////
protocol ExampleProtocol{
var simpleDescription :String{get}
mutating func adjust()
}
class SimpleClass:ExampleProtocol{
var simpleDescription:String = "A very simple class."
var anotherProperty:Int = 70106
func adjust() {
simpleDescription += "Now 100% adjusted"
}
}
原文：http://www.cnblogs.com/yshgxm/p/5243886.html