The following code example is taken from the book
C++ Templates - The Complete Guide, 2nd Edition
by David Vandevoorde, Nicolai M. Josuttis, and Douglas Gregor,
Addison-Wesley, 2017
© Copyright David Vandevoorde, Nicolai M. Josuttis, Douglas Gregor 2017
template<unsigned I, unsigned N, typename IndexList = Valuelist<unsigned>>
class ReplicatedIndexListT;
template<unsigned I, unsigned N, unsigned... Indices>
class ReplicatedIndexListT<I, N, Valuelist<unsigned, Indices...>>
: public ReplicatedIndexListT<I, N-1,
Valuelist<unsigned, Indices..., I>> {
};
template<unsigned I, unsigned... Indices>
class ReplicatedIndexListT<I, 0, Valuelist<unsigned, Indices...>> {
public:
using Type = Valuelist<unsigned, Indices...>;
};
template<unsigned I, unsigned N>
using ReplicatedIndexList = typename ReplicatedIndexListT<I, N>::Type;
template<unsigned I, unsigned N, typename... Elements>
auto splat(Tuple<Elements...> const& t)
{
return select(t, ReplicatedIndexList<I, N>());
}