# this code works
list = (0..20).to_a
# => [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20] 
 
odd = list.select { |x| x.odd? }
# => [1,19] 
 
list.reject! { |x| x.odd? }
# => [0,20] 
 
# but can i emulate this type of functionality with an enumerable method?
set = [1,10]
# => [1,10] 
one,five,ten = set
# => [1,10] 
one
# => 1 
five
# => 5 
ten
# => 10
 
# ------------------------------------------------
# method I am looking for ?
list = (0..20).to_a
odd,even = list.select_with_reject { |x| x.odd? }
# put the matching items into the first variable
# and the non-matching into the second