[loeg]

They seem to enumerate a possible set of valid structures which can hold arbitrary values. I guess it's just so different from C enums I'm having trouble understanding why the name was repurposed. It's probably less different from C++/C#/Java enums (I know at least one/some of those languages have more complicated enums than C).

Sure, tagged union implies a particular implementation that may not always be required, but it's conceptually easy to understand and doesn't have the historical baggage. (Maybe a better description would be strongly typed union? I want to make clear I'm unfamiliar with Rust and just guessing based on the syntax presented.) I think the biggest problem with "tagged union" (or the even longer "strongly typed union") is that it just isn't a good keyword name — it's two (or three) words and fairly long. No one wants to type out 'tagged_union' and from that sense, 'enum' is better. I don't have a better suggestion for you, and IIRC Rust 1.0 has now frozen the language to some extent.

Thanks for trying to explain, I appreciate it.

[steveklabnik]

They can be any data type; just a name, a struct, a tuple struct, or even another enum.

I think also, likewise, “union” sounds strange unless you have C experience. Many of our users do not know C, and so that name doesn’t help them either.

In the end names are hard.

Happy to, you’re very welcome :)

[roar-of-time]

C, or a little set theory. :)

[loeg]

> In the end names are hard.

Indeed! Thanks again.