Function std::intrinsics::atomic_xchg_relaxed

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

🔬 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

Stores the value at the specified memory location, returning the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the swap method by passing Ordering::Relaxed as the order. For example, AtomicBool::swap.