Open Radar

 
Summary:
When calling the sort function on a Swift array, the app will crash if that sort function has protocol types as its parameters.

Steps to Reproduce:
Run the following code:

protocol ObjectWithInt {
    var i: Int {get}
}
class IntObject: NSObject, ObjectWithInt {
    let i: Int
    init(i: Int) {
        self.i = i
    }
}

var ints = [IntObject(i: 2), IntObject(i: 1), IntObject(i: 3)]
func sortIntsObjects(i1: ObjectWithInt, i2: ObjectWithInt) -> Bool {
    return i1.i < i2.i
}
ints.sort(sortIntsObjects) // this crashes

Version:
Xcode 6.1