Function std::intrinsics::atomic_cxchgweak

pub unsafe extern "rust-intrinsic" fn atomic_cxchgweak<T>(
    dst: *mut T, 
    old: T, 
    src: T
) -> (T, bool) where
    T: Copy, 

🔬 This is a nightly-only experimental API. (core_intrinsics)

intrinsics are unlikely to ever be stabilized, instead they should be used through stabilized interfaces in the rest of the standard library

如果当前值与 old 值相同，则存储一个值。

通过将 Ordering::SeqCst 用作 success 和 failure 参数，可以通过 compare_exchange_weak 方法在 atomic 类型上使用此内联函数的稳定版本。

例如， AtomicBool::compare_exchange_weak.