如何将数组 `UnsafePointer<DSPComplex>` 转换为浮点数数组？

Question

如何将数组 UnsafePointer<DSPComplex> 转换为 Swift 中的浮点数数组？

我看过，但是因为我是 swift 的新手，所以我不知道如何为浮点数数组做这件事。

Answer 1

DSPComplex 是一个包含虚数和实数 Float 值的结构。那是两个花车。它不能转换为浮点数数组。但是，您必须先将其转换为 UnsafeBufferPointer，然后才能将其传递给数组。然后你有一个 Swift 个 DSPComplex 结构数组。

func arrayForDSPComplex(pointer: UnsafePointer<DSPComplex>, count: Int) -> [DSPComplex] {
   let buffer = UnsafeBufferPointer<DSPComplex>(start: pointer, count: count)
   return Array(buffer)
}

如果需要，您甚至可以使用泛型对其进行泛化。

func arrayForPointer<T>(_ pointer: UnsafePointer<T>, count: Int) -> [T] {
    let buffer = UnsafeBufferPointer(start: pointer, count: count)
    return Array(buffer)
}

对于可变指针，您需要另一个函数。

func mutableArrayForPointer<T>(_ pointer: UnsafeMutablePointer<T>, count: Int) -> [T] {
    let buffer = UnsafeMutableBufferPointer(start: pointer, count: count)
    return Array(buffer)
}

您可以稍微改进一下，将函数作为指针类型的扩展。

extension UnsafePointer {
    func arrayCopying(elementCount: Int) -> [Pointee] {
        let buffer = UnsafeBufferPointer(start: self, count: elementCount)
        return Array(buffer)
    }
}

extension UnsafeMutablePointer {
    func arrayCopying(elementCount: Int) -> [Pointee] {
        let buffer = UnsafeMutableBufferPointer(start: self, count: elementCount)
        return Array(buffer)
    }
}
``

如何将数组 `UnsafePointer<DSPComplex>` 转换为浮点数数组？

How do I convert an array `UnsafePointer<DSPComplex>` to an array of Floats?

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