前に読んだのは↓っぽい。

Chris Lattner Jun 13 Moderate -1. Never is special because it has no instances - it is uninhabited by design. This means that it can conform to all protocols. I'd rather see a global solution rather than cherry picking these two specific protocols.

Joe_Groff Jun 13 If we're cherry-picking protocols to conform Never to, Error seems like another good one to whitelist, since it's useful to use Never to close off the error path in Result<T, Never>-like abstractions.

https://forums.swift.org/t/se-0215-conform-never-to-equatable-and-hashable/13586 (edited)

SE-0215 - Conform Never to Equatable and Hashable

The review of SE-0215 — Conform Never to Equatable and Hashable begins now and runs through June 19, 2018. The proposal is authored by @mdiep. Reviews are an important part of the Swift evolution process. All review feedback should be either on this forum thread or, if yo...