define_method + super in refinements

gistfile1.rb

# ruby version: ruby 2.0.0dev (2012-12-01 trunk 38126)
END{
  using Test
  p '123'.to_i    # => 123 - ok
  p '123'.size    # => 3 - works! 
  p '123'.inspect # => error
}

module Test
  refine String do
    def to_i
      super.to_s + ' - ok'
    end

    define_method :size do 
      unwrap(self).size.to_s + ' - works!'
    end    

    define_method :inspect do 
      super() + ' - stack level too deep (SystemStackError)'
    end
  end
end

# to call method out of refinement scope
class Unwrapped < BasicObject
  def initialize obj; @obj = obj end
  private; attr_reader :obj
  def method_missing *a,&b; obj.send *a,&b end # fixed
end
def unwrap(object)
  Unwrapped.new object
  # require 'object-proxy'
  # OP::proxy(object)
end