| //@ revisions: current next |
| //@[next] compile-flags: -Znext-solver |
| //@ ignore-compare-mode-next-solver (explicit revisions) |
| //@ check-pass |
| #![allow(unconditional_recursion)] |
| |
| // Regression test for trait-system-refactor-initiative#182. |
| |
| trait Id { |
| type This; |
| } |
| impl<T> Id for T { |
| type This = T; |
| } |
| fn to_assoc<T>(x: T) -> <T as Id>::This { |
| x |
| } |
| |
| fn mirror<T>(x: Vec<T>) -> impl Id<This = Vec<T>> { |
| let x = to_assoc(mirror(x)); |
| // `?x` equals `<opaque::<T> as Id>::This`. We need to eagerly infer the |
| // type of `?x` to prevent this method call from resulting in an error. |
| // |
| // We could use both the item bound to normalize to `Vec<T>`, or the |
| // blanket impl to normalize to `opaque::<T>`. We have to go with the |
| // item bound. |
| x.len(); |
| x |
| } |
| fn main() {} |
