message: Added overload of contains<> for tuple
diff: @@ -91,6 +91,9 @@ namespace detail
  template <typename T1, typename T2, typename... Ts>
  struct contains<T1, T2, Ts...> : std::integral_constant<bool, std::is_same<T1, T2>::value ||
  contains<T1, Ts...>::value> {};
  + template<typename T, typename... Types>
  + struct contains<T, std::tuple<Types...>> : std::integral_constant<bool, contains<T, Types...>::value> {};
  +
  template <typename...>
  struct all_unique : std::true_type{};
  