  template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
    void launder(_Ret (*)(_Args...) _GLIBCXX_NOEXCEPT_QUAL) = delete;
  template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
    void launder(_Ret (*)(_Args......) _GLIBCXX_NOEXCEPT_QUAL) = delete;