error: lifetime may not live long enough
  --> $DIR/where_clauses_in_structs.rs:13:11
   |
LL | fn bar<'a, 'b>(x: Cell<&'a u32>, y: Cell<&'b u32>) {
   |        --  -- lifetime `'b` defined here
   |        |
   |        lifetime `'a` defined here
LL |     Foo { x, y };
   |           ^ this usage requires that `'a` must outlive `'b`
   |
   = help: consider adding the following bound: `'a: 'b`
   = note: requirement occurs because of the type Cell<&u32>, which makes the generic argument &u32 invariant
   = note: the struct Cell<T> is invariant over the parameter T
   = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance

error: aborting due to previous error