UnsafePointer<UInt8> initializer in Swift 3

Question

I have a receipt validation class that is deprecated since Swift 3 has released. I fixed some issues, but I still have many ...

Here is the GitHub source code I used : https://gist.github.com/baileysh9/4386ea92b047d97c7285#file-parsing_productids-swift and https://gist.github.com/baileysh9/eddcba49d544635b3cf5

1. First Error :

       var p = UnsafePointer<UInt8>(data.bytes)
   

Compiler throws : Cannot invoke initializer for type UnsafePointer(UInt8) with an argument list of type UnsafeRawPointer

2. Second error

   while (ptr < end)
   

Binary operators < cannot be applied to two UnsafePointer(UInt8) operands

Thank you very much in advance :)

EDIT

Thanks to LinShiwei answer I found a solution to UnsafePointer declaration. It compiles but not tested yet (because other errors avoid me to test) :

 func getProductIdFromReceipt(_ data:Data) -> String?
{
  let tempData: NSMutableData = NSMutableData(length: 26)!
  data.withUnsafeBytes {
        tempData.replaceBytes(in: NSMakeRange(0, data.count), withBytes: $0)
    }

    var p: UnsafePointer? = tempData.bytes.assumingMemoryBound(to: UInt8.self)

Answer 1

1. In Swift 3, you cannot init an UnsafePointer using an UnsafeRawPointer.

   You can use assumingMemoryBound(to:) to convert an UnsafeRawPointer into an UnsafePointer<T>. Like this:

   var ptr = data.bytes.assumingMemoryBound(to: UInt8.self)
   

2. Use debugDescription or distance(to:) to compare two pointer.

   while(ptr.debugDescription < endPtr.debugDescription)
   

   or

   while(ptr.distance(to:endPtr) > 0)
   

Answer 2

May have recently changed to just this, without the ".bytes." part:

var p: UnsafePointer = data.assumingMemoryBound(to: UInt8.self)

from the original:

var p = UnsafePointer<UInt8>(data.bytes)