将重新抛出功能保存为非投掷闭包

时间:2017-04-09 07:31:21

标签: swift closures throw rethrow

据我了解,rethrows基本上从单个声明/定义创建了两个函数,如下所示:

func f(_ c: () throws -> Void) rethrows { try c()}

// has the same effect as declaring two seperate functions, with the same name:

func g(_ c: () throws -> Void) throws { try c() }
func g(_ c: () -> Void) { c() }

如果我有一个重新抛出函数,比如f,有没有办法将它保存为“非投掷”形式的闭包?假设,就像这样:

let x: (() -> Void) -> Void = f
// invalid conversion from throwing function of type '(() throws -> Void) throws -> ()' to non-throwing function type '(() -> Void) -> Void'

x{ print("test") } // "try" not necessary, because x can't throw

1 个答案:

答案 0 :(得分:3)

在有人提出更好的解决方案之前:使用包装器

func f(_ c: () throws -> Void) rethrows { try c()}

let x: (() -> Void) -> Void = { f($0) }