Where do you miss user-definable attributes from? I'm not aware of any analogous ObjC feature. The `where` keyword is also used when defining generic functions

Where do you miss user-definable attributes from? I'm not aware of any analogous ObjC feature. The `where` keyword is also used when defining generic functions/types. As the expression level, it used to be used in `if` too, but that syntax was changed such that it no longer uses `where` (but still retains the same power). Where else were you expecting it to be used? You can do a non-allocating `count(where:)` today with `lazy.filter(where: …).count`.