arrays - 通用项目的数组扩展 - 协议不可转换为父协议

Question

编码：

protocol AProtocol {}

protocol ABProtocol: AProtocol {}

struct ABStruct: ABProtocol {}

struct Wrapper<T> {
    let object: T
}

extension Array where Element == Wrapper<AProtocol> {
    func merge(with otherArray: [Element]) {}
}

let wrapper1: Wrapper<ABProtocol> = Wrapper(object: ABStruct())
let wrapper2: Wrapper<ABProtocol> = Wrapper(object: ABStruct())
let wrappers1 = [wrapper1, wrapper2]
let wrappers2 = [wrapper2, wrapper1]
// Following produces compilation error:
// '[Wrapper<ABProtocol>]' is not convertible to 'Array<Wrapper<AProtocol>>'
let result = wrappers1.merge(to: wrappers2)

这会产生编译错误：

'[Wrapper<ABProtocol>]' is not convertible to 'Array<Wrapper<AProtocol>>'

即使ABProtocol继承（扩展）AProtocol。

是否可以为受限于协议的通用元素声明Array（或Collection）扩展以及从它继承的任何子协议？

要点： https ://gist.github.com/lukaszmargielewski/48fe181264bbc468e1c3b80aec0a6516