Ruby private class method -

i tried implement singleton pattern in ruby, want know why can not access private class method in ruby

class test      private_class_method :new     @@instance = nil     def self.getinstance             if(!@@instance)                     @@instance = test.new             end              return @@instance     end end 

i declare "new" private class method, , try call "new" in singleton method "getinstance"

test output

>> require "./test.rb" => true >> test.getinstance nomethoderror: private method `new' called test:class ./test.rb:7:in `getinstance' (irb):2 >>  

since ::new private method, can't access sending message class constant. it'll work send implicit self omitting receiver, though.

additionally, since class method, instance variable scope class-level, don't need use @@ class variables. instance variable work fine here.

class test   private_class_method :new    def self.instance     @instance ||= new   end end   puts test.instance.object_id puts test.instance.object_id # => 33554280 # => 33554280