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//@ aux-build:block-on.rs
//@ edition:2021
//@ run-pass
//@ check-run-results
// Same as miri's `tests/pass/async-closure-captures.rs`, keep in sync
extern crate block_on;
fn main() {
block_on::block_on(async_main());
}
async fn call<T>(f: &impl AsyncFn() -> T) -> T {
f().await
}
async fn call_once<T>(f: impl AsyncFnOnce() -> T) -> T {
f().await
}
#[derive(Debug)]
#[allow(unused)]
struct Hello(i32);
async fn async_main() {
// Capture something by-ref
{
let x = Hello(0);
let c = async || {
println!("{x:?}");
};
call(&c).await;
call_once(c).await;
let x = &Hello(1);
let c = async || {
println!("{x:?}");
};
call(&c).await;
call_once(c).await;
}
// Capture something and consume it (force to `AsyncFnOnce`)
{
let x = Hello(2);
let c = async || {
println!("{x:?}");
drop(x);
};
call_once(c).await;
}
// Capture something with `move`, don't consume it
{
let x = Hello(3);
let c = async move || {
println!("{x:?}");
};
call(&c).await;
call_once(c).await;
let x = &Hello(4);
let c = async move || {
println!("{x:?}");
};
call(&c).await;
call_once(c).await;
}
// Capture something with `move`, also consume it (so `AsyncFnOnce`)
{
let x = Hello(5);
let c = async move || {
println!("{x:?}");
drop(x);
};
call_once(c).await;
}
fn force_fnonce<T>(f: impl AsyncFnOnce() -> T) -> impl AsyncFnOnce() -> T {
f
}
// Capture something with `move`, but infer to `AsyncFnOnce`
{
let x = Hello(6);
let c = force_fnonce(async move || {
println!("{x:?}");
});
call_once(c).await;
let x = &Hello(7);
let c = force_fnonce(async move || {
println!("{x:?}");
});
call_once(c).await;
}
// Capture something by-ref, but infer to `AsyncFnOnce`
{
let x = Hello(8);
let c = force_fnonce(async || {
println!("{x:?}");
});
call_once(c).await;
let x = &Hello(9);
let c = force_fnonce(async || {
println!("{x:?}");
});
call_once(c).await;
}
}
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