error: lifetime may not live long enough
  --> $DIR/E0490.rs:2:12
   |
LL | fn f<'a, 'b>(y: &'b ()) {
   |      --  -- lifetime `'b` defined here
   |      |
   |      lifetime `'a` defined here
LL |     let x: &'a _ = &y;
   |            ^^^^^ type annotation requires that `'b` must outlive `'a`
   |
   = help: consider adding the following bound: `'b: 'a`

error[E0597]: `y` does not live long enough
  --> $DIR/E0490.rs:2:20
   |
LL | fn f<'a, 'b>(y: &'b ()) {
   |      -- lifetime `'a` defined here
LL |     let x: &'a _ = &y;
   |            -----   ^^ borrowed value does not live long enough
   |            |
   |            type annotation requires that `y` is borrowed for `'a`
...
LL | }
   |  - `y` dropped here while still borrowed

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0597`.
