类型广播UnsafeMutablePointer<Void>到UnsafeMutablePointer<#Struct type#>

Question

我在Swift中创建了一个名为RGB的结构，非常简单：

struct PixelRGB {
    var r: CUnsignedChar = 0
    var g: CUnsignedChar = 0
    var b: CUnsignedChar = 0

    init(red: CUnsignedChar, green: CUnsignedChar, blue: CUnsignedChar) {
        r = red
        g = green
        b = blue
    }
}

我有一个指针var imageData: UnsafeMutablePointer<PixelRGB>!。

我希望为这个指针设置一些空格，但是malloc返回UnsafeMutablePointer<Void>，我不能像下面这样转换它：

imageData = malloc(UInt(dataLength)) as UnsafeMutablePointer<PixelRGB> // 'Void' is not identical to `PixelRGB`

要解决这个问题吗？谢谢你的帮助!

Answer 1

你试过以下几种方法吗？

imageData = unsafeBitCast(malloc(UInt(dataLength)), UnsafeMutablePointer<PixelRGB>.self)

参考文献：在Swift中使用遗留C API