error[E0502]: cannot borrow `*ptr` as immutable because `ptr` is also borrowed as mutable --> $DIR/borrowck-closures-use-after-free.rs:32:9 | LL | let mut test = |foo: &Foo| { | ----------- mutable borrow occurs here LL | ptr = box Foo { x: ptr.x + 1 }; | --- previous borrow occurs due to use of `ptr` in closure LL | }; LL | test(&*ptr); //~ ERROR cannot borrow `*ptr` | ^^^^ immutable borrow occurs here LL | } | - mutable borrow ends here error: aborting due to previous error For more information about this error, try `rustc --explain E0502`.