From b0cc6bfd7ef0c82a306cfcfa15f16463774a8e7c Mon Sep 17 00:00:00 2001
From: Stepan Koltsov <stepan.koltsov@gmail.com>
Date: Wed, 22 Nov 2023 20:20:39 +0000
Subject: [PATCH] Rustdoc example for Ref (#10682)

---
 crates/bevy_ecs/src/change_detection.rs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/crates/bevy_ecs/src/change_detection.rs b/crates/bevy_ecs/src/change_detection.rs
index 0e6483600b..27a6c08c1c 100644
--- a/crates/bevy_ecs/src/change_detection.rs
+++ b/crates/bevy_ecs/src/change_detection.rs
@@ -623,6 +623,28 @@ impl<'a, T: 'static> From<NonSendMut<'a, T>> for Mut<'a, T> {
 
 /// Shared borrow of an entity's component with access to change detection.
 /// Similar to [`Mut`] but is immutable and so doesn't require unique access.
+///
+/// # Examples
+///
+/// These two systems produce the same output.
+///
+/// ```
+/// # use bevy_ecs::change_detection::DetectChanges;
+/// # use bevy_ecs::query::{Changed, With};
+/// # use bevy_ecs::system::Query;
+/// # use bevy_ecs::world::Ref;
+/// # use bevy_ecs_macros::Component;
+/// # #[derive(Component)]
+/// # struct MyComponent;
+///
+/// fn how_many_changed_1(query: Query<(), Changed<MyComponent>>) {
+///     println!("{} changed", query.iter().count());
+/// }
+///
+/// fn how_many_changed_2(query: Query<Ref<MyComponent>>) {
+///     println!("{} changed", query.iter().filter(|c| c.is_changed()).count());
+/// }
+/// ```
 pub struct Ref<'a, T: ?Sized> {
     pub(crate) value: &'a T,
     pub(crate) ticks: Ticks<'a>,