TLDR; It is like compiler substitution :) HTTR; To understand associatedtypes: https://02infinity.medium.com/understanding-swift-protocol-associated-types-ca717d091b56 I’ve had a hard time wrapping my head around ‘some’ keyword (introduced in swift 5.1). Now that I have that “Ah-ha!” moment, I thought I may be able to help others understand, with this article. I’ll start with…