tempconvert.rb

class Temperature < Numeric
  def initialize(temp)
    @temp = temp
    super
  end

  def to_farenheit
    9 / 5 * (@temp + 32)
  end
  
  def to_farenheit!
    @temp = 9 / 5 * (@temp + 32)
  end
  
  def to_celcius
    5 / 9 * (@temp - 32)
  end
  
  def to_celcius!
    @temp = 5 / 9 * (@temp - 32)
  end
end

=begin
doctest: From celcius to farenheit
>> Temperature.new(40).to_farenheits
=> 72
=end

=begin
doctest: From farenheit to celcius
>> Temperature.new(72).to_celcius
=> 40
=end

=begin
doctest: From celcius to farenheit permanent
>> temp = Temperature.new(40).to_farenheit!
>> temp
=> 72
=end

=begin
doctest: From farenheit to celcius permanent
>> temp = Temperature.new(72).to_celcius!
>> temp
=> 40
=end