48 lines
1022 B
Rust
48 lines
1022 B
Rust
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// compile-pass
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// edition:2018
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#![feature(arbitrary_self_types, async_await, await_macro)]
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use std::task::{self, Poll};
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use std::future::Future;
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use std::marker::Unpin;
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use std::pin::Pin;
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// This is a regression test for a ICE/unbounded recursion issue relating to async-await.
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#[derive(Debug)]
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#[must_use = "futures do nothing unless polled"]
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pub struct Lazy<F> {
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f: Option<F>
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}
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impl<F> Unpin for Lazy<F> {}
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pub fn lazy<F, R>(f: F) -> Lazy<F>
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where F: FnOnce(&mut task::Context) -> R,
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{
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Lazy { f: Some(f) }
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}
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impl<R, F> Future for Lazy<F>
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where F: FnOnce(&mut task::Context) -> R,
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{
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type Output = R;
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fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context) -> Poll<R> {
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Poll::Ready((self.f.take().unwrap())(cx))
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}
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}
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async fn __receive<WantFn, Fut>(want: WantFn) -> ()
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where Fut: Future<Output = ()>, WantFn: Fn(&Box<Send + 'static>) -> Fut,
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{
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await!(lazy(|_| ()));
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}
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pub fn basic_spawn_receive() {
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async { await!(__receive(|_| async { () })) };
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}
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fn main() {}
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