> I guess I can't find them because they are unstable, right? They're in the [language manual](https://nim-lang.org/docs/manual.html#generics-type-classes), right after `type classes`, as they used to be known as "user defined type classes". Beware that some [parts](https://nim-lang.org/docs/manual.html#generics-vtable-types) that have been in the documentation for months now are not even in the compiler. While I'd love to have that feature available, I believe it's false advertising to present it in the manual as though it were.
Unless you feel like being a trail blazer, I'd avoid certain exciting features of Nim that are not really polished yet, like concepts, and be careful of others (eg method combined with generics).
