error[E0277]: can't compare `&i32` with `Bar<'b, 'static>`
  --> $DIR/self-referential-4.rs:7:31
   |
LL | fn bar<'a, 'b>(i: &'a i32) -> Bar<'a, 'b> {
   |                               ^^^^^^^^^^^ no implementation for `&i32 == Bar<'b, 'static>`
LL |     i
   |     - return type was inferred to be `&i32` here
   |
   = help: the trait `PartialEq<Bar<'b, 'static>>` is not implemented for `&i32`
   = help: the trait `PartialEq` is implemented for `i32`

error[E0277]: can't compare `&i32` with `Foo<'static, 'b>`
  --> $DIR/self-referential-4.rs:13:31
   |
LL | fn foo<'a, 'b>(i: &'a i32) -> Foo<'a, 'b> {
   |                               ^^^^^^^^^^^ no implementation for `&i32 == Foo<'static, 'b>`
LL |     i
   |     - return type was inferred to be `&i32` here
   |
   = help: the trait `PartialEq<Foo<'static, 'b>>` is not implemented for `&i32`
   = help: the trait `PartialEq` is implemented for `i32`

error[E0277]: can't compare `&i32` with `Moo<'static, 'a>`
  --> $DIR/self-referential-4.rs:19:31
   |
LL | fn moo<'a, 'b>(i: &'a i32) -> Moo<'a, 'b> {
   |                               ^^^^^^^^^^^ no implementation for `&i32 == Moo<'static, 'a>`
LL |     i
   |     - return type was inferred to be `&i32` here
   |
   = help: the trait `PartialEq<Moo<'static, 'a>>` is not implemented for `&i32`
   = help: the trait `PartialEq` is implemented for `i32`

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0277`.