tests/ui/underscore-lifetime/dyn-trait-underscore.stderr

   1 error: lifetime may not live long enough
   2   --> $DIR/dyn-trait-underscore.rs:8:5
   3    |
   4 LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T>> {
   5    |                - let's call the lifetime of this reference `'1`
   6 LL |     //                      ^^^^^^^^^^^^^^^^^^^^^ bound *here* defaults to `'static`
   7 LL |     Box::new(items.iter())
   8    |     ^^^^^^^^^^^^^^^^^^^^^^ returning this value requires that `'1` must outlive `'static`
   9    |
  10 help: to declare that the trait object captures data from argument `items`, you can add an explicit `'_` lifetime bound
  11    |
  12 LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T> + '_> {
  13    |                                                   ++++
  14
  15 error: aborting due to previous error
  16