51 lines
990 B
Rust
51 lines
990 B
Rust
use std::{
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future::Future,
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marker::PhantomData,
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pin::Pin,
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task::{Context, Poll},
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};
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pub trait Try: Sized {
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fn tri<F>(f: F) -> Result<(), Self>
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where
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F: FnOnce() -> Result<(), Self>;
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fn tria<F>(f: F) -> Tria<Self, F>
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where
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F: Future<Output = Result<(), Self>>;
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}
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impl<E> Try for E {
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fn tri<F>(f: F) -> Result<(), Self>
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where
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F: FnOnce() -> Result<(), Self>,
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{
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f()
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}
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fn tria<F>(f: F) -> Tria<E, F>
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where
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F: Future<Output = Result<(), Self>>,
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{
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Tria {
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f,
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_phantom: Default::default(),
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}
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}
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}
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pub struct Tria<E, F> {
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f: F,
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_phantom: PhantomData<E>,
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}
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impl<E, F> Future for Tria<E, F>
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where
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F: Future<Output = Result<(), E>>,
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{
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type Output = Result<(), E>;
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fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
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unsafe { Pin::new_unchecked(&mut Pin::get_unchecked_mut(self).f).poll(cx) }
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}
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}
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