My way to convert decimal to hexadecimal and vice versa in Ruby

gistfile1.rb

class Fixnum
  def to_hex
    self.to_s 16
  end
end

class String
  def to_i_from_hex
    self.to_i 16
  end
  
  alias :from_hex :to_i_from_hex
end

puts 30.to_hex # "1e"

puts '1e'.to_i_from_hex # 30