Beware: As of a few months ago, when I tried to use the lifetime features shown off in this post, I ran into constant compiler crashes with very simple programs, until I gave up and wrote off the features as unusable. This happened on both stable and nightly compilers. I guess they work well enough for this TrueType interpreter, but I suspect they’re using a narrow subset of what the features are supposed to support. Or maybe things have been fixed very recently.
That said, I’m looking forward to using Swift lifetimes once they actually work!
The work discussed in this post shipped in the OS last year (fall 2025), so nothing here is dependent on very recent changes.
Average swift experience