Function std::intrinsics::atomic_xsub_rel

pub unsafe extern "rust-intrinsic" fn atomic_xsub_rel<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::Release as the order. For example, AtomicIsize::fetch_sub.