[rnestler]

> The real problem is that you can't use crates to improve incrementalism when you have a type in one logical part of the module hierarchy implement a trait from another logical part. Due to orphan rules and coherence, it is not possible to implement a foreign trait for a foreign type.

Well you can implement a trait for a type from another logical part either in the crate of the trait or the crate of the type.

What is the use-case for implementing a foreign trait for a foreign type if you have both under control?