gistfile1.cpp

// Termination case (A, B) -> std::pair<A,B>
template <typename LhsTy, typename RhsTy>
std::pair<LhsTy,RhsTy> makeTree(const LhsTy& lhs, const RhsTy& rhs) { 
  return {lhs, rhs}; 
}

template <typename Arg1, typename Arg2, typename Arg3, typename... Args>
auto makeTree(const Arg1& arg1, const Arg2& arg2, const Arg3& arg3, const Args&... args) -> ???
{
  return {arg1, makeTree(arg2,arg3,args...)};
}