Swift feels very immature in many areas. For example, Swift fails with generics out of most ordinary cases. Today, you still can't restrict protocol conformance (inheritance clause) to a type-constrained extension. That's a big issue with arrays. A struct wrapper is the go-to solution for many things where Swift generics break down and it's not the best or more elegant way to resolve its limitations. Many hopes for Swift 3.0 but I doubt they'll fix those.