Element-wise tuple addition

Question

I have some values held in a tuple, and I am looking to add another tuple to it element-wise. So I would like functionality like this:

std::tuple         


        

Answer 1

The solution by @lubgr is satisfactory for your specific use-case. I offer you a generic solution which will work for tuples of different types, as well tuples of different (equal) sizes.

#include 
#include 
#include 

template
constexpr auto add(const std::tuple& t1, const std::tuple& t2, 
                   std::index_sequence)
{
    return std::tuple{ std::get(t1) + std::get(t2)... };
}

template
constexpr auto operator+(const std::tuple& t1, const std::tuple& t2)
{
    // make sure both tuples have the same size
    static_assert(sizeof...(T1) == sizeof...(T2));

    return add(t1, t2, std::make_index_sequence{});
}

I used a few C++17 features (mainly template-related) without which the code would become a bit more complicated. A possible improvement would be to make use of move-semantics.

Obviously, this applies for the first "possible syntax" you provided.