rust/tests/ui/traits/next-solver/env-shadows-impls/discard-impls-shadowed-by-e...

31 lines
772 B
Rust

//@ compile-flags: -Znext-solver
//@ check-pass
// Normalizing `<T as Trait>::TraitAssoc` in the elaborated environment
// `[T: Trait, T: Super, <T as Super>::SuperAssoc = <T as Trait>::TraitAssoc]`
// has a single impl candidate, which uses the environment to
// normalize `<T as Trait>::TraitAssoc` to itself. We avoid this overflow
// by discarding impl candidates the trait bound is proven by a where-clause.
// https://github.com/rust-lang/trait-system-refactor-initiative/issues/76
trait Super {
type SuperAssoc;
}
trait Trait: Super<SuperAssoc = Self::TraitAssoc> {
type TraitAssoc;
}
impl<T, U> Trait for T
where
T: Super<SuperAssoc = U>,
{
type TraitAssoc = U;
}
fn overflow<T: Trait>() {
let x: <T as Trait>::TraitAssoc;
}
fn main() {}