Yeah, basically whatever const_missing returns is considered to be the
value of the constant:

    class C
      def self.const_missing(*)
        1
      end
    end

    C::X # => 1
    C::Y # => 1

Rails uses const_missing to intercept unknown constants and load files on
demand based on naming conventions. In the case of Rails, if loading
succeeds the constant gets actually defined because the file that defines
it is interpreted. Thus, in Rails const_missing is triggered only once per
constant.