File: issue-105536-const-val-roundtrip-ptr-eq.rs

package info (click to toggle)
rustc 1.88.0%2Bdfsg1-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 934,128 kB
  • sloc: xml: 158,127; python: 36,062; javascript: 19,855; sh: 19,700; cpp: 18,947; ansic: 12,993; asm: 4,792; makefile: 690; lisp: 29; perl: 29; ruby: 19; sql: 11
file content (31 lines) | stat: -rw-r--r-- 1,163 bytes parent folder | download | duplicates (15)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
//@ run-pass

// This does not reflect a stable guarantee (we guarantee very little for equality of pointers
// around `const`), but it would be good to understand what is happening if these assertions ever
// fail.
use std::ptr::NonNull;
use std::slice::from_raw_parts;

const PTR_U8: *const u8 = NonNull::dangling().as_ptr();
const CONST_U8_REF: &[u8] = unsafe { from_raw_parts(PTR_U8, 0) };
const CONST_U8_PTR: *const u8 = unsafe { from_raw_parts(PTR_U8, 0).as_ptr() };
static STATIC_U8_REF: &[u8] = unsafe { from_raw_parts(PTR_U8, 0) };

const PTR_U16: *const u16 = NonNull::dangling().as_ptr();
const CONST_U16_REF: &[u16] = unsafe { from_raw_parts(PTR_U16, 0) };

const fn const_u8_fn() -> &'static [u8] {
    unsafe { from_raw_parts(PTR_U8, 0) }
}

fn main() {
    let ptr_u8 = unsafe { from_raw_parts(PTR_U8, 0) }.as_ptr();
    let ptr_u16 = unsafe { from_raw_parts(PTR_U16, 0) }.as_ptr();

    assert_eq!(ptr_u8, PTR_U8);
    assert_eq!(ptr_u8, CONST_U8_PTR);
    assert_eq!(ptr_u8, const_u8_fn().as_ptr());
    assert_eq!(ptr_u8, STATIC_U8_REF.as_ptr());
    assert_eq!(ptr_u16, CONST_U16_REF.as_ptr());
    assert_eq!(ptr_u8, CONST_U8_REF.as_ptr());
}