Why in Ruby Object's singleton_class isn't Class?-CodePudding

I am a little confused, why is the super class of the singleton class using is_a? method but return false?

class Animal
end

obj = Animal.new
singleton = (class<<obj;self;end)

p singleton.ancestors , singleton.is_a?(Animal) 

#[#<Class:#<Animal:0x00000000060105d0>>, Animal, Object, Kernel, BasicObject]
#false

I think it shall return true.

Experienced experts please help me

CodePudding user response：

You are asking whether the singleton class is an animal. But the singleton class is not an animal, it is a class, i.e. it is an instance of the Class class, not the Animal class.

This is no different from any other class. For example 1 is an instance of Integer, but Integer is not an instance of Numeric, it is an instance of Class. Integer.is_a?(Numeric) would be false, since Integer is not an instance of Numeric, it is a subclass of Numeric.