How Objective-C singleton should implement init method?

Question

I read a couple of amazing resources on singletons in Obj-C:

1. SO question: What does your Objective-C singleton look like?
2. Friday Q&A: Care and Fee

Answer 1

To make the init/new methods unavailable for callers of your singleton class you could use the NS_UNAVAILABLE macro in your header file:

- (id)init NS_UNAVAILABLE; 
+ (id)new NS_UNAVAILABLE; 

+ (instancetype)sharedInstance;