swift - 在 Swift 3 中使用泛型参数调用闭包时发生奇怪的崩溃

Question

这里我有一个协议(protocol):

protocol CrashProtocol {
    associatedtype T

    static func tryCrash(_ dummyInt: Int,
                         with closure: ((T) -> Void))
}

实现它的基类:

class Crash<M>: CrashProtocol {
    typealias T = M

    class func tryCrash(_ dummyInt: Int,
                        with closure: ((M) -> Void)) {
        print("Crash tryCrash")
    }
}

派生类继承基类:

class DerivedCrash: Crash<DummyObject> {

    override class func tryCrash(_ dummyInt: Int, with closure: ((DummyObject) -> Void)) {
        super.tryCrash(dummyInt, with: closure)

        print("Derived tryCrash")
        let obj = DummyObject.init()
        closure(obj)
    }
}

现在每当我尝试

DerivedCrash.tryCrash(1) { _ in
            print("Never reach here")
}

我遇到“EXC_BAD_ACCESS”崩溃。你可以找到我的测试代码 here . 我已经完成了我的调试工作，但只发现导致崩溃的内存地址指向一个 Swift.Int 实例，我不使用它。 如果我稍微更改调用代码，代码将在执行闭包后崩溃。

DerivedCrash.tryCrash(1) { (obj: DummyObject) in
    //print("Never reach here")
    print("print as expected and then crash")
}

如果有人能切碎一些光线，我将不胜感激..

Answer 1

我已将 NSObject 添加到 associatedtype 中，现在它不会崩溃。 它没有回答您的问题，但也许这个临时解决方案会对您有所帮助

protocol CrashProtocol {
    associatedtype T: NSObject

    static func tryCrash(_ dummyInt: Int,
                         with closure: ((T) -> Void))
}

class Crash<M:NSObject>: CrashProtocol {
    typealias T = M

    class func tryCrash(_ dummyInt: Int,
                        with closure: ((M) -> Void)) {
        print("Crash tryCrash")
    }
}