bevy/crates/bevy_tasks/src/task.rs

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use std::{
future::Future,
pin::Pin,
task::{Context, Poll},
};
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/// Wraps `async_executor::Task`, a spawned future.
///
/// Tasks are also futures themselves and yield the output of the spawned future.
///
/// When a task is dropped, its gets canceled and won't be polled again. To cancel a task a bit
/// more gracefully and wait until it stops running, use the [`cancel()`][Task::cancel()] method.
///
/// Tasks that panic get immediately canceled. Awaiting a canceled task also causes a panic.
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/// Wraps async_executor::Task
pub struct Task<T>(async_executor::Task<T>);
impl<T> Task<T> {
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/// Detaches the task to let it keep running in the background. See `async_executor::Task::detach`
pub fn detach(self) {
self.0.detach();
}
/// Cancels the task and waits for it to stop running.
///
/// Returns the task's output if it was completed just before it got canceled, or [`None`] if
/// it didn't complete.
///
/// While it's possible to simply drop the [`Task`] to cancel it, this is a cleaner way of
/// canceling because it also waits for the task to stop running.
///
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/// See `async_executor::Task::cancel`
pub async fn cancel(self) -> Option<T> {
self.0.cancel().await
}
}
impl<T> Future for Task<T> {
type Output = T;
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fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
Pin::new(&mut self.0).poll(cx)
}
}