类型'MyWeights'不符合协议'NSCopying'

Question

我正在使用Metal Performance Shader来设置神经网络，并在编写权重初始化类时遇到问题：类型'MyWeights'不符合协议'NSCopying'。是什么导致了错误，以及如何解决这个问题？

PS。我尝试通过添加copy（）函数来修复它，但是我不知道要返回什么或它意味着什么。

import Foundation
import MetalPerformanceShaders

class MyWeights: NSObject, MPSCNNConvolutionDataSource {
//Error: Type 'MyWeights' does not conform to protocol 'NSCopying'

/*
func copy(with zone: NSZone? = nil) -> Any {
    return self
}
*/

let name: String
let kernelWidth: Int
let kernelHeight: Int
let inputFeatureChannels: Int
let outputFeatureChannels: Int

var data: Data?

init(name: String, kernelWidth: Int, kernelHeight: Int,
     inputFeatureChannels: Int, outputFeatureChannels: Int,
     useLeaky: Bool = true) {
    self.name = name
    self.kernelWidth = kernelWidth
    self.kernelHeight = kernelHeight
    self.inputFeatureChannels = inputFeatureChannels
    self.outputFeatureChannels = outputFeatureChannels
}

func dataType() -> MPSDataType {
    return .float32
}

func descriptor() -> MPSCNNConvolutionDescriptor {
    let desc = MPSCNNConvolutionDescriptor(kernelWidth: kernelWidth,
                                           kernelHeight: kernelHeight,
                                           inputFeatureChannels: inputFeatureChannels,
                                           outputFeatureChannels: outputFeatureChannels)
    return desc
}

func weights() -> UnsafeMutableRawPointer {
    return UnsafeMutableRawPointer(mutating: (data! as NSData).bytes)
}

func biasTerms() -> UnsafeMutablePointer<Float>? {
    return nil
}

func load() -> Bool {
    if let url = Bundle.main.url(forResource: name, withExtension: "dat") {
        do {
            data = try Data(contentsOf: url)
            return true
        } catch {
            print("Error: could not load \(url): \(error)")
        }
    }
    return false
}

func purge() {
    data = nil
}

func label() -> String? {
    return name
}

}

Answer 1

它告诉你到底要做什么。

你需要声明你的类符合NSCopying协议，然后你需要实现该协议中唯一的函数，copy(with:)

class MyWeights: NSObject, MPSCNNConvolutionDataSource, NSCopying {

    func copy(with zone: NSZone? = nil) -> Any {
        return MyWeights(
          name: self.name,
          kernelWidth: self.kernelWidth,
          kernelHeight: self.kernelHeight,
          inputFeatureChannels: self.inputFeatureChannels,
          outputFeatureChannels: self.outputFeatureChannels,
          useLeaky: self.useLeaky)
    }
    //The rest of your class
}

Answer 2

您必须实现整个NSCopying协议

class MyWeights: NSObject, MPSCNNConvolutionDataSource, NSCopying {

    init(/* ... */) {
    // your init...

        super.init() // NSObject init
    }

    // add this method
    func copy(with zone: NSZone? = nil) -> Any {
        return super.copy() // NSObject copy
    }
    //The rest of your class
}