1 error: unsatisfied lifetime constraints
2 --> $DIR/match-ref-mut-let-invariance.rs:21:9
5 | -- lifetime `'b` defined here
6 LL | fn bar<'a>(&'a mut self) -> &'a mut &'a i32 {
7 | -- lifetime `'a` defined here
8 LL | let ref mut x = self.0;
9 LL | x //~ ERROR mismatched types
10 | ^ returning this value requires that `'a` must outlive `'b`
12 error: aborting due to previous error