// compile-flags: -Ztrait-solver=next

// check that a `alias-eq(<?a as TraitB>::Assoc, <?b as TraitB>::Assoc)` goal fails
// during coherence. We must not incorrectly constrain `?a` and `?b` to be
// equal.

trait TraitB {
    type Assoc;
}

trait Overlaps<T> {}

impl<T: TraitB> Overlaps<Box<T>> for <T as TraitB>::Assoc {}
impl<U: TraitB> Overlaps<U> for <U as TraitB>::Assoc {}
//~^ ERROR conflicting implementations of trait

fn main() {}