Ben Boeckel

Yeah, CMake has moved a lot since then. It'd take a decent chunk of time to rebase the work at this point.

Well, there are some additional methods that may make sense on `TtlCacheSet` that (might?) not make as much on `TtlCacheMap`: intersection, union, etc.

Well, my need is less now (I actually needed to store a `bool`, not a singleton), but the request could still make sense for someone else.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105397

We also have the line continuation splits after @boris-kolpackov's paper. A few existing examples may now be ill-formed after that as well.

I'll have to respin the Docker image with new versions of things.

Seems the Cirrus CI [can do this](https://cirrus-ci.org/guide/docker-builder/).

Hmm. The docs mention that using an existing image can seed the cache and skip over unnecessary steps. I think if we place the compilers first in the file, then...

`ccache` may also be able to help here. CirrusCI has decent caching support, though we'll need some way to derive a cache key from the `.ccache` directory.

I've pushed a `.cirrus.yml` to the `docker` branch but it seems that it is ignored?