Ruby - 對象是否可以訪問或標識實例化它的對象？

Question

例如，我怎麼能實現以下功能

class A 
    def initialize 
    b = B.new 
    end 
end 

class B 
    def initialize 
    puts #how can I find out who instantiated me 
    end 
end 

Answer 1

class A 
    def initialize 
    B.new(self) 
    end 
end 

class B 
    def initialize initializer 
    puts initializer 
    end 
end 

A.new # => #<A:0x007fee78368dc8>