4 fn foo(&self, _: &impl Debug);
8 fn foo<U: Debug>(&self, _: &U) { }
9 //~^ Error method `foo` has incompatible signature for trait
13 fn bar<U: Debug>(&self, _: &U);
17 fn bar(&self, _: &impl Debug) { }
18 //~^ Error method `bar` has incompatible signature for trait
21 // With non-local trait (#49841):
23 use std::hash::{Hash, Hasher};
28 fn hash(&self, hasher: &mut impl Hasher) {}
29 //~^ Error method `hash` has incompatible signature for trait