Rust returns impl Future, and then calls this Future in Dart

[oo-work]

I hope that the impl Future<Output = String> returned by Rust can be called by Dart.

pub fn test_future_fn() -> impl Future<Output = String> + Send + 'static {
    async{
        String::from("Hello, world!")
    }
}

[fzyzcjy]

Hmm, you current code seems the same as

pub async fn test_future_fn() -> String {
  ...
}

And that's supported.

[oo-work]

No, I hope he is like this.

Future<Future<String> testFutureFn();

final future =  await testFutureFn();
...
...
...
final result = await future;
print(result);

[fzyzcjy]

Hmm what about

pub struct MyFuture(Box<dyn Future<Output = String> + Send + 'static>);

impl MyFuture {
  pub async fn await_me(self) -> String {
    self.0.await
  }
}

pub fn test_future_fn() -> MyFuture {
    MyFuture(Box::new(async {
        String::from("Hello, world!")
    }))
}

[oo-work]

It worked, it would be even better if he could call await in flutter naturally instead of .awaitMe()

[fzyzcjy]

Feel free to PR for this! This does not seem to be super frequently needed, so may not have top priority for me to implement.