template <class T> constexpr auto operator--(T & lhs) -> std::enable_if_t<stlab::implementation::has_enabled_arithmetic<T>, T &> (1) template <class T> constexpr auto operator--(T & lhs, int) -> std::enable_if_t<stlab::implementation::has_enabled_arithmetic<T>, T> (2) (1) template <class T> constexpr auto operator--(T & lhs) -> std::enable_if_t<stlab::implementation::has_enabled_arithmetic<T>, T &> MISSING Parameters T & lhs (2) template <class T> constexpr auto operator--(T & lhs, int) -> std::enable_if_t<stlab::implementation::has_enabled_arithmetic<T>, T> MISSING Parameters T & lhs int unnamed