rust/tests/ui/coroutine/postfix-yield.rs
2025-04-15 11:14:23 +02:00

34 lines
934 B
Rust

// This demonstrates a proposed alternate or additional option of having yield in postfix position.
//@ run-pass
//@ edition: 2024
#![feature(gen_blocks, coroutines, coroutine_trait, yield_expr, stmt_expr_attributes)]
use std::ops::{Coroutine, CoroutineState};
use std::pin::pin;
fn main() {
// generators (i.e. yield doesn't return anything useful)
let mut gn = gen {
yield 1;
2.yield;
};
assert_eq!(gn.next(), Some(1));
assert_eq!(gn.next(), Some(2));
assert_eq!(gn.next(), None);
//coroutines (i.e. yield returns something useful)
let mut coro = pin!(
#[coroutine]
|_: i32| {
let x = 1.yield;
(x + 2).yield;
}
);
assert_eq!(coro.as_mut().resume(0), CoroutineState::Yielded(1));
assert_eq!(coro.as_mut().resume(2), CoroutineState::Yielded(4));
assert_eq!(coro.as_mut().resume(3), CoroutineState::Complete(()));
}