如何更新Swift 3的UnsafePointer數據聲明？

Question

我收到以下錯誤這樣的說法：

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

cubeData被定義爲：var cubeData = [Float](repeating: 0, count: size * size * size * 4)

錯誤：

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

我該如何解決這個問題？

謝謝！

Answer 1

您可以使用Array.withUnsafeBufferPointer來獲取緩衝區指針（即指向具有其長度的數組的指針）。然後使用Data.init(buffer:)從緩衝區指針啓動數據。

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>