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Hello,
I'm trying to find, in rust, in the most idiomatic way, to represent a resource (in a struct) that is to be initialized but in the future. Not in the new function.
Would it be better to use Option or Box ? Or is there a better option ?
In my specific case I have a struct meant to implement the Future trait. The main function of the future that I call (I didn't write the function, the code isn't mine, I use a third C library) has a callback as an argument that is called when the result is ready.
It looks something like this:
struct MyFutureStruct {
// ...some other ressources....
result_created: bool,
waker: Option<Waker> // is this good ? or should I use Box or something else ?
}
impl Future for MyFutureStruct {
type Output = ...;
fn poll(self: Pin<&mut Self>, ctx: &mut Context<'_>) -> Poll<Self::Output> {
match self.result_created {
false => {
// something like this - more like a pseudo code here
// this callback is called when the result is created and ready to be used
self.waker = Some(ctx.waker().clone());
let callback = result_created_callback
// call the main third library function here
create_result(callback)
}
true => {
// here the callback was called
}
}
}
fn result_callback_created(user_data) {
// here user_data is Self
self.waker.unwrap().wake_by_ref()
self.result_created = true
}
}
As you can see, I'm not sure whether Option is the best way to contain the Waker.
Hoping I was clear enough.
Thank you very much in advance for any help.
3 posts - 2 participants
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