Any way to get Int value of HKQueryAnchor?

I would also like to know how to use the new HKQueryAnchor object? Should we persist it somehow or is there another option for retrieving data without persisting it?

HKQueryAnchor(fromValue: Int(HKAnchoredObjectQueryNoAnchor))

Did anyone manage to solve how to persist this?

HKQueryAnchor implements NSSecureCoding, so it should be possible to persist this as NSData via a call to NSKeyedArchiver.archivedDataWithRootObject and then using a NSKeyedUnarchiver instance on which you would call decodeObjectOfClass. The problem that I've experienced is that the result from an unarchive call does not appear to be equal to the original value.

This is the way I wound up doing it. I'm saving it in a text file in the documents directory. Not the prettiest solution (I much preferred being able to persist it as an Int, though I'm sure Apple has their reasons for not allowing it), but it works.

For those who are curious, the code I settled on looks like this:

+ (nullable HKQueryAnchor *)hkAnchor {
    NSURL *url = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
    NSString *filePath = [url.path stringByAppendingPathComponent:@"hkAnchor.txt"];
    HKQueryAnchor *anchor = [NSKeyedUnarchiver unarchiveObjectWithFile:filePath];
    return anchor;
}
+ (void)setHKAnchor:(HKQueryAnchor *)anchor {
    NSURL *url = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
    NSString *filePath = [url.path stringByAppendingPathComponent:@"hkAnchor.txt"];
    [NSKeyedArchiver archiveRootObject:anchor toFile:filePath];
}

Thanks for the help, and best of luck.