::Item<'w>, QuerySingleError> {
-        self.single_mut(world)
-    }
-
     /// Returns a query result when there is exactly one entity matching the query.
     ///
     /// If the number of query results is not exactly one, a [`QuerySingleError`] is returned

crates/bevy_ecs/src/schedule/executor/mod.rs

@@ -123,17 +123,6 @@ impl SystemSchedule {
     }
 }
 
-/// See [`ApplyDeferred`].
-#[deprecated(
-    since = "0.16.0",
-    note = "Use `ApplyDeferred` instead. This was previously a function but is now a marker struct System."
-)]
-#[expect(
-    non_upper_case_globals,
-    reason = "This item is deprecated; as such, its previous name needs to stay."
-)]
-pub const apply_deferred: ApplyDeferred = ApplyDeferred;
-
 /// A special [`System`] that instructs the executor to call
 /// [`System::apply_deferred`] on the systems that have run but not applied
 /// their [`Deferred`] system parameters (like [`Commands`]) or other system buffers.

crates/bevy_ecs/src/system/commands/mod.rs

@@ -1749,14 +1749,6 @@ impl<'a> EntityCommands<'a> {
     pub fn despawn(&mut self) {
         self.queue_handled(entity_command::despawn(), warn);
     }
-    /// Despawns the provided entity and its descendants.
-    #[deprecated(
-        since = "0.16.0",
-        note = "Use entity.despawn(), which now automatically despawns recursively."
-    )]
-    pub fn despawn_recursive(&mut self) {
-        self.despawn();
-    }
 
     /// Despawns the entity.
     ///