Rubyでクラスインスタンス変数にインスタンスメソッドからアクセス

class_instance_variable.rb

class C
	class << self
	  # proxy methods
		def class_instance_variable
			@class_instance_variable
		end
		def class_instance_variable=(other)
			@class_instance_variable = other
		end
	end
	@class_instance_variable = 12

	def get_class_instance_variable
		self.class.class_instance_variable
	end

	def set_class_instance_variable(other)
		self.class.class_instance_variable = other
	end
end

a = C.new
p a.get_class_instance_variable # => 12

b = C.new
p b.get_class_instance_variable # => 12

a.set_class_instance_variable(-44)
p a.get_class_instance_variable # => -44
p b.get_class_instance_variable # => -44