Integer#multiple_of?

gistfile1.rb

class Numeric
  def multiple_of?(*numbers)
    zero? || numbers.all? { |n| n.nonzero? && modulo(n).zero? }
  end
end

if $0 == __FILE__
  require 'test/unit'
  
  class MultipleOfTest < Test::Unit::TestCase
    def test_multiple_of
      assert 0.multiple_of?(1)
      assert 0.0.multiple_of?(1)
      assert 0.multiple_of?(2)
      assert 0.multiple_of?(0)
      assert !0.1.multiple_of?(0)
  
      assert 1.multiple_of?(1)
      assert 1.0.multiple_of?(1)
      assert !1.multiple_of?(0)
      assert !1.multiple_of?(2)
  
      assert 2.multiple_of?(1, 2)
      assert !2.multiple_of?(1, 2, 3)
    end
  end
end