| #![feature(rustc_attrs)] | |
| use std::cell::Cell; | |
| #[rustc_layout_scalar_valid_range_start(1)] | |
| #[repr(transparent)] | |
| pub(crate) struct NonZero<T>(pub(crate) T); | |
| fn main() { | |
| let mut x = unsafe { NonZero(Cell::new(1)) }; | |
| match x { | |
| NonZero(ref x) => { x } | |
| //~^ ERROR borrow of layout constrained field with interior mutability | |
| }; | |
| let mut y = unsafe { NonZero(42) }; | |
| match y { NonZero(ref y) => { y } }; // OK, type of `y` is freeze | |
| match y { NonZero(ref mut y) => { y } }; | |
| //~^ ERROR mutation of layout constrained field | |
| } |