error: lifetime may not live long enough
  --> $DIR/ex3-both-anon-regions-return-type-is-anon.rs:7:5
   |
LL |   fn foo<'a>(&self, x: &i32) -> &i32 {
   |              -         - let's call the lifetime of this reference `'1`
   |              |
   |              let's call the lifetime of this reference `'2`
LL |     x
   |     ^ associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
   |
help: consider introducing a named lifetime parameter and update trait if needed
   |
LL |   fn foo<'a>(&'a self, x: &'a i32) -> &i32 {
   |               ++           ++

error: aborting due to previous error