UnsafeMutablePointer初始化

Question

1. let context = CGContext(...)
2. context.draw(...)
3. let buffer = UnsafeMutablePointer<UInt32>(context.data) // error here  

使用Swift 3，第3行会产生一个错误：

Cannot invoke initializer for type 'UnsafeMutablePointer<UInt32>' with an argument list of type '(UnsafeMutableRawPointer?)'

有没有办法将UnsafeMutableRawPointer转换为UnsafeMutablePointer在初始化时作为参数接受的任何适当类型？

顺便说一句，UnsafeMutablePointer的类引用可以找到here。

Answer 1

我想这会进行初始化。

    let ptr = context.data
    let data = ptr!.assumingMemoryBound(to: UnsafeMutablePointer<UInt32>.self).pointee
    let pixelBuffer = UnsafeMutablePointer<UInt32>(data)