From 83e8224694702d1e9aab85811de21bbf4b054f07 Mon Sep 17 00:00:00 2001
From: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
Date: Mon, 5 Dec 2022 23:23:14 +0000
Subject: [PATCH] Add missing docs to `World::change_tick` and
 `World::read_change_tick` (#6765)

# Objective

The methods `World::change_tick` and `World::read_change_tick` lack documentation and have confusingly similar behavior.

## Solution

Add documentation and clarify the distinction between the two functions.
---
 crates/bevy_ecs/src/world/mod.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/crates/bevy_ecs/src/world/mod.rs b/crates/bevy_ecs/src/world/mod.rs
index b60fdb5ff2..c0ca9d4b85 100644
--- a/crates/bevy_ecs/src/world/mod.rs
+++ b/crates/bevy_ecs/src/world/mod.rs
@@ -1396,11 +1396,19 @@ impl World {
         self.change_tick.fetch_add(1, Ordering::AcqRel)
     }
 
+    /// Reads the current change tick of this world.
+    ///
+    /// If you have exclusive (`&mut`) access to the world, consider using [`change_tick()`](Self::change_tick),
+    /// which is more efficient since it does not require atomic synchronization.
     #[inline]
     pub fn read_change_tick(&self) -> u32 {
         self.change_tick.load(Ordering::Acquire)
     }
 
+    /// Reads the current change tick of this world.
+    ///
+    /// This does the same thing as [`read_change_tick()`](Self::read_change_tick), only this method
+    /// is more efficient since it does not require atomic synchronization.
     #[inline]
     pub fn change_tick(&mut self) -> u32 {
         *self.change_tick.get_mut()