Enumerable#peek_at an index.

peek_at.rb

module Enumerable
  def peek_at index
    value, _ = each_with_index.select { |_, i| index == i }.first
    value
  end
end

peek_at_examples.rb

['a', 'b', 'c'].peek_at 2
#=> "c"

'a'.upto('c').peek_at 2
#=> "c"

('a'..'c').peek_at 2
#=> "c"

Struct.new(:a, :b, :c).new('a', 'b', 'c').peek_at 2
#=> "c"

{a: 'a', b: 'b', c: 'c'}.peek_at 2
#=> [:c, "c"]

peek_at_so_slow.rb

require 'era'

time(100_000) { ['a', 'b', 'c'].peek_at 2 }
# Elapsed time: 189.518 ms
#=> "c"

time(100_000) { ['a', 'b', 'c'][2] }
# Elapsed time: 36.828 ms
#=> "c"