rust/tests/ui/coroutine/iterator-count.rs
Oli Scherer aef0f4024a Error on using yield without also using #[coroutine] on the closure
And suggest adding the `#[coroutine]` to the closure
2024-04-24 08:05:29 +00:00

46 lines
968 B
Rust

//@ run-pass
#![feature(coroutines, coroutine_trait)]
use std::ops::{Coroutine, CoroutineState};
use std::pin::Pin;
struct W<T>(T);
// This impl isn't safe in general, but the coroutine used in this test is movable
// so it won't cause problems.
impl<T: Coroutine<(), Return = ()> + Unpin> Iterator for W<T> {
type Item = T::Yield;
fn next(&mut self) -> Option<Self::Item> {
match Pin::new(&mut self.0).resume(()) {
CoroutineState::Complete(..) => None,
CoroutineState::Yielded(v) => Some(v),
}
}
}
fn test() -> impl Coroutine<(), Return = (), Yield = u8> + Unpin {
#[coroutine]
|| {
for i in 1..6 {
yield i
}
}
}
fn main() {
let end = 11;
let closure_test = |start| {
#[coroutine]
move || {
for i in start..end {
yield i
}
}
};
assert!(W(test()).chain(W(closure_test(6))).eq(1..11));
}