# Function core::intrinsics::atomic_cxchgweak_failacq[−][src]

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

🔬 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 a value if the current value is the same as the `old` value.

The stabilized version of this intrinsic is available on the `atomic` types via the `compare_exchange_weak` method by passing `Ordering::SeqCst` as the `success` and `Ordering::Acquire` as the `failure` parameters. For example, `AtomicBool::compare_exchange_weak`.