Swift，多行@autoclosure

@autoclosure是否只允许单行代码？示例2和3编译时出错

   class Test {
        typealias TestConstructor = () -> AnyObject
        let constructor: () -> TestConstructor
        init(_ constructor: @escaping () -> TestConstructor) {
            self.constructor = constructor
        }
        init(_ constructor: @autoclosure @escaping () -> TestConstructor) {
            self.constructor = constructor
        }
    
        func executeTest() { }
    }
    
    class CustomObject {
        var title: String
        var message: String
        init(title: String) {
           self.title = title
        }
    }

//示例1：不带@autoclosure的init

Test({
let object = CustomObject(title: "")
object.message = ""
}.executeTest())

Test(
let object = CustomObject(title: "")
object.message = "").executeTest()

//示例2:init和@autoclosure

Test({
let object = CustomObject(title: "")
object.message = ""
}.executeTest())

Test(
let object = CustomObject(title: "")
object.message = "").executeTest()

//示例3:init带有@autoclosure和行分隔符

Test(let object = CustomObject(title: ""); object.message = "").executeTest()

---

它允许

单个表达式

，而不是

单行

。一个表达式可以是多行的，一行可以包含多个表达式。