Skip the isinstance check if a cast was used

[tmke8]

Hi, I have a (maybe unusual) situation where I do a cast but the result will not pass the isinstance check. A minimal example:

from dataclasses import dataclass
from typing import NewType
import dacite

UserId = NewType("UserId", int)

@dataclass
class Config:
    user_id: UserId

dacite.from_dict(data_class=Config, data={"user_id": 3}, config=dacite.Config(cast=[UserId]))

In this case, isinstance(user_id, UserId) will fail, because NewType has no effect at runtime (it's purely for static type checking).

I would argue that if a cast was performed, the user knows what they're doing and the isinstance check is not needed anyway.

If this sounds reasonable to you, I'd be happy to make the code changes and send a PR.

[tmke8]

Never mind actually. It does work if you don't do other weird things (like I did).