Array Extension

a.swift

extension CollectionType where Generator.Element == String {
    func find(subString:Generator.Element) -> Int {
        for (i,s) in self.enumerate() {
            if s.containsString(subString) {
                return i
            }
        }
        return -1
    }
}

extension CollectionType where Generator.Element == Int {
    func find(i:Generator.Element) -> Int {
        for n in self {
            if n == i {
                return n
            }
        }
        return -1
    }
}

let a = ["1222", "abdc", " anc abc", "abc abc", "123"]
let b = [1, 2, 3, 5, 5, 6, 9, 10]

a.find("abc")
b.find(11)