error[E0596]: cannot borrow `x[..]` as mutable, as `x` is not declared as mutable --> $DIR/array_subslice.rs:7:21 | LL | pub fn subslice_array(x: [u8; 3]) { | - help: consider changing this to be mutable: `mut x` ... LL | let [ref y, ref mut z @ ..] = x; | ^^^^^^^^^ cannot borrow as mutable error[E0596]: cannot borrow `f` as mutable, as it is not declared as mutable --> $DIR/array_subslice.rs:10:5 | LL | let [ref y, ref mut z @ ..] = x; | - calling `f` requires mutable binding due to mutable borrow of `x` ... LL | f(); | ^ cannot borrow as mutable | help: consider changing this to be mutable | LL | let mut f = || { | +++ error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0596`.