Nightly clippy fixes (#2702)

A few minor changes to fix warnings emitted from clippy on the nightly toolchain, including redundant_allocation, unwrap_or_else_default, and collapsible_match, fixes #2698

crates/bevy_asset/src/asset_server.rs

@@ -53,7 +53,7 @@ pub struct AssetServerInternal {
     pub(crate) asset_ref_counter: AssetRefCounter,
     pub(crate) asset_sources: Arc<RwLock<HashMap<SourcePathId, SourceInfo>>>,
     pub(crate) asset_lifecycles: Arc<RwLock<HashMap<Uuid, Box<dyn AssetLifecycle>>>>,
-    loaders: RwLock<Vec<Arc<Box<dyn AssetLoader>>>>,
+    loaders: RwLock<Vec<Arc<dyn AssetLoader>>>,
     extension_to_loader_index: RwLock<HashMap<String, usize>>,
     handle_to_path: Arc<RwLock<HashMap<HandleId, AssetPath<'static>>>>,
     task_pool: TaskPool,
@@ -112,7 +112,7 @@ impl AssetServer {
                 .write()
                 .insert(extension.to_string(), loader_index);
         }
-        loaders.push(Arc::new(Box::new(loader)));
+        loaders.push(Arc::new(loader));
     }
 
     pub fn watch_for_changes(&self) -> Result<(), AssetServerError> {
@@ -130,10 +130,7 @@ impl AssetServer {
         HandleUntyped::strong(id.into(), sender)
     }
 
-    fn get_asset_loader(
-        &self,
-        extension: &str,
-    ) -> Result<Arc<Box<dyn AssetLoader>>, AssetServerError> {
+    fn get_asset_loader(&self, extension: &str) -> Result<Arc<dyn AssetLoader>, AssetServerError> {
         let index = {
             // scope map to drop lock as soon as possible
             let map = self.server.extension_to_loader_index.read();
@@ -149,7 +146,7 @@ impl AssetServer {
     fn get_path_asset_loader<P: AsRef<Path>>(
         &self,
         path: P,
-    ) -> Result<Arc<Box<dyn AssetLoader>>, AssetServerError> {
+    ) -> Result<Arc<dyn AssetLoader>, AssetServerError> {
         let s = path
             .as_ref()
             .file_name()

crates/bevy_core/src/lib.rs

@@ -43,7 +43,7 @@ impl Plugin for CorePlugin {
         app.world
             .get_resource::<DefaultTaskPoolOptions>()
             .cloned()
-            .unwrap_or_else(DefaultTaskPoolOptions::default)
+            .unwrap_or_default()
             .create_default_pools(&mut app.world);
 
         app.init_resource::<Time>()

crates/bevy_reflect/bevy_reflect_derive/src/lib.rs

@@ -557,9 +557,7 @@ pub fn impl_reflect_value(input: TokenStream) -> TokenStream {
 
     let bevy_reflect_path = BevyManifest::default().get_path("bevy_reflect");
     let ty = &reflect_value_def.type_name;
-    let reflect_attrs = reflect_value_def
-        .attrs
-        .unwrap_or_else(ReflectAttrs::default);
+    let reflect_attrs = reflect_value_def.attrs.unwrap_or_default();
     let registration_data = &reflect_attrs.data;
     let get_type_registration_impl = impl_get_type_registration(
         ty,

crates/bevy_wgpu/src/lib.rs

@@ -112,7 +112,7 @@ pub fn get_wgpu_render_system(world: &mut World) -> impl FnMut(&mut World) {
     let options = world
         .get_resource::<WgpuOptions>()
         .cloned()
-        .unwrap_or_else(WgpuOptions::default);
+        .unwrap_or_default();
     let mut wgpu_renderer = future::block_on(WgpuRenderer::new(options));
 
     let resource_context = WgpuRenderResourceContext::new(wgpu_renderer.device.clone());