How to define a type constraint for any channel type

I'm trying to define a funcion that returns the percentage of usage of a given channel:

func ChannelUsagePct[T any](channel chan T) int {
	channelCap := cap(channel)
	channelLen := len(channel)
	if channelCap == 0 {
		// Unbuffered channel
		return 0
	}
	return 100 * channelLen / channelCap
}
func main() {
	twoWayChannel := make(chan int, 10)
	var sendOnlyChannel chan<- int = twoWayChannel
	var recvOnlyChannel <-chan int = twoWayChannel
	fmt.Println(ChannelUsagePct(twoWayChannel))
	fmt.Println(ChannelUsagePct(sendOnlyChannel)) // Does not work 
	fmt.Println(ChannelUsagePct(recvOnlyChannel))  // Does not work 
}

Now the thing is that this works for the first channel but not for the second and third, without changing the func's signature. But if I change the signature, I need to either choose the channel to be receive only, or send only. Is there a way to define a channel that is zero-way? E.g. cannot be read nor written to, I just want to use cap and len funcs on it.
Ideally the ChannelUsagePct should work for any of the 3 cases.

In order to allow all three possible forms of a channel, a separate type constraint needs to be defined.

type Chan[T any] interface {
	chan T | <-chan T | chan<- T
}

This will require instantiating the type constraint with the type of T when it's used, which can be done with another type parameter:

func Cap[T any, C Chan[T]](c C) int {
	return cap(c)
}

Because of that instantiation the entire type cannot be inferred, but only the channel element type needs to be supplied:

ch := make(chan int, 3)
i := Cap[int](ch)
fmt.Println(i)
// 3

https://go.dev/play/p/1lx5R4MFvFx