如何更新Swift 3 UnsafePointer的数据语句？

Question

I'm getting the error below for this statement:

 let data = Data(bytes: UnsafePointer<UInt8>(cubeData), count: cubeData.count * MemoryLayout<Float>.size)

cubeData is defined as: var cubeData = [Float](repeating: 0, count: size * size * size * 4)

Error:

 'init' is unavailable: use 'withMemoryRebound(to:capacity:_)' to temporarily view memory as another layout-compatible type.

How can I fix this?

Thanks!

Answer 1

You could use Array.withUnsafeBufferPointer to obtain a buffer pointer (ie a pointer to an array with its length). Then use Data.init(buffer:) to initiate the data from a buffer pointer.

let cubeData: [Float] = [1.1, 2.2, 3.3, 4.4]

let b = cubeData.withUnsafeBufferPointer { Data(buffer: $0) }

print(b as NSData)
// <cdcc8c3f cdcc0c40 33335340 cdcc8c40>