I'd like to propose a new method for Enumerator which returns whether there will be a next value in the enumerator when calling `Enumerator#next`. `next`. It should work like this ruby demo: ~~~ ruby class Enumerator def next? begin peek rescue StopIteration return false end true end end a = [1,2,3] e = a.to_enum p e.next? #=> true p e.next #=> 1 p e.next? #=> true p e.next #=> 2 p e.next? #=> true p e.next #=> 3 p e.next? #=> false p e.next #raises StopIteration ~~~ I propose the method to be called `next?` as it returns either `true` or `false`. I am aware that we can currently figure out if there is a next value by using `rescue` (as in the code snippet above), but it is ugly since it covers many lines and uses exceptions for control flow. Introducing the `next?` method makes enumerators a little nicer to work with. A patch with an example implementation for ruby trunk is attached (in git-diff format, any feedback welcome). I agree that my patch will be licensed under the Ruby License.