mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-02 11:44:28 +00:00
20 lines
423 B
Rust
20 lines
423 B
Rust
#![feature(rustc_attrs)]
|
|
|
|
#[rustc_layout_scalar_valid_range_start(1)]
|
|
#[repr(transparent)]
|
|
pub(crate) struct NonZero<T>(pub(crate) T);
|
|
fn main() {}
|
|
|
|
const fn foo() -> NonZero<u32> {
|
|
let mut x = unsafe { NonZero(1) };
|
|
x.0 = 0;
|
|
//~^ ERROR mutation of layout constrained field is unsafe
|
|
x
|
|
}
|
|
|
|
const fn bar() -> NonZero<u32> {
|
|
let mut x = unsafe { NonZero(1) };
|
|
unsafe { x.0 = 0 }; // this is UB
|
|
x
|
|
}
|