https://forums.swift.org/t/opaque-result-types/15645 Generalized Existential っぽいけどちょっと違う func returnStringCollection() -> opaque Collection where _.Element == String みたいなのを出来るようにする提案 (edited)

Hello all, Here's a proposal I've been thinking about for a while (I blame Rust), but which came up again due to the review of SE-0222. Now seems like a fine time to pitch it. The complete proposal follows, or you can go look at the rendered version. Introduction This propo...