Klasa szyn << self

module Utility

 class Options #:nodoc:

 class << self

 # we are inside Options's singleton class

 def parse(args) end

 end

 end

end

module Utility

 class Options #:nodoc:

 def Options.parse(args) end

 end

end

class A

 HELLO = 'world'

 def self.foo

 puts "class method A::foo, HELLO #{HELLO}"

 end def A.bar

 puts "class method A::bar, HELLO #{HELLO}"

 end class << self

 HELLO = 'universe'

 def zim

 puts "class method A::zim, HELLO #{HELLO}"

 end

 endend

A.foo

A.bar

A.zim

puts "A::HELLO #{A::HELLO}"# Output

# class method A::foo, HELLO world

# class method A::bar, HELLO world

# class method A::zim, HELLO universe

# A::HELLO world