Open Radar

 
Summary:
Using functions like sin, cos, sqrt and abs in Swift with CGFloats requires way too much typecasting.

Steps to Reproduce:
import UIKit

func distance(p1: CGPoint, p2: CGPoint) -> CGFloat {
    return sqrt(pow(p1.x - p2.x, 2) + pow(p1.y - p2.y, 2))
}

Expected Results:
Should return the distance between the two points. Works fine in a playground, but give the following error in compiled code:

  'NSNumber' is not a subtype of 'CGFloat'

If you wrap the result in a CGFloat cast, the error changes to:

  Could not find an overload for '+' that accepts the supplied arguments

So let's try overflowing addition/subtraction:

  Could not find an overload for 'init' that accepts the supplied arguments

Let's try removing the CGFloat cast:

  Cannot convert the expression's type 'CDouble' to type 'CDouble'

?!

Here's what finally worked:

func distance(p1: CGPoint, p2: CGPoint) -> CGFloat {
    return CGFloat(sqrt(pow(CDouble(p1.x - p2.x), 2) + pow(CDouble(p1.y - p2.y), 2)))
}


Actual Results:
Ideally the original writing should work not just in playgrounds, but also in compiled code:

func distance(p1: CGPoint, p2: CGPoint) -> CGFloat {
    return sqrt(pow(p1.x - p2.x, 2) + pow(p1.y - p2.y, 2))
}

There probably needs to be a standard Swift math library that adds trig functions that take native Float and Double types and return the same, or perhaps take any numeric type using generics.  

Version:
Xcode 6 Beta 2

Notes:


Configuration:


Attachments: