ruby継承

inheritance.rb

module Hoge
  class Fuga
  end
end

module Hoge
  module Fuga
    class Piyo
    end
  end
end

class Foo < Hoge::Fuga::Piyo
end

#$ ruby hoge.rb
# hoge.rb:7:in `<module:Hoge>': Fuga is not a module (TypeError)
# 	from hoge.rb:6:in `<main>'