> On Oct 17, 2017, at 11:20 AM, Kevin Nattinger <sw...@nattinger.net> wrote:
>
> Hmm, I'm not sure that would work with the covariant requirement. The
> associated type one could:
> func firstNames<U: Unordered>(ofPeople people: U<MapResultType: Person>) ->
> U.MapResultType<Element: String> {
> return people.map { $0.firstName }
> }
>
> If the sequence you put in maps to an ordered sequence, you get the ordered
> sequence out.
> That said, I can see how the generics there could get out-of-hand as you add
> more operations… -> U.MapResultType.FilterResultType.MapResultType…<Element:
> String>
Even in the simple case this leaks an implementation detail (that we’re using
map) into the signature.
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