money.rb

module Mongoid
  class << self
    def Money(value)
      Money.create_from_value(value)
    end
  end

  class Money
    class << self
      def create_from_value(value)
        self.new(value)
      end
    end

    def initialize(value)
      @sign = value.to_f < 0 ? -1 : 1
      exp_pos = value.to_s =~ /\./
      @exp = if exp_pos.nil?
        0
      else
        value.to_s.size - (exp_pos + 1)
      end
      @number = (value.to_f * (10**@exp)).to_i
    end

    def to_f
      (@sign * (@number.to_f / (10**@exp))).to_f
    end

    def precision
      @exp
    end
  end
end