tests/ui/impl-trait/deduce-signature-from-supertrait.rs

//@ check-pass

#![feature(type_alias_impl_trait)]

trait SuperExpectation: Fn(i32) {}

impl<T: Fn(i32)> SuperExpectation for T {}

type Foo = impl SuperExpectation;

#[define_opaque(Foo)]
fn bop() {
    let _: Foo = |x| {
        let _ = x.to_string();
    };
}

fn main() {}