message: das.named: rely on return-type deduction
diff: @@ -45,11 +45,9 @@ namespace das
  List<Remaining...>,
  List<>>
  {
  - template <typename F>
  - using result_of = std::result_of_t<F&(Remaining..., Applied...)>;
  template <typename F>
  static
  - result_of<F>
  + auto
  apply(DefaultStore&,
  F const& f,
  Applied&& ... applied,
  @@ -79,11 +77,9 @@ namespace das
  List<Applied..., typename RHead::Passing>,
  List<Store..., RTail...>,
  List<>>;
  - template <typename F>
  - using result_of = typename next::template result_of<F>;
  template <typename F>
  static
  - result_of<F>
  + auto
  apply(DefaultStore& defaults,
  F const& f,
  Applied&& ... applied,
  @@ -123,11 +119,9 @@ namespace das
  List<Applied...>,
  List<RTail...>,
  List<Store..., RHead>>;
  - template <typename F>
  - using result_of = typename next::template result_of<F>;
  template <typename F>
  static
  - result_of<F>
  + auto
  apply(DefaultStore& defaults,
  F const& f,
  Applied&& ... applied,
  @@ -163,11 +157,9 @@ namespace das
  List<Applied..., StoreHead&&>,
  List<StoreTail...>,
  List<>>;
  - template <typename F>
  - using result_of = typename next::template result_of<F>;
  template <typename F>
  static
  - result_of<F>
  + auto
  apply(DefaultStore& defaults,
  F const& f,
  Applied&& ... applied,
  @@ -208,11 +200,9 @@ namespace das
  List<Applied..., typename default_type::Passing>,
  List<Store...>,
  List<>>;
  - template <typename F>
  - using result_of = typename next::template result_of<F>;
  template <typename F>
  static
  - result_of<F>
  + auto
  apply(DefaultStore& defaults,
  F const& f,
  Applied ... applied,
  @@ -318,11 +308,7 @@ namespace das
  {}
  template <typename F, typename ... Args>
  - typename Applier<DefaultStore,
  - List<typename make_formal<Formal>::type...>,
  - List<>,
  - List<Args...>,
  - List<>>::template result_of<F>
  + auto
  call(F const& f, Args&& ... args) const
  {
  ELLE_LOG_COMPONENT("das.named");
  