Feature/add spawn with (#516)

* Adds send bound to arbiter exec

* Adds spawn with function


---------

Co-authored-by: James Bell <jamesbell@microsoft.com>

ntex-rt/CHANGES.md

@@ -1,6 +1,8 @@
 # Changes
 
-## [0.4.26] - 2025-03-12
+## [0.4.27] - 2025-03-14
+
+* Add Arbiter::spawn_with()
 
 * Add "neon" runtime support
 
@@ -8,6 +10,10 @@
 
 * Drop async-std support
 
+## [0.4.26] - 2025-03-12
+
+* Add Arbiter::spawn_with()
+
 ## [0.4.25] - 2025-03-11
 
 * Adds Send bound to arbiter exec (#514)

ntex-rt/src/arbiter.rs

@@ -154,6 +154,27 @@ impl Arbiter {
             .try_send(ArbiterCommand::Execute(Box::pin(future)));
     }
 
+    /// Send a function to the Arbiter's thread and spawns it's resulting future.
+    /// This can be used to spawn non-send futures on the arbiter thread.
+    pub fn spawn_with<F, R, O>(&self, f: F) -> impl Future<Output = Result<O, oneshot::RecvError>> + Send + 'static
+    where
+        F: FnOnce() -> R + Send + 'static,
+        R: Future<Output = O> + 'static,
+        O: Send + 'static
+    {
+        let (tx, rx) = oneshot::channel();
+        let _ = self
+            .sender
+            .try_send(ArbiterCommand::ExecuteFn(Box::new(move || {
+                let fut = f();
+                let fut = Box::pin(async {
+                    let _ = tx.send(fut.await);
+                });
+                crate::spawn(fut);
+            })));
+        rx
+    }
+
     #[rustfmt::skip]
     /// Send a function to the Arbiter's thread. This function will be executed asynchronously.
     /// A future is created, and when resolved will contain the result of the function sent