gistfile1.rb

class Object
  def metaclass
    (class << self; self; end)
  end
end

class Foo
  puts "1. #{self} #{self.__id__}" 
  
  def meth1
    puts "2. #{self} #{self.__id__}"   
  end
  
  def self.meth2
    puts "3. #{self} #{self.__id__}"                 
  end                                                
                                                     
  puts "4. #{self.metaclass} #{self.__id__}"        
                                                   
  def meth3                                         
    puts "5. #{self.metaclass} #{self.__id__}"      
  end
end

Foo.new.meth1
Foo.meth2
Foo.new.meth3
puts "6. #{Foo} #{Foo.__id__}"