From 45a1f0515f63d4d6574d6c29d35f2ee4df42c1bf Mon Sep 17 00:00:00 2001
From: Carter Anderson <mcanders1@gmail.com>
Date: Thu, 30 Apr 2020 23:59:05 -0700
Subject: [PATCH] use immutable reference in FromResources

---
 crates/bevy_app/src/resources.rs | 6 +++---
 crates/bevy_derive/src/lib.rs    | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_app/src/resources.rs b/crates/bevy_app/src/resources.rs
index 9f16abd5bf..324b0c5cc3 100644
--- a/crates/bevy_app/src/resources.rs
+++ b/crates/bevy_app/src/resources.rs
@@ -2,14 +2,14 @@ use crate::{EventReader, GetEventReader};
 use legion::prelude::Resources;
 
 pub trait FromResources {
-    fn from_resources(resources: &mut Resources) -> Self;
+    fn from_resources(resources: &Resources) -> Self;
 }
 
 impl<T> FromResources for T
 where
     T: Default,
 {
-    default fn from_resources(_resources: &mut Resources) -> Self {
+    default fn from_resources(_resources: &Resources) -> Self {
         Self::default()
     }
 }
@@ -18,7 +18,7 @@ impl<T> FromResources for EventReader<T>
 where
     T: Send + Sync + 'static,
 {
-    fn from_resources(resources: &mut Resources) -> Self {
+    fn from_resources(resources: &Resources) -> Self {
         resources.get_event_reader::<T>()
     }
 }
diff --git a/crates/bevy_derive/src/lib.rs b/crates/bevy_derive/src/lib.rs
index e051826ae3..419e553580 100644
--- a/crates/bevy_derive/src/lib.rs
+++ b/crates/bevy_derive/src/lib.rs
@@ -143,7 +143,7 @@ pub fn derive_resource(input: TokenStream) -> TokenStream {
 
     TokenStream::from(quote! {
         impl #impl_generics #bevy_app_path::FromResources for #struct_name#ty_generics {
-            fn from_resources(resources: &mut Resources) -> Self {
+            fn from_resources(resources: &Resources) -> Self {
                 use #bevy_app_path::FromResources;
                 #struct_name {
                     #(#fields: <#field_types>::from_resources(resources),)*