tuple0.hpp

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>
class Tuple;

// recursive case:
template<typename Head, typename... Tail>
class Tuple<Head, Tail...>
{
 private:
  Head head;
  Tuple<Tail...> tail;
 public:
  // constructors:
  Tuple() {
  }
  Tuple(Head const& head, Tuple<Tail...> const& tail)
    : head(head), tail(tail) {
  }
  //...

  Head& getHead() { return head; }
  Head const& getHead() const { return head; }
  Tuple<Tail...>& getTail() { return tail; }
  Tuple<Tail...> const& getTail() const { return tail; }
};

// basis case:
template<>
class Tuple<> {
  // no storage required
};