error[E0491]: in type `&'b &'a usize`, reference has a longer lifetime than the data it references
  --> $DIR/regions-free-region-ordering-caller.rs:16:12
   |
LL |     let z: Option<&'b &'a usize> = None;
   |            ^^^^^^^^^^^^^^^^^^^^^
   |
note: the pointer is valid for the lifetime `'b` as defined here
  --> $DIR/regions-free-region-ordering-caller.rs:15:14
   |
LL | fn call2<'a, 'b>(a: &'a usize, b: &'b usize) {
   |              ^^
note: but the referenced data is only valid for the lifetime `'a` as defined here
  --> $DIR/regions-free-region-ordering-caller.rs:15:10
   |
LL | fn call2<'a, 'b>(a: &'a usize, b: &'b usize) {
   |          ^^

error[E0491]: in type `&'b Paramd<'a>`, reference has a longer lifetime than the data it references
  --> $DIR/regions-free-region-ordering-caller.rs:22:12
   |
LL |     let z: Option<&'b Paramd<'a>> = None;
   |            ^^^^^^^^^^^^^^^^^^^^^^
   |
note: the pointer is valid for the lifetime `'b` as defined here
  --> $DIR/regions-free-region-ordering-caller.rs:20:14
   |
LL | fn call3<'a, 'b>(a: &'a usize, b: &'b usize) {
   |              ^^
note: but the referenced data is only valid for the lifetime `'a` as defined here
  --> $DIR/regions-free-region-ordering-caller.rs:20:10
   |
LL | fn call3<'a, 'b>(a: &'a usize, b: &'b usize) {
   |          ^^

error[E0491]: in type `&'a &'b usize`, reference has a longer lifetime than the data it references
  --> $DIR/regions-free-region-ordering-caller.rs:27:12
   |
LL |     let z: Option<&'a &'b usize> = None;
   |            ^^^^^^^^^^^^^^^^^^^^^
   |
note: the pointer is valid for the lifetime `'a` as defined here
  --> $DIR/regions-free-region-ordering-caller.rs:26:10
   |
LL | fn call4<'a, 'b>(a: &'a usize, b: &'b usize) {
   |          ^^
note: but the referenced data is only valid for the lifetime `'b` as defined here
  --> $DIR/regions-free-region-ordering-caller.rs:26:14
   |
LL | fn call4<'a, 'b>(a: &'a usize, b: &'b usize) {
   |              ^^

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0491`.