peek_values

        # Enumerator.peek_values

(from ruby core)
---
    e.peek_values   -> array

---

Returns the next object as an array, similar to Enumerator#next_values,
but doesn't move the internal position forward.  If the position is
already at the end, StopIteration is raised.

See class-level notes about external iterators.

### Example

    o = Object.new
    def o.each
      yield
      yield 1
      yield 1, 2
    end
    e = o.to_enum
    p e.peek_values    #=> []
    e.next
    p e.peek_values    #=> [1]
    p e.peek_values    #=> [1]
    e.next
    p e.peek_values    #=> [1, 2]
    e.next
    p e.peek_values    # raises StopIteration