cooler redefine method

gistfile1.rb

class Object
  def redefine_method(meth)
    return unless block_given?
    oldmeth = self.instance_method(meth)
    self.send(:define_method, meth) {|*args|
      yield(oldmeth.bind(self), *args)
    }
  end
end

#=begin EXAMPLE

str = "cacca"

class String
  def puts
    STDOUT.puts self
  end
end

str.puts

class String
  redefine_method(:puts) {|old|
    STDOUT.print "Hi, i'm "
    old.call
  }
end

str.puts
#=end