from typing import Awaitable, Callable, TypeVar R = TypeVar("R") def add_logging(f: Callable[..., R]) -> Callable[..., Awaitable[R]]: async def inner(*args: object, **kwargs: object) -> R: await log_to_database() return f(*args, **kwargs) return inner @add_logging def takes_int_str(x: int, y: str) -> int: return x + 7 await takes_int_str(1, "A") await takes_int_str("B", 2) # fails at runtime