CODEWITHSUNDEEP
swift
Luca Angeletti
Luca Angeletti

Reputation: 59496

Cannot call value of non-function type 'CIImage?'

This code does compile perfectly fine

let ciImage = CIImage(image:UIImage())

however when I move it into an extension of UIImage

extension UIImage {
    func foo() {
        let ciImage = CIImage(image:UIImage()) // compile error
    }
}

I get the following compile error

Cannot call value of non-function type 'CIImage?'

Why?

Tested with Xcode Playground 7.1.1. and Swift 2.1

Upvotes: 14

Views: 3334

Answers (1)

matt
matt

Reputation: 534925

It's because, once inside UIImage, the term CIImage is seen as the CIImage property of UIImage, due to implicit self as message recipient — in other words, Swift turns your CIImage into self.CIImage and it's all downhill from there.

You can solve this by disambiguating thru Swift's use of module namespacing:

extension UIImage {
    func foo() {
        let ciImage = UIKit.CIImage(image:UIImage())
    }
}

EDIT In Swift 3 this problem will go away, because all properties will start with small letters. The property will be named ciImage, and there will be no confusion with the CIImage class.

Upvotes: 37

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