与Objective C的Swift 2.0互操作不能按预期工作？(Swift 2.0 interop with Objective C not working as expected?)

与Objective C的Swift 2.0互操作不能按预期工作？(Swift 2.0 interop with Objective C not working as expected?)

我正在将Swift 1.2框架移植到2.0。 在修复了新的Swift 2.0错误处理方案的300万编译器错误之后，我终于能够链接我的测试应用程序（用Objective C编写）来使用更新的框架。

Xcode版本7.0 beta 3（7A121l）

但是，我遇到了一个问题。 一些Swift函数不再生成到Objective C测试应用程序使用的自动生成的Objective C头文件（MyFramework-Swift.h）中。

下面是一个未公开的函数示例:(我的实际框架函数返回了枚举，但我试图简化以更清楚地说明问题）。

public func calculateImportantValueDangerously() throws -> Int { return 42 }

请注意，像下面这样的其他函数实际上会按预期公开（并且可以调用）：

public func doSomething() { } public func doSomethingDangerous() throws { } public func calculateMeaninglessValue() -> Int { return -1 }

这是Objective C方面：

MyClass *newInstance = [[MyClass alloc] init]; [newInstance doSomething]; NSError *error = nil; [newInstance doSomethingDangerousAndReturnError:&error]; long meaninglessValue = [newInstance calculateMeaninglessValue]; NSLog(@"%ld", meaninglessValue); long importantValue = [newInstance calculateImportantValueDangerouslyAndReturnError:&error]; <-COMPILE ERROR NSLog(@"%ld", importantValue);

从观看此视频开始，我原本预计它应该“正常工作”：

https://developer.apple.com/videos/wwdc/2015/?id=401

...但似乎我们目前无法使用抛出和返回值的函数。

这是一个错误，还是没有实现的功能？ 如果我在某处发布说明中遗漏了某些内容，我表示歉意。

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I'm porting a Swift 1.2 framework to 2.0. After fixing the 3 million compiler errors courtesy of the new Swift 2.0 error handling scheme, I was finally able to link my test app (written in Objective C) to use the updated framework.

Xcode version 7.0 beta 3 (7A121l)

However, I ran into a problem. Some Swift functions are no longer generated into the automatically generated Objective C header (MyFramework-Swift.h) used by the Objective C test app.

Here is an example of a function that is not exposed: (My actual framework function returned an enum, but I tried to simplify to illustrate the problem more clearly).

public func calculateImportantValueDangerously() throws -> Int { return 42 }

Note that other functions like the following actually do get exposed as expected (and can be called):

public func doSomething() { } public func doSomethingDangerous() throws { } public func calculateMeaninglessValue() -> Int { return -1 }

Here's the Objective C side:

MyClass *newInstance = [[MyClass alloc] init]; [newInstance doSomething]; NSError *error = nil; [newInstance doSomethingDangerousAndReturnError:&error]; long meaninglessValue = [newInstance calculateMeaninglessValue]; NSLog(@"%ld", meaninglessValue); long importantValue = [newInstance calculateImportantValueDangerouslyAndReturnError:&error]; <-COMPILE ERROR NSLog(@"%ld", importantValue);

From watching this video, I had expected that it should "just work":

https://developer.apple.com/videos/wwdc/2015/?id=401

...but it seems like we can't currently use functions that both throw and return a value.

Is this a bug, or not implemented feature? My apologies if I missed something in the release notes somewhere.

Any advice appreciated.

最满意答案

这不可能。

如果您使用@objc注释您的方法，您将看到问题。

抛出方法不能标记为@objc，因为它返回一个'Int'类型的值; 返回'Void'或桥接到Objective-C类的类型

您只能返回对象，不支持基元。

It is not possible.

If you annotate your method with @objc you will see the problem.

Throwing method cannot be marked @objc because it returns a value of type 'Int'; return 'Void' or a type that bridges to an Objective-C class

You can return only objects, primitives are not supported.