[rlp]

Include doesn't work for cyclic types, they need to be in the same "type" block. I do not agree with Araq's stance here, there are often cases when closely-related types need to reference each other, and it's not always convenient to put them in the same file. That's why you see the "types.nim" file in larger Nim projects -- no one has a good solution and just shoves them all together. And, if you use types.nim, you no longer have proper visibility control, since fields cannot be private and there is no package-level visibility. Most languages understand this, C/C++/Rust all allow at least the ability to forward declare a type (and Rust allows cyclic, out-of-order types).