iOS Can someone explain some syntax to me please? <UITouch *>

[chrono1081]

Hi guys,

I noticed Xcode now corrects -

(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

to

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

I have never seen the <UITouch *> part before in Objective-C. Can anyone explain what exactly that syntax is doing? It seems to work fine without it but I'd like to know what it is. Searching didn't bring up anything on the topic.

 

[PhoneyDeveloper]

It's called 'objective c generics' It allows classes, usually container classes, to be specialized for a type other than id.

The <sometype*> syntax is common among a number of programming languages, like swift, Java, C++ and others.

 

[chrono1081]

It's called 'objective c generics' It allows classes, usually container classes, to be specialized for a type other than id.

The <sometype*> syntax is common among a number of programming languages, like swift, Java, C++ and others.

Thanks! I've seen it in C++ but never in Objective-C and thought maybe that's what it was, but I couldn't find an answer on it.