Remove spawn_and_forget

It's unused, and was only ever needed for the weird extract logic

Remove the trick because it's actually stupid

Author: DJMcNab

crates/bevy_ecs/src/system/commands/mod.rs

@@ -118,12 +118,6 @@ impl<'w, 's> Commands<'w, 's> {
         }
     }
 
-    /// Spawns a [`Bundle`] without pre-allocating an [`Entity`]. The [`Entity`] will be allocated
-    /// when this [`Command`] is applied.
-    pub fn spawn_and_forget(&mut self, bundle: impl Bundle) {
-        self.queue.push(Spawn { bundle });
-    }
-
     /// Creates a new entity with the components contained in `bundle`.
     ///
     /// This returns an [`EntityCommands`] builder, which enables inserting more components and

crates/bevy_render/src/extract_param.rs

@@ -1,9 +1,7 @@
 use crate::MainWorld;
 use bevy_ecs::{
     prelude::*,
-    system::{
-        ReadOnlySystemParamFetch, SystemParam, SystemParamFetch, SystemParamItem, SystemState,
-    },
+    system::{ReadOnlySystemParamFetch, SystemParam, SystemParamItem, SystemState},
 };
 
 pub struct MainWorldState<P: SystemParam>(SystemState<P>);
@@ -19,11 +17,8 @@ pub struct Extract<'w, 's, P: SystemParam + 'static>
 where
     P::Fetch: ReadOnlySystemParamFetch,
 {
-    state: Local<
-        's,
-        MainWorldState<<<P as SystemParam>::Fetch as SystemParamFetch<'static, 'static>>::Item>,
-    >,
-    world: Res<'w, World>,
+    state: Local<'s, MainWorldState<P>>,
+    world: Res<'w, MainWorld>,
 }
 
 impl<'w, 's, P: SystemParam + 'static> Extract<'w, 's, P>

crates/bevy_render/src/lib.rs

@@ -313,11 +313,11 @@ fn extract(app_world: &mut World, render_app: &mut App) {
     // temporarily add the app world to the render world as a resource
     let scratch_world = app_world.remove_resource::<ScratchMainWorld>().unwrap();
     let inserted_world = std::mem::replace(app_world, scratch_world.0);
-    let mut running_world = &mut render_app.world;
+    let running_world = &mut render_app.world;
     running_world.insert_resource(MainWorld(inserted_world));
 
-    extract.run(&mut running_world);
-    extract.apply_buffers(&mut running_world);
+    extract.run(running_world);
+    extract.apply_buffers(running_world);
 
     // move the app world back, as if nothing happened.
     let inserted_world = running_world.remove_resource::<MainWorld>().unwrap();