Rust: can a struct hold a borrowed reference to its owner?

test.rs

struct Foo {
  bar: ~Bar
  //    ^~~ error: Illegal anonymous lifetime: anonymous lifetimes are not permitted here
}
struct Bar<'self> {
  owner: &'self Foo
  //            ^~~ error: Illegal anonymous lifetime: anonymous lifetimes are not permitted here
}

// Note that if Bar has _any_ borrowed reference (not just to a Foo),
// compiler will complain about illegal anonymous lifetime.