var body: some View {
var body: some View {
Eg. SquareButton and RoundButton are implementations of the Button (protocol).
You want to create a function that returns the button, but you don't want to specify to the user exactly what type of button is it (as it doesn't matter). Your function could just declare the top level protocol as the return type without needed to specify the word "some"
createPlayButton -> Button
instead of createPlayButton -> some Button
Am I missing something? It feels like the 'some' keyword is just there to help the compiler and not the users necessary
it seems like the equivalent of id <MyProtocol> in Objective-C. Basically just a surface re-arranging of names, but keeping the same concepts as in Objective-C
I feel Golang did better in this regards... (eg. not necessary distinguishing between protocols and super class-es, it is quacks like a duck, it is a duck)
The "some" keyword indicates that the function returns a specific type, even if that type isn't known to the caller.
One place where this is meaningful is if you have to use the result of that function in a generic function. For instance if my functions are defined like this:
func createPlayButton() -> Button { ... }
func doSomething<T: Button>(_ button: T) { ... }
doSomething(createPlayButton())
func createPlayButton() -> some Button { ... }
protocol P {
static var x: Int { get }
}
func f() -> some P { ... }
let p = f()
let x = type(of:p).x
https://docs.swift.org/swift-book/LanguageGuide/OpaqueTypes....