Matt talks on NSHipster about default protocol implementations. I already said that it's a feature that I miss in Siwft (and in Objective-C). I'd never saw any big talk about this in our community so now that Matt has written about it I hope that this thinking spreads ;)

The one major shortcoming of protocols, both in Swift and Objective-C, is the lack of a built-in way to provide default implementations for methods, as one might accomplish in other languages with mixins or traits.