check7107.rb

module Foo
  C1 = 1
  class << self
    C2 = 2
    ::IFoo = self
  end
end
module Bar
  C3 = 3
  class << Foo
    C4 = 4
    def hoge
      [defined?(C1), defined?(C2), defined?(C3), defined?(C4)].map {|b| b ? 1 : 0}.join
    end
    define_method(:fuga) do
      [defined?(C1), defined?(C2), defined?(C3), defined?(C4)].map {|b| b ? 1 : 0}.join
    end
  end
  def Foo.piyo
    [defined?(C1), defined?(C2), defined?(C3), defined?(C4)].map {|b| b ? 1 : 0}.join
  end
  IFoo.send(:define_method, :hogera) do
    [defined?(C1), defined?(C2), defined?(C3), defined?(C4)].map {|b| b ? 1 : 0}.join
  end
end

p [Foo.hoge, Foo.fuga, Foo.piyo, Foo.hogera]
mod = Foo.dup
p [mod.hoge, mod.fuga, mod.piyo, mod.hogera]

# ruby 1.8.7 (2012-02-08 patchlevel 358) [x86_64-linux]
# ["0111", "0111", "0010", "0010"]
# ["1010", "0111", "1000", "0010"]

# ruby 1.9.3p194 (2012-04-20 revision 35410) [x86_64-linux]
# ["0111", "0111", "0010", "0010"]
# ["0111", "0111", "0101", "0010"]