ログメソッド
func LOG(message:String = "", file:String = __FILE__, funcName:String = __FUNCTION__, line:Int = __LINE__) {
    #if DEBUG
        var f:String = file.componentsSeparatedByString("/").last!
        var cnt:Int = 45 - f.utf16Count
        while 0 < cnt {
            f += " "
            cnt--
        }
        var sline:String = String(line)
        cnt = 4 - sline.utf16Count
        while 0 < cnt {
            sline = " "+sline
            cnt--
        }
        if message.isEmpty {
            println("\(f) - \(sline) - \(funcName)")
        }else{
            println("\(f) - \(sline) - \(funcName)\n -> \(message)")
        }
    #endif
}

出力結果
ViewController.swift                          -   65 - onChangeTimeScale
 -> selectedIndex : 0