What about creating a new syntax for annotating metadata? For example,
`type_hint :: metadata` could be equivalent to `Annotated[type_hint,
"metadata"]`, and if we wanted type guards to look like TypeScript they could
look like this:
```
def is_str_list(val: List[object]) -> bool :: is
I'd like to chime in with an example of how PEP 563 breaks code that uses
dataclasses.
I've written a library instant_api (https://github.com/alexmojaki/instant_api)
that is heavily inspired by FastAPI but uses dataclasses for complex types
instead of pydantic. The example at the beginning of
