1 // revisions: mirunsafeck thirunsafeck
2 // [thirunsafeck]compile-flags: -Z thir-unsafeck
4 #![feature(rustc_attrs)]
8 #[rustc_layout_scalar_valid_range_start(1)]
10 pub(crate) struct NonZero<T>(pub(crate) T);
12 let mut x = unsafe { NonZero(Cell::new(1)) };
14 NonZero(ref x) => { x }
15 //~^ ERROR borrow of layout constrained field with interior mutability
18 let mut y = unsafe { NonZero(42) };
19 match y { NonZero(ref y) => { y } }; // OK, type of `y` is freeze
20 match y { NonZero(ref mut y) => { y } };
21 //~^ ERROR mutation of layout constrained field