error[E0723]: mutable references in const fn are unstable --> $DIR/ranged_ints2_const.rs:11:9 | LL | let y = &mut x.0; | ^ | = note: see issue #57563 for more information = help: add `#![feature(const_fn)]` to the crate attributes to enable error[E0723]: mutable references in const fn are unstable --> $DIR/ranged_ints2_const.rs:18:9 | LL | let y = unsafe { &mut x.0 }; | ^ | = note: see issue #57563 for more information = help: add `#![feature(const_fn)]` to the crate attributes to enable error[E0133]: mutation of layout constrained field is unsafe and requires unsafe function or block --> $DIR/ranged_ints2_const.rs:11:13 | LL | let y = &mut x.0; | ^^^^^^^^ mutation of layout constrained field | = note: mutating layout constrained fields cannot statically be checked for valid values error: aborting due to 3 previous errors Some errors have detailed explanations: E0133, E0723. For more information about an error, try `rustc --explain E0133`.