return __sync_val_compare_and_swap(ptr, old_value, new_value);
#elif defined(_MSC_VER)
return InterlockedCompareExchange(ptr, new_value, old_value);
return __sync_val_compare_and_swap(ptr, old_value, new_value);
#elif defined(_MSC_VER)
return InterlockedCompareExchange(ptr, new_value, old_value);