// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty // revisions: current next #![feature(return_position_impl_trait_in_trait)] #![allow(incomplete_features)] struct U; trait Foo { fn bar(&self) -> impl Sized; } impl Foo for U { fn bar(&self) {} //~^ ERROR method `bar` has 1 type parameter but its trait declaration has 0 type parameters } fn main() { U.bar(); }