Function std::intrinsics::atomic_xchg

pub unsafe extern "rust-intrinsic" fn atomic_xchg<T>(dst: *mut T, src: T) -> T 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

将值存储在指定的内存位置，并返回旧值。

通过将 Ordering::SeqCst 作为 order 传递，可以通过 swap 方法在 atomic 类型上使用此内联函数的稳定版本。 例如， AtomicBool::swap.