Swift 3 - How to write functions with no initialisers like the new UIColors?

Question

In previous versions of swift, you would get the colour white like this UIColor.whiteColor()

However, in Swift 3, you get the colour white without initi

Answer 1

When the compiler can infer the type of the value you are going to need, like here

let a: Foo = ...

you can use a static member (method, function, stored property, computed property) omitting the name of the type.

So given this type

class Foo {
    static let a = Foo()
    static var b = Foo()
    static var c:Foo { return Foo() }
    static func d() -> Foo { return Foo() }
}

you can write

let a: Foo = .a
let b: Foo = .b
let c: Foo = .c
let d: Foo = .d()

The same technique can be used when you pass a value to a function

func doNothing(foo: Foo) { }

Again the type of the parameter can be inferred by the compiler so instead of writing

doNothing(foo: Foo.a)

you can simply write

doNothing(foo: .a)