// run-pass #![feature(ptr_internals, test)] extern crate test; use test::black_box as b; // prevent promotion of the argument and const-propagation of the result use std::ptr::NonNull; const DANGLING: NonNull<u32> = NonNull::dangling(); const CASTED: NonNull<u32> = NonNull::cast(NonNull::<i32>::dangling()); pub fn main() { // Be super-extra paranoid and cast the fn items to fn pointers before blackboxing them. assert_eq!(DANGLING, b::<fn() -> _>(NonNull::dangling)()); assert_eq!(CASTED, b::<fn() -> _>(NonNull::dangling)()); }