src/test/ui/type-alias-impl-trait/generic_lifetime_param.rs

// build-pass (FIXME(62277): could be check-pass?)

#![feature(type_alias_impl_trait)]

fn main() {}

type Region<'a> = impl std::fmt::Debug;

fn region<'b>(a: &'b ()) -> Region<'b> {
    a
}