try! defer! #swift2 #CodePiece #swift #swiftlang

CodePiece.swift

func unreachableDefer() {
    print(#function + " start")
    
    if true { return }
    
    // It will not execute because unreachable
    defer { print("defer-1") }
    print(#function + " end")
}

unreachableDefer()
/*
unreachableDefer() start
*/

func deferTwice() {
    print(#function + " start")
    var i = 0
    
    // Defer does not capture variable when this line reached
    // The value of runtime will be used
    defer { print("defer-1  i=\(i)")  } 
    defer { print("defer-2  i=\(i)")  }
    i = 1
    print(#function + " end")
}

deferTwice()
/*
deferTwice() start
deferTwice() end
defer-2  i=1
defer-1  i=1
*/

func deferIf() {
    print(#function + " start")
    do {
        print("do block start")
        if true {
            // It will execute immediately if 'if-block' ended
            defer { print("defer-if") } 
        } else {
            defer { print("defer-else)") } 
        }
        print("do block end")
    }
    print(#function + " end")    
}

deferIf()
/*
deferIf() start
do block start
defer-if
do block end
deferIf() end
*/


func deferInForloop() {
    print(#function + " start")
    
    for i in 1...5 {
        defer { print("defer-\(i)") } 
    }
    print(#function + " end")
}
deferInForloop()
/*
deferInForloop() start
defer-1
defer-2
defer-3
defer-4
defer-5
deferInForloop() end
*/