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#![feature(impl_trait_in_assoc_type)]
trait Foo: Sized {
type Bar;
type Gat<T: Foo>;
fn foo(self) -> (<Self as Foo>::Gat<u32>, <Self as Foo>::Gat<Self>);
}
impl Foo for u32 {
type Bar = ();
type Gat<T: Foo> = ();
fn foo(self) -> (<Self as Foo>::Gat<u32>, <Self as Foo>::Gat<Self>) {
((), ())
}
}
impl Foo for () {
type Bar = impl Sized;
//~^ ERROR: unconstrained opaque type
type Gat<T: Foo> = <T as Foo>::Bar;
// Because we encounter `Gat<u32>` first, we never walk into another `Gat`
// again, thus missing the opaque type that we could be defining.
fn foo(self) -> (<Self as Foo>::Gat<u32>, <Self as Foo>::Gat<Self>) {
((), ())
//~^ ERROR: mismatched types
}
}
fn main() {}
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