Support for multiple return values in Ruby 1.9, the way Common Lisp does it… sort of

multi_value.rb

class MultiValue < BasicObject
  attr_reader :secondary

  def initialize(obj, *secondary)
    @obj, @secondary = obj, secondary
  end

  def method_missing(sym, *args, &block)
    @obj.__send__(sym, *args, &block)
  end
end

class Array
  def to_mv
    MultiValue.new(*self) unless empty?
  end
end

class Numeric
  def floor_with_remainder
    [floor, remainder(floor)].to_mv
  end
end

Common Lisp functions can return multiple values:

(floor pi)
; 3 ;
; 0.14159265358979323851L0

Conveniently, functions that return multiple values are treated,
by default, as though only the first value was returned:

(+ (floor pi) 2)
; => 5

Now we can do the following in Ruby:

Math::PI.floor_with_remainder + 2
# => 5

mv = Math::PI.floor_with_remainder
mv.secondary.inject(mv, :+)
# => 3.141592653589793