Refinements on Ruby 2.0

gistfile1.rb

class String
  def say_hi
    "Hi #{self}!"
  end
end

class MinhaClasse
  puts "Pedro".say_hi
end

# Com o Refinments

module StringExtensions
  refine String do
    def say_hi
      "Hi #{self}!"
    end
  end
end

class MinhaClasse
  using StringExtensions
  
  puts "Pedro".say_hi
end