E0596 should suggest changing type if it suggest taking taking mutable reference instead of just reference #106857
Description
Given the following code:
fn main() { let x: &[isize] = &[1, 2, 3, 4, 5]; // Can't mutably slice an immutable slice let _slice: &mut [isize] = &mut [0, 1]; let _ = &mut x[2..4]; //~ERROR cannot borrow `*x` as mutable, as it is behind a `&` reference }The current output is:
error[E0596]: cannot borrow `*x` as mutable, as it is behind a `&` reference --> src/lib.rs:5:18 | 5 | let _ = &mut x[2..4]; //~ERROR cannot borrow `*x` as mutable, as it is behind a `&` reference | ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable | help: consider changing this to be a mutable reference | 2 | let x: &[isize] = &mut [1, 2, 3, 4, 5]; | ~~~~~~~~~~~~~~~~~~~~ For more information about this error, try `rustc --explain E0596`. If we apply the suggestion this will cause the next problem, because &mut[1,2...] is not &[isize] but &mut [isize] 🙃
fn main() { let x: &[isize] = &mut [1, 2, 3, 4, 5]; // Can't mutably slice an immutable slice let _slice: &mut [isize] = &mut [0, 1]; let _ = &mut x[2..4]; //~ERROR cannot borrow `*x` as mutable, as it is behind a `&` reference }so we should suggest let x: &mut [isize] = &mut [1, 2, 3, 4, 5]; right away, if possible.