don't move spawned array

Author: hymm

crates/bevy_tasks/src/task_pool.rs

@@ -2,7 +2,6 @@ use std::{
     future::Future,
     marker::PhantomData,
     mem,
-    pin::Pin,
     sync::Arc,
     thread::{self, JoinHandle},
 };
@@ -268,9 +267,9 @@ impl TaskPool {
         if spawned.is_empty() {
             Vec::new()
         } else {
-            let get_results = async move {
-                let mut results = Vec::with_capacity(spawned.len());
-                while let Ok(task) = spawned.pop() {
+            let get_results = async {
+                let mut results = Vec::with_capacity(spawned_ref.len());
+                while let Ok(task) = spawned_ref.pop() {
                     results.push(task.await.unwrap());
                 }
 
@@ -280,23 +279,8 @@ impl TaskPool {
             // Pin the futures on the stack.
             pin!(get_results);
 
-            // SAFETY: This function blocks until all futures complete, so we do not read/write
-            // the data from futures outside of the 'scope lifetime. However,
-            // rust has no way of knowing this so we must convert to 'static
-            // here to appease the compiler as it is unable to validate safety.
-            let get_results: Pin<&mut (dyn Future<Output = Vec<T>> + 'static + Send)> = get_results;
-            let get_results: Pin<&'static mut (dyn Future<Output = Vec<T>> + 'static + Send)> =
-                unsafe { mem::transmute(get_results) };
-
-            // The thread that calls scope() will participate in driving tasks in the pool
-            // forward until the tasks that are spawned by this scope() call
-            // complete. (If the caller of scope() happens to be a thread in
-            // this thread pool, and we only have one thread in the pool, then
-            // simply calling future::block_on(spawned) would deadlock.)
-            let mut spawned = task_scope_executor.spawn(get_results);
-
             loop {
-                if let Some(result) = future::block_on(future::poll_once(&mut spawned)) {
+                if let Some(result) = future::block_on(future::poll_once(&mut get_results)) {
                     break result;
                 };