#![feature(rustc_attrs, const_transmute)] #![allow(const_err)] // make sure we cannot allow away the errors tested here use std::mem; use std::ptr::NonNull; use std::num::{NonZeroU8, NonZeroUsize}; const NULL_PTR: NonNull = unsafe { mem::transmute(0usize) }; //~^ ERROR it is undefined behavior to use this value const NULL_U8: NonZeroU8 = unsafe { mem::transmute(0u8) }; //~^ ERROR it is undefined behavior to use this value const NULL_USIZE: NonZeroUsize = unsafe { mem::transmute(0usize) }; //~^ ERROR it is undefined behavior to use this value union Transmute { uninit: (), out: NonZeroU8, } const UNINIT: NonZeroU8 = unsafe { Transmute { uninit: () }.out }; //~^ ERROR it is undefined behavior to use this value // Also test other uses of rustc_layout_scalar_valid_range_start #[rustc_layout_scalar_valid_range_start(10)] #[rustc_layout_scalar_valid_range_end(30)] struct RestrictedRange1(u32); const BAD_RANGE1: RestrictedRange1 = unsafe { RestrictedRange1(42) }; //~^ ERROR it is undefined behavior to use this value #[rustc_layout_scalar_valid_range_start(30)] #[rustc_layout_scalar_valid_range_end(10)] struct RestrictedRange2(u32); const BAD_RANGE2: RestrictedRange2 = unsafe { RestrictedRange2(20) }; //~^ ERROR it is undefined behavior to use this value fn main() {}