error: lifetime may not live long enough
  --> $DIR/ret-impl-trait-one.rs:10:85
   |
LL |   async fn async_ret_impl_trait3<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a> + 'b {
   |  ________________________________--__--_______________________________________________^
   | |                                |   |
   | |                                |   lifetime `'b` defined here
   | |                                lifetime `'a` defined here
LL | |
LL | |     (a, b)
LL | | }
   | |_^ function was supposed to return data with lifetime `'b` but it is returning data with lifetime `'a`
   |
   = help: consider adding the following bound: `'a: 'b`

error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds
  --> $DIR/ret-impl-trait-one.rs:16:65
   |
LL | async fn async_ret_impl_trait1<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a> {
   |                                                                 ^^^^^^^^^^^^^^
   |
note: hidden type `(&'a u8, &'<empty> u8)` captures lifetime smaller than the function body
  --> $DIR/ret-impl-trait-one.rs:16:65
   |
LL | async fn async_ret_impl_trait1<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a> {
   |                                                                 ^^^^^^^^^^^^^^

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0700`.