Add run_until_cancelled_owned to CancellationToken

[tysen]

Pretty natural addition to match the cancelled_owned fn.

Motivation

let token = CancellationToken::new();
tokio::spawn(token.run_until_cancelled(my_async_fn())); // doesn't compile
tokio::spawn(async move { // current workaround
    token.run_until_cancelled(my_async_fn())).await
});
tokio::spawn(token.run_until_cancelled_owned(my_async_fn())); // compiles, looks nicer

Solution

Just a carbon copy of the existing fn switching to the appropriate cancellation future.

[tysen]

Thanks for the review @tglane! I have modified the commit as you requested.

[tglane]

Know this type basically is a biased select future I think because C technically is not required to be some sort of CancellationToken. I think we could replace the usage of this type with a tokio::select! if we add the macros feature to tokio-utils tokio dependency. @Darksonn do you have a optionion on that?

[Darksonn]

Is there a reason that this PR is not just this?

pub async fn run_until_cancelled_owned<F>(self, fut: F) -> Option<F::Output>
where
    F: Future,
{
    self.run_until_cancelled(fut).await
}

I believe it should be sufficient - the async/await syntax takes care of making it owned.

[tglane]

Is there a reason that this PR is not just this?

pub async fn run_until_cancelled_owned<F>(self, fut: F) -> Option<F::Output>
where
    F: Future,
{
    self.run_until_cancelled(fut).await
}

I believe it should be sufficient - the async/await syntax takes care of making it owned.

Oh yeah, you are right that works! So that would be an even better approach here.

[tysen]

Oh wow yeah I definitely overcomplicated this 🤦

[tglane]

Apart from this nit it looks good to me know.

[tglane]

The docs should mention the difference to run_until_cancelled in some way.
Maybe add something like this to the docs:

///
/// The function takes self by value and returns a future that owns the
/// token.