remove typed stuff / just specify rsc if needed

src/default/task.rs

@@ -62,17 +62,14 @@ impl<Rsc: HasState> Tasks<Rsc> {
         )
     }
 
-    pub fn spawn<F: for<'a> AsyncFnOnce(&'a mut TaskCtx<Rsc>) + 'static + std::marker::Send>(
-        &mut self,
-        task: F,
-    ) where
-        for<'a> <F as AsyncFnOnce<(&'a mut TaskCtx<Rsc>,)>>::CallOnceFuture: Send,
+    pub fn spawn<F: AsyncFnOnce(TaskCtx<Rsc>) + 'static + std::marker::Send>(&mut self, task: F)
+    where
+        F::CallOnceFuture: Send,
     {
         let send = self.msg_send.clone();
         let window = self.window.clone();
         let _ = self.start.send(Box::pin(async move {
-            let mut ctx = TaskCtx::new(send);
-            task(&mut ctx).await;
+            task(TaskCtx::new(send)).await;
             window.request_redraw();
         }));
     }