rust/tests/ui/structs-enums/struct-order-of-eval-3.rs

38 lines
939 B
Rust

//@ run-pass
// Checks that functional-record-update order-of-eval is as expected
// even when no Drop-implementations are involved.
use std::sync::atomic::{Ordering, AtomicUsize};
struct W { wrapped: u32 }
struct S { f0: W, _f1: i32 }
pub fn main() {
const VAL: u32 = 0x89AB_CDEF;
let w = W { wrapped: VAL };
let s = S {
f0: { event(0x01); W { wrapped: w.wrapped + 1 } },
..S {
f0: { event(0x02); w},
_f1: 23
}
};
assert_eq!(s.f0.wrapped, VAL + 1);
let actual = event_log();
let expect = 0x01_02;
assert!(expect == actual,
"expect: 0x{:x} actual: 0x{:x}", expect, actual);
}
static LOG: AtomicUsize = AtomicUsize::new(0);
fn event_log() -> usize {
LOG.load(Ordering::SeqCst)
}
fn event(tag: u8) {
let old_log = LOG.load(Ordering::SeqCst);
let new_log = (old_log << 8) + tag as usize;
LOG.store(new_log, Ordering::SeqCst);
}