Shane F. Carr

@ben-allen to sync with @ptomato and coordinate on a PR.

That's right; we have a lot of issues open regarding [User Preferences](https://github.com/tc39/ecma402/issues?q=is%3Aissue%20state%3Aopen%20label%3A%22User%20Preferences%22) that differ from locale defaults. You found #370 for adding the `-u-rg` keyword, which behaves the way you...

Conclusion: - have each type have two constructors (C++ names, ABI names TBD): `create` and `create_with_provider` - `DataProvider(Box)`, the other variants are useless - `enable_locale_fallback` can either load from itself...

With the `#[methodversion]` attribute in #3790, we can now make these be simply - Rust: `ListFormatter::create()`, `ListFormatter::create_with_provider(DataProvider)` - ABI: `icu4x_list_ListFormatter_create_mv1`, `icu4x_list_ListFormatter_create_with_provider_mv1(DataProvider)` - C++: we are allowed to break across major...

@robertbastian What is to do here?