Uppercase all contacts family names

Contacts.swift

// A Twitter guy requested a way to update all his contacts family names to be uppercased
// So, I wanted to give a try to the all new iOS 9 Contacts framework

// I'm a Swift noob, I didn't even finish reading the Swift book (I'm at p. 302 :D)

import Contacts

let store = CNContactStore()
		
store.requestAccessForEntityType(.Contacts) { success, formerError  in
	if success
	{
		dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0)) {
			let predicate = CNContact.predicateForContactsInContainerWithIdentifier(store.defaultContainerIdentifier())
			let keysToFetch = [CNContactGivenNameKey, CNContactFamilyNameKey]

			do {
				let contacts = try store.unifiedContactsMatchingPredicate(predicate, keysToFetch: keysToFetch)
		
				let saveRequest = CNSaveRequest()
	
				for contact in contacts {
					if (contact.isKeyAvailable(CNContactFamilyNameKey)) {
						let updatedContact: CNMutableContact = contact.mutableCopy() as! CNMutableContact
						updatedContact.familyName = contact.familyName.uppercaseString

						saveRequest.updateContact(updatedContact)
					}
				}

				try store.executeSaveRequest(saveRequest)
			} catch _ {
				print("An error occured.")
			}
		}
	}
	else
	{
		if let error = formerError {
			print(error.localizedDescription)
		}
	}
}

Thanks, mate. Where you able to find a way to get all the contacts? With this one just a few came (which is better from all the posts I've seen in the past hour)

@fgringo: Sorry for taking so long to answer (I didn't receive any notification...), anyway...
It worked perfectly for me : I do get all the contacts if I put this snippet inside a simple application.
Maybe you have a very specific way to handle the contacts with your phone. Try looking at the CNContactStore and CNContainer documentation !