error[E0502]: cannot borrow `x` as immutable because it is also borrowed as mutable
  --> $DIR/method-self-arg-2.rs:15:14
   |
LL |     let y = &mut x;
   |             ------ mutable borrow occurs here
LL |     Foo::bar(&x);
   |              ^^ immutable borrow occurs here
LL |     y.use_mut();
   |     ----------- mutable borrow later used here

error[E0499]: cannot borrow `x` as mutable more than once at a time
  --> $DIR/method-self-arg-2.rs:20:14
   |
LL |     let y = &mut x;
   |             ------ first mutable borrow occurs here
LL |     Foo::baz(&mut x);
   |              ^^^^^^ second mutable borrow occurs here
LL |     y.use_mut();
   |     ----------- first borrow later used here

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0499, E0502.
For more information about an error, try `rustc --explain E0499`.