// check-pass use std::ops::Deref; // issue 89190 trait A {} trait B: A {} impl<'a> Deref for dyn 'a + B { //~^ WARN this `Deref` implementation is covered by an implicit supertrait coercion type Target = dyn A; fn deref(&self) -> &Self::Target { todo!() } } fn take_a(_: &dyn A) {} fn whoops(b: &dyn B) { take_a(b) } fn main() {}