Pre-RFC: Using existing structs and tuple-structs as enum variants

language design
25

With type ascription in patterns appearing plausibly-going-to-happen, I more than ever think that this is the right way for this to be consumed:

match x {
    y: Ipv4Addr => ...,
    z: Ipv6Addr => ...,
}

I don’t know the rest of the design, though :slightly_smiling_face:

Perhaps the answer is that if the types are the same, it runs the first matching arm – like it would if you translated it into a sequence of downcasts off an any. And yes, that means you can’t use it place of Result, but I think that’s fine in same way you can’t tell the difference between (r, g, b) and (x, y, z) in tuples the way you can between { r, g, b } and { x, y, z } in structs.

Ideas around anonymous enum types
Concept RFC: Tuple Enums