Arithmetic on all but the last components of tuples in C++

Getting inspiration from this question, I managed to implement a function which takes two tuples as input and return a tuple which components are the min of each components of the tuples given in input.

template<typename T, T...>  struct integer_sequence { };    template<std::size_t N, std::size_t... I>  struct gen_indices : gen_indices<(N - 1), (N - 1), I...> { };  template<std::size_t... I>  struct gen_indices<0, I...> : integer_sequence<std::size_t, I...> { };    template <typename ... T, std::size_t ... I>  std::tuple<T...> min_tuple_impl(          const std::tuple<T...>& t1,          const std::tuple<T...>& t2,          integer_sequence<std::size_t, I...>)  {      return { (std::min(std::get<I>(t1), std::get<I>(t2)))... };  }    template <typename ... T>  std::tuple<T...> min_tuple(          const std::tuple<T...>& t1,          const std::tuple<T...>& t2)  {      return min_tuple_impl(t1, t2, gen_indices<sizeof...(T)>{});  }    

Now, I would like it to work on all components but the last one.

std::tuple<int, int, int> t1 {10, 20, 30}  std::tuple<int, int, int> t2 {15, 15, 15}  min_tuple(t1, t2) // == {10, 15, 30}, for the last one, always keep the component of t1  

How could I get this in C++11?

https://stackoverflow.com/questions/67426161/arithmetic-on-all-but-the-last-components-of-tuples-in-c May 07, 2021 at 05:26AM