C++ On Sea follow-up

Hey Jon, thanks for your talk at C++ On Sea this year. It was very engaging and a great introduction to allocator-aware development. My name is Kal, we had a nice chat after the talk and you directed me here for any questions I may have in the future!

I've been [reading up](https://quuxplusone.github.io/blog/2023/06/02/not-so-quick-pmr/) and thinking about allocators the past week. I am still pretty much a layman when it comes to it, but I'm interested to learn more. My background is in graphics, and memory allocation on the GPU can be a bit more involved than just "give me some space", so I am very curious to see how `std::pmr` changes that paradigm on the CPU as well.

I was wondering if you have any recommendations for purpose-built open source projects that use `std::pmr` in an interesting way? I'd really like to see a real-life example to get a better understanding of when/how polymorphic allocators can be better than the default one, but also how a stateful allocator implementation looks like. I do have some naive ideas, but I am sure there is some really interesting stuff out there!