rust/src/test/run-pass/struct-order-of-eval-3.rs

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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// Checks that functional-record-update order-of-eval is as expected
// even when no Drop-implementations are involved.
use std::sync::atomic::{Ordering, AtomicUsize, ATOMIC_USIZE_INIT};
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 = ATOMIC_USIZE_INIT;
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);
}