arr = [1, 2, 3, 4, 5]

# *** before: ***
tail_old = arr[2..-1]

# *** in version 2.6: ***
tail = arr[2..]                              # an endless Range, reads to the end
first_evens = (1..).lazy.select(&:even?).first(3)

puts tail.inspect
puts first_evens.inspect