try! Swift Tokyo Conference 2018 - try! Swift is an immersive community gathering about Apple Technologies, Swift Language Best Practices, Application Development in Swift, Server-Side Swift, Open Source Swift, and the Swift Community in Tokyo! Topic - The diamond of variance Speaker - Vu Nhat Minh Twitter - https://twitter.com/orakaro Bio - Orakaro is an iOS Engineer at Mercari currently working on Atte, the Japanese community classifieds app. Though he had years of backend web programming experiences using languages such as Python or Scala, he decided to move on as a native mobile engineer after figuring out that smartphone apps were doing a better job of impacting the world each and every day. He also enjoys digging around concepts and theories in functional programming, learning abstract algebra and excited to help bring those academy concepts closer to industry products. In spare time Orakaro enjoys playing the ancient game of Go. He is a 2 dan amateur go player. Abstract - Generics is always a confusing yet interesting topic in Swift language. Generics Manifesto did a great explanation on how Swift's type system is built for practicality more than principle. But if we look at the theory of 'diamond of variance', we can have another point of view about the completeness of a type system and how Swift generics fit in with the theory. This talk will explain what really is Variance, Covariance, Contravariance in Swift as well as the last amazing piece of above diamond: The Phantom Type. try! Swift Tokyo Twitter - https://twitter.com/tryswiftconf try! Swift Tokyo Twitter Hashtag - https://twitter.com/hashtag/tryswiftconf try! Swift Website - https://www.tryswift.co/ try! Swift Conference Photos - https://www.flickr.com/photos/tryswift/albums try! Swift Conference Contact - info@tryswift.co try! Swift Conference © 2018 - Powered by NatashaTheRobot