类型“布尔"不符合协议“布尔类型" [英] Type 'Boolean' does not conform to protocol 'BooleanType'

问题描述

根据Apple文档(和

In attempting to create a Launch Helper as per the Apple docs (and tutorial-ized), I seem to be hitting a hiccup caused by porting the Objective-C code into Swift... who's compiler couldn't be any more redundant in this case.

import ServiceManagement

let launchDaemon: CFStringRef = "com.example.ApplicationLauncher"

if SMLoginItemSetEnabled(launchDaemon, true) // Error appears here
{
    // ...
}

错误似乎始终是:

Type 'Boolean' does not conform to protocol 'BooleanType'

我尝试过在多个位置强制转换为Bool，以防万一我只是处理> (由Obj-C或Core Foundation带来)，无济于事.

I have tried casting to Bool in a number of locations, in case I'm simply dealing with a redundant, archaic primitive (either brought in by Obj-C or Core Foundation), to no avail.

以防万一，我尝试投射响应:

Just in case, I have tried casting the response:

SMLoginItemSetEnabled(launchDaemon, true) as Bool

会产生错误:

'Boolean' is not convertible to 'Bool'

...认真吗?

推荐答案

Boolean是历史Mac类型"，并声明为

Boolean is a "historic Mac type" and declared as

typealias Boolean = UInt8

因此它会编译:

if SMLoginItemSetEnabled(launchDaemon, Boolean(1)) != 0 { ... }

---

对于Boolean类型具有以下扩展方法 (而且我不确定此信息是否已发布过，现在无法找到):

---

With the following extension methods for the Boolean type (and I am not sure if this has been posted before, I cannot find it right now):

extension Boolean : BooleanLiteralConvertible {
    public init(booleanLiteral value: Bool) {
        self = value ? 1 : 0
    }
}
extension Boolean : BooleanType {
    public var boolValue : Bool {
        return self != 0
    }
}

您可以只写

if SMLoginItemSetEnabled(launchDaemon, true) { ... }

• BooleanLiteralConvertible扩展名允许自动转换 第二个参数true到Boolean.
• BooleanType扩展名允许Boolean的自动转换 if语句将函数的值返回到Bool.
• The BooleanLiteralConvertible extension allows the automatic conversion of the second argument true to Boolean.
• The BooleanType extension allows the automatic conversion of the Boolean return value of the function to Bool for the if-statement.

更新:从 Swift 2/Xcode 7 beta 5开始，历史Mac类型" Boolean 映射为Bool到Swift，这使得上述扩展方法 已过时.

Update: As of Swift 2 / Xcode 7 beta 5, the "historic Mac type" Boolean is mapped to Swift as Bool, which makes the above extension methods obsolete.

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