Function std::intrinsics::atomic_xsub

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

Subtract from the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_sub method by passing Ordering::SeqCst as the order. For example, AtomicIsize::fetch_sub.