// This test should never pass! #![feature(type_alias_impl_trait)] trait Captures<'a> {} impl Captures<'_> for T {} struct MyTy<'a, 'b>(Option<*mut &'a &'b ()>); unsafe impl Send for MyTy<'_, 'static> {} fn step1<'a, 'b: 'a>() -> impl Sized + Captures<'b> + 'a { MyTy::<'a, 'b>(None) } mod tait { type Tait<'a> = impl Sized + 'a; pub(super) fn step2<'a, 'b: 'a>() -> Tait<'a> { super::step1::<'a, 'b>() //~^ ERROR hidden type for `Tait<'a>` captures lifetime that does not appear in bounds } } fn step3<'a, 'b: 'a>() -> impl Send + 'a { tait::step2::<'a, 'b>() // This should not be Send unless `'b: 'static` } fn main() {}