21 lines
502 B
Rust
21 lines
502 B
Rust
|
#![feature(const_ptr_is_null)]
|
||
|
|
use std::ptr;
|
||
|
|
|
||
|
|
const IS_NULL: () = {
|
||
|
|
assert!(ptr::null::<u8>().is_null());
|
||
|
|
};
|
||
|
|
const IS_NOT_NULL: () = {
|
||
|
|
assert!(!ptr::null::<u8>().wrapping_add(1).is_null());
|
||
|
|
};
|
||
|
|
|
||
|
|
const MAYBE_NULL: () = {
|
||
|
|
let x = 15;
|
||
|
|
let ptr = &x as *const i32;
|
||
|
|
// This one is still unambiguous...
|
||
|
|
assert!(!ptr.is_null());
|
||
|
|
// but once we shift outside the allocation, we might become null.
|
||
|
|
assert!(!ptr.wrapping_sub(512).is_null()); //~inside `MAYBE_NULL`
|
||
|
|
};
|
||
|
|
|
||
|
|
fn main() {}
|