feat: benchmark despawning an entity

benches/ecs/mod.rs

@@ -17,6 +17,35 @@ pub fn world_spawn(c: &mut Criterion) {
  });
 }
 
+/// Benchmarks despawning an entity in a [`World`].
+pub fn world_despawn(c: &mut Criterion) {
+ c.bench_function("world_despawn", |b| {
+ let mut world = World::new();
+
+ let unsafe_world_cell = world.as_unsafe_world_cell();
+
+ b.iter_batched(
+ || {
+ // SAFETY: The `&mut World` returned by this is always dropped before the routine
+ // accesses the world.
+ let world = unsafe { unsafe_world_cell.world_mut() };
+
+ world.spawn_batch(repeat((A(0), B(0))).take(64))
+ },
+ |input| {
+ // SAFETY: The `&mut World` return by this is always dropped before the setup
+ // acceses the world.
+ let world = unsafe { unsafe_world_cell.world_mut() };
+
+ for entity in input {
+ world.despawn(entity);
+ }
+ },
+ BatchSize::SmallInput,
+ );
+ });
+}
+
 /// Benchmarks iterating over all matching entities within a [`World`].
 pub fn world_query_iter(c: &mut Criterion) {
  c.bench_function("world_query_iter", |b| {
@@ -58,4 +87,10 @@ pub fn world_get_entity(c: &mut Criterion) {
  });
 }
 
-criterion_group!(group, world_spawn, world_query_iter, world_get_entity);
+criterion_group!(
+ group,
+ world_spawn,
+ world_despawn,
+ world_query_iter,
+ world_get_entity
+);

benches/ecs/types.rs

@@ -4,10 +4,10 @@ use bevy::ecs::prelude::*;
 ///
 /// This is intended to not match with [`B`]'s size, to force the ECS to deal with padding.
 #[derive(Component, Clone)]
-pub struct A(pub u32);
+pub struct A(#[allow(dead_code)] pub u32);
 
 /// A 16-bit wide component.
 ///
 /// This is intended to not match with [`A`]'s size, to force the ECS to deal with padding.
 #[derive(Component, Clone)]
-pub struct B(pub u16);
+pub struct B(#[allow(dead_code)] pub u16);