A Set class that rejects nil

no_nil_set.rb

require 'set'

class NoNilSet
  include Enumerable
  
  def initialize(values=[])
    @set = Set.new
    @set += Array(values).compact
  end

  def +(other)
    self.class.new(@set + other.compact)
  end
  
  def <<(value)
    @set << value unless value.nil?
    self
  end
  
  def compact
    self
  end
  
  def each(&block)
    @set.each(&block)
  end
end


s = NoNilSet.new [1, 2, :foo, nil, false]
t = NoNilSet.new [1, :bar]
s += t
s << nil
s += [nil]

p s
# => #<NoNilSet:0x007fbf22142330 @set=#<Set: {1, 2, :foo, false, :bar}>>