符合关联类型的协议

Question

我坚持斯威夫特语法。这个代码示例不会编译，我也找不到原因。上面写着

类型'TextMessageViewModelDefaultBuilder‘不符合协议'ViewModelBuilderProtocol’

import Foundation

protocol MessageModelProtocol { }
protocol MessageViewModelProtocol { }

protocol TextMessageViewModelProtocol:MessageViewModelProtocol {}
protocol TextMessageModelProtocol:MessageModelProtocol {}

protocol ViewModelBuilderProtocol {
    associatedtype ModelT: MessageModelProtocol
    associatedtype ViewModelT: MessageViewModelProtocol
    func canCreateViewModel(fromModel model: Any) -> Bool
    func createViewModel(_ model: ModelT) -> ViewModelT
}

class TextMessageViewModelDefaultBuilder: ViewModelBuilderProtocol {
    typealias ModelT = TextMessageModelProtocol
    typealias ViewModelT = TextMessageViewModelProtocol

    init() {}

    func createViewModel(_ textMessage: ModelT) -> ViewModelT {
        return ViewModelT()
    }

    func canCreateViewModel(fromModel model: Any) -> Bool {
        return model is ModelT
    }
}

Answer 1

Hamish在评论中指出，在Swift协议中，协议不符合自己的要求。因此，我不能使用协议类型来实现关联类型的需求。