How can I make Int conform to BinaryFloatingPoint or Double/CGFloat conform to BinaryInteger?

Question

I have a function which accept values which conform to Numeric protocol, in some point I want convert it to Int, Double or CGFloat.

the error from xCode:

Initializer 'init(_:)' requires that 'T' conform to 'BinaryInteger'

my function:

func test<T: Numeric>(value1: T, value2: T) {

    let someWork = value1 + value2

    let intValue: Int = Int(someWork)               // <<: Here!
    let doubleValue: Double = Double(someWork)      // <<: Here!
    let cgflotValue: CGFloat = CGFloat(someWork)    // <<: Here!

    print(intValue, doubleValue, cgflotValue)

}

then I saw the xCode error and updated my function to this down version, I put out Numeric because BinaryInteger and BinaryFloatingPoint conform to Numeric

func test<T: BinaryInteger & BinaryFloatingPoint>(value1: T, value2: T) {
   
    let someWork = value1 + value2
    
    let intValue: Int = Int(someWork)               // <<: Here: I add BinaryInteger because of Int
    let doubleValue: Double = Double(someWork)      // <<: Here: I add BinaryFloatingPoint because of Double
    let cgflotValue: CGFloat = CGFloat(someWork)    // <<: Here: I add BinaryFloatingPoint because of CGFloat
    
    print(intValue, doubleValue, cgflotValue)
    
}

use case:

let testValue1: Int = 2
test(value1: testValue1, value2: testValue1)

xCode error for use case:

Global function 'test(value1:value2:)' requires that 'Int' conform to 'BinaryFloatingPoint'

use case:

let testValue2: Double = 2.0
test(value1: testValue2, value2: testValue2)

xCode error for use case:

Global function 'test(value1:value2:)' requires that 'Double' conform to 'BinaryInteger'

How can I make Int conform to BinaryFloatingPoint?

Or:

How can I make Double/CGFloat conform to BinaryInteger?

as you see in xCode errors.

Possibly helpful: https://stackoverflow.com/a/53774667/1187415 — Martin R, Jul 09 '21 at 11:41
So judging by the accepted answer I guess that you never want to mix integers and floating point values as arguments to the function? — Joakim Danielson, Jul 09 '21 at 12:11
@JoakimDanielson: I never wanted to mix them, I wanted my function cover all kind of numbers. the errors forced me to add those protocols beside together. — ios coder, Jul 09 '21 at 12:23

score 3 · Accepted Answer · answered Jul 09 '21 at 11:29

You can add two same functions with different constraint

//T: BinaryInteger & BinaryFloatingPoint
func test<T>(value1: T, value2: T) where T: BinaryInteger{
    
    let someWork = value1 + value2
    
    let intValue: Int = Int(someWork)               // <<: Here: I add BinaryInteger because of Int
    let doubleValue: Double = Double(someWork)      // <<: Here: I add BinaryFloatingPoint because of Double
    let cgflotValue: CGFloat = CGFloat(someWork)    // <<: Here: I add BinaryFloatingPoint because of CGFloat
    
    print(intValue, doubleValue, cgflotValue)
    
}
func test<T>(value1: T, value2: T) where T: BinaryFloatingPoint{
    
    let someWork = value1 + value2
    
    let intValue: Int = Int(someWork)               // <<: Here: I add BinaryInteger because of Int
    let doubleValue: Double = Double(someWork)      // <<: Here: I add BinaryFloatingPoint because of Double
    let cgflotValue: CGFloat = CGFloat(someWork)    // <<: Here: I add BinaryFloatingPoint because of CGFloat
    
    print(intValue, doubleValue, cgflotValue)
    
}

score 0 · Answer 2 · answered Jul 09 '21 at 11:31

0

You can't. An integer cannot conform to BinaryFloatingPoint and a floating point number cannot conform to BinaryInteger, and you can't make them.

Your function test wants an argument that conforms to both. Int doesn't and Double doesn't.

answered Jul 09 '21 at 11:31

gnasher729

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How can I make Int conform to BinaryFloatingPoint or Double/CGFloat conform to BinaryInteger?

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