#![feature(rustc_attrs)] #[rustc_layout_scalar_valid_range_start(1)] #[repr(transparent)] pub(crate) struct NonZero(pub(crate) T); fn main() {} const fn foo() -> NonZero { NonZero(0) } //~^ ERROR initializing type with `rustc_layout_scalar_valid_range` attr is unsafe const fn bar() -> NonZero { unsafe { NonZero(0) } }