Marcin Moskala is an experienced developer and Kotlin trainer. He is the founder of the Kt. Academy, an official JetBrains partner for Kotlin training, author of the books Effective Kotlin, Kotlin Coroutines, and Android Development with Kotlin. He is also the main author of influential articles about Kotlin and a speaker invited to many programming conferences.
Marcin Moskała
Developer during the day, author at night, trainer at Kt. Academy
Office Hours: All Things Kotlin Language
Have a chat with Developer Advocates from JetBrains and industry experts about anything Kotlin related on your mind. Talk about language evolution, tooling, development practices, and more!
Talk Title
Kotlin variance modifiers and Covariant Object Nothing pattern
Variance modifiers are one of those parts of Kotlin that all use (often unconsciously), but only a small portion of developers understand it well. It gives us the convenience of using collection or functional types and lets us implement popular patterns, like Covariant Nothing Object (used by emptyList or many data structures) or Covariant Nothing Class (used by Either and on many implementations of Result). I will deeply explore those concepts and patterns in this presentation, concentrating on practical use cases.