swift 警告 : 'weak' should not be applied to a property declaration in a protocol

Question

看起来像weak references will be disallowed in protocols .那么如果我想添加一个弱引用，我应该怎么做呢？有更好的主意吗？

protocol PipelineElementDelegate: class {
    func someFunc()
}
protocol PipelineElement {
    weak var delegate: PipelineElementDelegate? { get set}
}

Answer 1

只需从协议(protocol)中删除 weak 关键字，并在符合类型中将属性声明为 weak 即可:

class SomeClass: PipelineElement {
    weak var delegate: PipelineElementDelegate?
}