CODEWITHSUNDEEP
swiftoverloading
RobertJoseph
RobertJoseph

Reputation: 8158

How to disambiguate overloaded functions

This is a totally contrived example I wrote while learning about function overloading in Swift. The following functions differ only in return type (the first function implicitly returns Void / () while the other returns Int).

func foo(x:Int, y:Int) {
}

func foo(x:Int, y:Int) -> Int {
  return 0
}

// Call the version which returns Int
let i: Int = foo(6, y: 7)

// Call the version which returns Void
let v: Void = foo(6, y: 7)

// Ambiguous
foo(6, y:7)  // How can I force a call to the Void version without using let/var?

// I thought this might work but doesn't
foo(6,y: 7) as (Int, Int) -> Void

Is there a way I can call the Void version without using let, i.e. some type of cast? Again, I realize this is a contrived example but I'd like to understand the options here.

Upvotes: 4

Views: 318

Answers (1)

vacawama
vacawama

Reputation: 154583

You can disambiguate the two foo functions by casting the result:

foo(6, y: 7) as Int

foo(6, y: 7) as Void

or you can cast foo itself:

(foo as (Int, y: Int) -> Int)(6, y: 7)

(foo as (Int, y: Int) -> Void)(6, y: 7)

Note: () may be used in place of Void in both instances.

Upvotes: 6

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