| //@ compile-flags: -Znext-solver |
| #![feature(rustc_attrs)] |
| |
| // A test showcasing that the solver may need to |
| // compute a goal which is already in the provisional |
| // cache. |
| // |
| // However, given that `(): BInd` and `(): B` are currently distinct |
| // goals, this is actually not possible right now. |
| // |
| // FIXME(-Znext-solver=coinductive): With the new coinduction approach |
| // the same goal stack can be both inductive and coinductive, depending |
| // on why we're proving a specific nested goal. Rewrite this test |
| // at that point. |
| |
| #[rustc_coinductive] |
| trait A {} |
| |
| #[rustc_coinductive] |
| trait B {} |
| trait BInd {} |
| impl<T: ?Sized + B> BInd for T {} |
| |
| impl<T: ?Sized + BInd + B> A for T {} |
| impl<T: ?Sized + BInd> B for T {} |
| |
| fn impls_a<T: A>() {} |
| |
| fn main() { |
| impls_a::<()>(); |
| //~^ ERROR overflow evaluating the requirement `(): A` |
| } |
