<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">If you look at the <a href="https://github.com/apple/swift/blob/master/stdlib/public/core/Sequence.swift#L325" class="">source for Sequence</a>, you can see that the protocol declares a ton of methods and properties; but in fact, all you need to provide is Element, Iterator and makeIterator. The rest comes for free, but can be specialized.<div class=""><br class=""></div><div class="">Of course, I don't want to work more than I need to. However, I find that I'm having trouble figuring out what I get for free when I implement a protocol. In principle, I like conditional conformances and synthesized implementation of protocol methods, but I find that they both make it harder to figure out what I need to implement, and what are going to be the performance characteristics of methods that I choose to not implement.<br class=""><div class=""><br class=""></div><div class="">I feel like this is perceived to be a problem by a lot of other people. Is there anything that can make it easier to figure out what you get for free?</div></div><div class=""><br class=""></div><div class="">Félix</div></body></html>