from collections.abc import Callable
from typing import Generic, ParamSpec, Protocol, TypeVar

P = ParamSpec("P")
T = TypeVar("T")

class RPC(Generic[P, T]):
    def server(self) -> str: ...
    async def do_rpc(self, *args: P.args, **kwargs: P.kwargs) -> T: ...

class FirstAPIAttempt:
    my_rpc: RPC[[int, str], float]
    my_other_rpc: RPC[[float], float]

class FunctionBox(Generic[P, T]):
    def __init__(self, func: Callable[P, T]):
        self.func = func

def f(x: int, y: str) -> float: ...

fb = FunctionBox(f)
reveal_type(fb) # fb: FunctionBox[(x: int, y: str), float]

class SecondAPIAttempt:
    my_rpc: RPC[(x: int, y: str), float]
    my_other_rpc: RPC[(z: float), float]

class MyRPCSpec(Protocol):
    async def __call__(self, x: int, y: str) -> float: ...

class ThirdAPIAttempt:
    my_rpc: RPC[MyRPCSpec]