迅速和布尔 [英] Swift and Boolean

问题描述

函数AUGraphIsInitialized的定义如下：

The function AUGraphIsInitialized is defined like this:

func AUGraphIsInitialized(inGraph: AUGraph, outIsInitialized: CMutablePointer<Boolean>) -> OSStatus

所以，您这样称呼它：

var status : OSStatus = OSStatus(noErr)
var outIsInitialized:Boolean = 0
status = AUGraphIsInitialized(self.processingGraph, &outIsInitialized)

可以。但是如何检查呢？

That works. But how do you check it?

布尔值定义为CUnsignedChar（在MacTypes.h中）

Boolean is defined as an CUnsignedChar (in MacTypes.h)

因此，则无法执行以下操作：

So, you cannot do this:

if outIsInitialized {
    // whatever
}

并且您无法投射它（找不到重载...）

And you cannot cast it (could not find an overload...)

var b:Bool = Bool(outIsInitialized)

或使用Swift的 as

or with Swift's "as"

var b:Bool = outIsInitialized as Bool

所以，我的问题是：如何在Swift中使用布尔值？

So, my question is: how do you use Boolean in Swift?

推荐答案

C表示布尔值true（具有非零值）和false（具有零值），因此您可以针对测试 outIsInitialized 0 ：

C represents the Boolean value true with a nonzero value and false with a zero value, so you can just test outIsInitialized against 0:

if outIsInitialized != 0 {
    // outIsInitialized is true
}

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