抛出Swift2闭包

Question

我试图创建一个可以抛出的闭包，并将其作为参数传递给另一个函数。例如：

extension NSManagedObjectContext {

  /// The same as performBlockAndWait, except it can handle closures that throw.
  func performBlockAndWaitOrThrow(block: (() -> throws Void)) throws {
    // ...
    try block()
  }
}

注意，希望块的参数是一个可以抛出的闭包。

然而，这并不能编译。有办法这样做吗？

Answer 1

throws关键字应该在箭头之前出现。该文件汇编如下：

extension NSManagedObjectContext {

    /// The same as performBlockAndWait, except it can handle closures that throw.
    func performBlockAndWaitOrThrow(block: (() throws -> Void)) throws {
        // ...
        try block()
    }
}