alt Hacker News> If you really want an arena like behavior you could allocate a byte slice and use unsafe to cast it to literally any type.
A word of caution. If you do this and then you store pointers into that slice, the GC will likely not see them (as if you were just storing them as `uintptr`s)
You need to ensure that everything you put in the arena only references stuff in the same arena.
No out pointers. If you can do that, you're fine.