Documentation for method count-only, assembled from the following types:
By default is not implemented, but expected implementation for types that do this role is:
method count-only(--> Int)
The method returns the number of elements the
Iterator can still produce. Important: it's expected the
Iterators that implement this method can produce that number without exhausting themselves. In other words, it's expected the user of the class will be able to still pull-one after calling this method, and eventually receive as many items as the return value of this method indicated.