https://github.com/apple/swift/blob/master/stdlib/public/core/OptionSet....

Optional 学习 https://github.com/apple/swift/blob/master/stdlib/public/cor...

下图是在手机设置里点击钉钉APP后的页面： 设置页面

https://www.jianshu.com/p/89ba5fd25762

https://blog.csdn.net/weixin_39339407/article/details/81162726

https://www.jianshu.com/p/f6f2af694869

https://www.jianshu.com/p/92d4715115b8

https://blog.csdn.net/yimiyuangguang/article/details/83096003

https://www.jianshu.com/p/40cc2a120551