tokio::fs::File doesn't expose into_std() in 0.2

[bartlomieju]

Version

tokio 0.2

Description

In tokio 0.1 one could get underlying std::fs::File instance from tokio::fs::File like so:

OpenOptions::new().open().and_then(move |tokio_file| {
  let std_file = tokio_file.into_std();
});

Unfortunately I did not find this method in tokio 0.2 which is very desirable - eg. I want to start new Command with file as stdout/stderr for that command. Command.stdout() requires Into<Stdio> which is implemented for std::fs::File but not tokio::fs::File.

EDIT:
As I see that design of tokio::fs::File changed it's not really useful to destructure the file. Something like async fn try_clone_std() -> std::fs::File would be fine 👍

[carllerche]

what about async fn into_std?

[bartlomieju]

what about async fn into_std?

pub async fn into_std(&self) -> io::Result<sys::File> {
    let std = self.std.clone();
    let std_file = asyncify(move || std.try_clone()).await?;
    Ok(std_file)
}

@carllerche something along those lines? I'll be happy to open a PR

[carllerche]

You would not need a clone. You would wait until the background operation is complete, then downcast then use Arc::try_unwrap to get the inner file.

You could also have a try_into_std(self) -> Result<sys::File, Self> that does the Arc::try_unwrap directly.