from collections.abc import Iterable, Iterator


def smart_iter[T](
    iterable: Iterable[T], *, start: int = 0
) -> Iterator[tuple[int, bool, T]]:
    it = iter(iterable)
    num = start
    try:
        current = next(it)
    except StopIteration:
        return
    for next_item in it:
        yield num, False, current
        current = next_item
        num += 1
    yield num, True, current