error[E0502]: cannot borrow `*ptr` as immutable because it is also borrowed as mutable --> $DIR/borrowck-closures-use-after-free.rs:22:8 | LL | let mut test = |foo: &Foo| { | ----------- mutable borrow occurs here LL | ptr = Box::new(Foo { x: ptr.x + 1 }); | --- first borrow occurs due to use of `ptr` in closure LL | }; LL | test(&*ptr); | ---- ^^^^^ immutable borrow occurs here | | | mutable borrow later used by call error: aborting due to previous error For more information about this error, try `rustc --explain E0502`.