FreeBSD10 gets a nice new tree data structure called "PC Trie" (path-compressed trie). This data structure is broadly useful and something worth carrying in libbsd.
The difference when compared with other data structure headers is that this one requires implementation coming from .c files, and the interface is internal to the kernel. And while porting it to userland might not be difficult, it means not even on FreeBSD userland code will be using pctries. So I'd rather not add it to libbsd as long as this is not userland usable. Or that's what it looks like from my local FreeBSD tree.
Thanks for the suggestion though.
Okay, that sounds fine to me. I would expect to see *BSD userspace users eventually, but it's still pretty new. Let's punt for now.