Add example of overload with default values about cpython

[JelleZijlstra]

We don't change old PEPs. New examples should either be added to the CPython documentation (in this case, Doc/library/typing.rst) or the typing spec in https://github.com/python/typing.

[nineteendo]

Do we add it to the PEP, or do we modify the example in the docs?

@overload
def process(response: None) -> None:
    ...
@overload
def process(response: int) -> tuple[int, str]:
    ...
@overload
def process(response: bytes) -> str:
    ...
def process(response):
    ...  # actual implementation goes here

[davidlowryduda]

Do we add it to the PEP, or do we modify the example in the docs?

It's not necessary to write a PEP for this. If you know where you think an example would fit well in the docs, then you can make a pull request with that change. Each pull request should typically cite an issue, and this issue would be a good issue to cite.

[nineteendo]

No, not a new PEP, I meant adding it to the other examples in the existing PEP: https://peps.python.org/pep-0484/#function-method-overloading.

[nineteendo]

I suggest we modify the example like this:

@overload
def process(response: None = ...) -> None:
    ...
@overload
def process(response: int) -> tuple[int, str]:
    ...
@overload
def process(response: bytes) -> str:
    ...
def process(response=None):
    ...  # actual implementation goes here

Should we mention overlap as well?

@overload
def unsafe_func(x: int = ...) -> int:
    ...
@overload
def unsafe_func(x: str = ...) -> str:
    ...
def unsafe_func(x = "abc"):
    return x

[nineteendo]

Do we close this or not? You rejected both my pull requests.

[JelleZijlstra]

Yes, I don't think there's anything to do here for CPython.