[rustc.git] / src / test / ui / traits / trait-object-with-self-in-projection-output-good.rs

// build-pass (FIXME(62277): could be check-pass?)

// Regression test related to #56288. Check that a supertrait projection (of
// `Output`) that references `Self` can be ok if it is referencing a projection (of
// `Self::Target`, in this case). Note that we still require the user to manually
// specify both `Target` and `Output` for now.

trait Base {
    type Output;
}

trait Helper: Base<Output=<Self as Helper>::Target> {
    type Target;
}

impl Base for u32
{
    type Output = i32;
}

impl Helper for u32
{
    type Target = i32;
}

fn main() {
    let _x: Box<dyn Helper<Target=i32, Output=i32>> = Box::new(2u32);
}
Commit	Line	Data
416331ca	1	// build-pass (FIXME(62277): could be check-pass?)
69743fb6 XL	2
	3	// Regression test related to #56288. Check that a supertrait projection (of
	4	// `Output`) that references `Self` can be ok if it is referencing a projection (of
	5	// `Self::Target`, in this case). Note that we still require the user to manually
	6	// specify both `Target` and `Output` for now.
	7
	8	trait Base {
	9	type Output;
	10	}
	11
	12	trait Helper: Base<Output=<Self as Helper>::Target> {
	13	type Target;
	14	}
	15
	16	impl Base for u32
	17	{
	18	type Output = i32;
	19	}
	20
	21	impl Helper for u32
	22	{
	23	type Target = i32;
	24	}
	25
	26	fn main() {
	27	let _x: Box<dyn Helper<Target=i32, Output=i32>> = Box::new(2u32);
	28	}