Something strange happened here (or maybe the comment was deleted), but here is an interesting note to make: because of how NamedTuple behaves at runtime (just making a collectios.namedtuple) it implements corresponding protocols already at the class level, for example:

@runtime
class P(Protocol):
    x: int
class N(NamedTuple):
    x: int

assert issubclass(N, P)  # OK

I left a comment that I realized was completely incorrect so I deleted it

I will soon make another PR that will add (simplified) Protocol to typing_extensions. We cannot add
all the functionality while Protocol will be in typing_extensions since several classes (like SupportsInt etc.) subclass _Protocol in typing, ideally they should subclass the new Protocol, this is however quite minor thing.

I will keep this PR open (and update depending on the outcome of experiments with typing_extensions).

So IIUC we should first merge #464 and defer this one until the PEP has been accepted, right?

So IIUC we should first merge #464 and defer this one until the PEP has been accepted, right?

Yes, also if there will be something we discover while playing with typing_extensions, I will update this PR accordingly (actually there are already few minor tweaks that I need to make here following the review of #464).

This was superseded by #649