withExtendedLifetime

withExtendedLifetime.swift

/**


/// f가 리턴하기 전에 `x`가 사라지지 않았을 때만 `f(x)`를 평가하고 결과를 반환한다.
func withExtendedLifetime<T, Result>(x: T, f: (T) -> Result) -> Result
func withExtendedLifetime<T, Result>(x: T, f: () -> Result) -> Result

**/
func getClosure() -> ()->() {
    
    var p = "yes"
    
    func expired() {
        println("is it alive?")
        withExtendedLifetime(p) {
            (s:String) in println(s)
        }
    }
    return expired
}


var closure = getClosure()
closure()

wtf