This was my first reaction as well, but then I realized I hadn't done much currying in Swift and half forgot it was a feature.

Maybe you can bring it back when we get hygienic macros (Swift 4.0? fingers crossed)

The currying was cool. I had to read the pull requests on that one and it seems that it was removed because it complicated language development. I'm hoping they bring it back in a modified more extensible way!