| //@ known-bug: #107975 |
| //@ compile-flags: -Copt-level=2 |
| //@ run-pass |
| |
| // Derived from https://github.com/rust-lang/rust/issues/107975#issuecomment-1431758601 |
| |
| use std::ptr; |
| |
| fn main() { |
| let a: usize = { |
| let v = 0u8; |
| ptr::from_ref(&v).expose_provenance() |
| }; |
| let b: usize = { |
| let v = 0u8; |
| ptr::from_ref(&v).expose_provenance() |
| }; |
| |
| // So, are `a` and `b` equal? |
| |
| // Let's check their difference. |
| let i: usize = a - b; |
| // It's not zero, which means `a` and `b` are not equal. |
| assert_ne!(i, 0); |
| // But it looks like zero... |
| assert_eq!(i.to_string(), "0"); |
| // ...and now it *is* zero? |
| assert_eq!(i, 0); |
| // So `a` and `b` are equal after all? |
| } |
