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<typename Types, typename Indices>
class SelectT;
template<typename Types, unsigned... Indices>
class SelectT<Types, Valuelist<unsigned, Indices...>>
{
public:
using Type = Typelist<NthElement<Types, Indices>...>;
};
template<typename Types, typename Indices>
using Select = typename SelectT<Types, Indices>::Type;