[rustc.git] / src / test / ui / type-alias-impl-trait / issue-53598.rs

#![feature(type_alias_impl_trait)]

use std::fmt::Debug;

pub trait Foo {
    type Item: Debug;

    fn foo<T: Debug>(_: T) -> Self::Item;
}

#[derive(Debug)]
pub struct S<T>(std::marker::PhantomData<T>);

pub struct S2;

impl Foo for S2 {
    type Item = impl Debug;

    fn foo<T: Debug>(_: T) -> Self::Item {
        S::<T>(Default::default())
        //~^ Error type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
    }
}

fn main() {
    S2::foo(123);
}
Commit	Line	Data
94222f64	1	#![feature(type_alias_impl_trait)]
416331ca XL	2
	3	use std::fmt::Debug;
	4
	5	pub trait Foo {
	6	type Item: Debug;
	7
	8	fn foo<T: Debug>(_: T) -> Self::Item;
	9	}
	10
	11	#[derive(Debug)]
	12	pub struct S<T>(std::marker::PhantomData<T>);
	13
	14	pub struct S2;
	15
	16	impl Foo for S2 {
	17	type Item = impl Debug;
	18
	19	fn foo<T: Debug>(_: T) -> Self::Item {
416331ca	20	S::<T>(Default::default())
ee023bcb	21	//~^ Error type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
416331ca XL	22	}
	23	}
	24
	25	fn main() {
	26	S2::foo(123);
	27	}