serif::equations::Contributions contributions.hpp typename T typename void std::tuple< T > using serif::equations::Contributions< T, typename >::type = std::tuple<T> type serif::equations::Contributions::type tuple of whatever is T Helper struct to pack a list of contributions into a tuple. This is used to define the set of contributions of an equation. T The type to pack into a tuple of contributions. This can be a single contribution or a tuple of contributions. serif::equations::Contributionstype