Allow accessing / retrieving the current item of `itertools.count`

[dg-pb]

@jamestwebber

I was mostly reacting to the fact that there is definitely something “micro” about microseconds.

This is why I multiplied it.

@jamestwebber

So a 1 µs speedup per iteration saves you… 0.1 seconds?

What about… I am processing CD quality audio with buffer size 64…

No, but seriously 1µs per iteration just to track the count of number of items processed is a lot.