Typecast UnsafeMutablePointer <void>到UnsafeMutablePointer＆lt; #Struct type＃＆gt; </void>

Question

我在Swift中创建了一个名为RGB的结构，很简单：

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>!。

我希望为此指针malloc一些空间，但malloc返回UnsafeMutablePointer<Void>，我不能像下面那样强制转换它：

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

无论如何要解决这个问题？谢谢你的帮助！

Answer 1

我想你想说的是这样的：

imageData = UnsafeMutablePointer<PixelRGB>.alloc(dataLength)

Answer 2

您是否尝试过以下操作？

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

参考：Using Legacy C APIs with Swift