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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
commit | 218caa410aa38c29984be31a5229b9fa717560ee (patch) | |
tree | c54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/closures/supertrait-hint-cycle.rs | |
parent | Releasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/closures/supertrait-hint-cycle.rs')
-rw-r--r-- | tests/ui/closures/supertrait-hint-cycle.rs | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/tests/ui/closures/supertrait-hint-cycle.rs b/tests/ui/closures/supertrait-hint-cycle.rs new file mode 100644 index 000000000..dbb06b2ef --- /dev/null +++ b/tests/ui/closures/supertrait-hint-cycle.rs @@ -0,0 +1,65 @@ +// edition:2021 +// check-pass + +#![feature(type_alias_impl_trait)] +#![feature(closure_lifetime_binder)] + +use std::future::Future; + +trait AsyncFn<I, R>: FnMut(I) -> Self::Fut { + type Fut: Future<Output = R>; +} + +impl<F, I, R, Fut> AsyncFn<I, R> for F +where + Fut: Future<Output = R>, + F: FnMut(I) -> Fut, +{ + type Fut = Fut; +} + +async fn call<C, R, F>(mut ctx: C, mut f: F) -> Result<R, ()> +where + F: for<'a> AsyncFn<&'a mut C, Result<R, ()>>, +{ + loop { + match f(&mut ctx).await { + Ok(val) => return Ok(val), + Err(_) => continue, + } + } +} + +trait Cap<'a> {} +impl<T> Cap<'_> for T {} + +fn works(ctx: &mut usize) { + let mut inner = 0; + + type Ret<'a, 'b: 'a> = impl Future<Output = Result<usize, ()>> + 'a + Cap<'b>; + + let callback = for<'a, 'b> |c: &'a mut &'b mut usize| -> Ret<'a, 'b> { + inner += 1; + async move { + let _c = c; + Ok(1usize) + } + }; + call(ctx, callback); +} + +fn doesnt_work_but_should(ctx: &mut usize) { + let mut inner = 0; + + type Ret<'a, 'b: 'a> = impl Future<Output = Result<usize, ()>> + 'a + Cap<'b>; + + call(ctx, for<'a, 'b> |c: &'a mut &'b mut usize| -> Ret<'a, 'b> { + inner += 1; + async move { + let _c = c; + Ok(1usize) + } + }); +} + +fn main() {} |