This is a simple binary search algorithm implemented in Swift 2

binsearch.swift

func binarySearch(list: [Int], value: Int) -> Int {
    
    let count = list.count
    var min: Int = 0
    var max: Int = count
    var mid: Int = Int(round(Double(max / 2)))
    
    while(list[mid] != value) {
        if (list[mid] > value) {
            max = mid
            mid = Int(round(Double((max - min) / 2 + min)))
        } else {
            min = mid
            mid = Int(round(Double((max - min) / 2 + min)))
        }
    }
    return mid
}