1 error[E0502]: cannot borrow `this.x` as mutable because it is also borrowed as immutable
2 --> $DIR/borrowck-closures-unique-imm.rs:11:9
5 | ------- immutable borrow occurs here
7 | ^^^^^^^^^^^ mutable borrow occurs here
9 | ----------- immutable borrow later used here
11 error: aborting due to previous error
13 For more information about this error, try `rustc --explain E0502`.