指针 – 在swift中将CFContextRef转换为可变的void指针？

我正在尝试将此objc代码转换为 swift：

CGContextRef contextRef = CGBitmapContextCreate(NULL,proposedRect.size.width,proposedRect.size.height,CGImageGetBitsPerComponent(imageRef),colorSpaceRef,(CGBitmapInfo)kCGImageAlphaPremultipliedFirst);
NSGraphicsContext *context = [NSGraphicsContext graphicsContextWithGraphicsPort:contextRef flipped:NO];

到目前为止,我最终得到了这个：

var bitmapContext: CGContext = CGBitmapContextCreate(data,UInt(proposedRect.width),UInt(proposedRect.height),CGImageGetBitsPerComponent(image),colorSpace,CGBitmapInfo(CGImageAlphaInfo.PremultipliedFirst.toRaw()))
let context = NSGraphicsContext(graphicsPort: bitmapContext,flipped: false)

问题是CGBitmapContextCreate返回CGContext类型,NSGraphicsContext初始化程序接受graphicsPort作为CMutableVoidPointer类型.那么如何将CGContext转换为CMutableVoidPointer呢？

相关的反向型铸造在这里找到,但它没有给我提供太多帮助
How to convert COpaquePointer in swift to some type (CGContext? in particular)

解决方法

我最终使用reinterpretCast函数返回bitmapContext地址的中间Int变量.

var bitmapContext: CGContext = CGBitmapContextCreate(...)

let bitmapContextAddress: Int = reinterpretCast(bitmapContext)
let bitmapContextPointer: CMutableVoidPointer = copaquePointer(UnsafePointer<CGContext>(bitmapContextAddress))
let context = NSGraphicsContext(graphicsPort: bitmapContextPointer,flipped: false)