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
#include <iostream>
void printTuple(std::ostream& strm, Tuple<> const&, bool isFirst = true)
{
strm << ( isFirst ? '(' : ')' );
}
template<typename Head, typename... Tail>
void printTuple(std::ostream& strm, Tuple<Head, Tail...> const& t,
bool isFirst = true)
{
strm << ( isFirst ? "(" : ", " );
strm << t.getHead();
printTuple(strm, t.getTail(), false);
}
template<typename... Types>
std::ostream& operator<<(std::ostream& strm, Tuple<Types...> const& t)
{
printTuple(strm, t);
return strm;
}