error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates
  --> $DIR/assoc-type-lifetime-unconstrained.rs:17:6
   |
LL | impl<'a, I> UnwrapItemsExt for I {
   |      ^^ unconstrained lifetime parameter

error[E0792]: expected generic lifetime parameter, found `'_`
  --> $DIR/assoc-type-lifetime-unconstrained.rs:22:9
   |
LL | impl<'a, I> UnwrapItemsExt for I {
   |      -- this generic parameter must be used with a generic lifetime parameter
...
LL |         MyStruct {}
   |         ^^^^^^^^^^^

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0207, E0792.
For more information about an error, try `rustc --explain E0207`.