Controlling the lifetime

In our code, we have used an @autoclosure(escaping) attribute. It is a very powerful attribute and it deserves to be covered in detail. There is also an @noescape attribute. Let's explore them in more detail.

Applying the @autoclosure and @noescape attributes

First, let's have a look at when and how we could use these attributes. We can apply them to a function parameter with a function type. A function type can be represented as a method, function, or closure and it has (parameters) -> (return) notation. Here are a few examples:

func aFunc(f: () -> Void )
func increase(f: () -> Int ) -> Int
func multiply(f: (Int, Int) -> Int ) -> Int

@autoclosure

The @autoclosure attribute can be applied to a parameter with a function type that has no arguments and returns any type, () -> T. For example:

func check(@autoclosure condition: () -> Bool)
func increase(@autoclosure f: () -> Int ) -> Int

When we use an increase function without the @autoclosure...