The Hashtable Problem: A Litmus Test for External Impl Proposals

It's a good pattern for e.g. ordered containers I think, but it wouldn't solve the newtype pain points that external trait impls would cover: rust-rfcs/text/3634-scoped-impl-trait-for-type.md at 251e4c443757ebe7c079a8a3627e32f9b79d4d0e · Tamschi/rust-rfcs · GitHub Implementing it for everything that takes bounded generics also seems very noisy to me in terms of API surface.