Why are swift_projectBox and swift_release commented out?

[stephencelis]

Following discussion here #40 (reply in thread), and the linked reimplementation of Mirror, I found that it relied on swift_projectBox and swift_release, which are both currently commented out on the main branch. Is there a reason these functions have been commented out? Is there a way to reimplement Mirror without them using other tools?

[NSExceptional]

I suspect there are other ways to allow the compiler to trigger a release for you, but there's definitely a way to pull things out of an AnyExistentialContainer without swift_projectBox (assuming that's what it's for?)

Looks like Azoy has been pretty busy since joining Apple. I can try to help if there's something you're trying to do in particular?

[stephencelis]

@NSExceptional My questions came about when I was looking to add runtime enum extraction functionality to swift-case-paths. We were previously traversing a mirror, which was reliable but about 1,000x slower than a manual if case let. A couple of us were able to work out most of the runtime details (seen in this file), and now the implementation is only about 2-5x slower than manual if case let.

I keep dreaming for enum key paths to make it into the language though 😅