Element-wise tuple addition

You could also consider using std::valarray since it allows exactly the things that you seem to want.

#include <valarray>

int main()
{
    std::valarray<int> a{ 1, 2 }, b{ 2, 4 }, c;
    c = a - b; // c is {-1,-2}
    a += b; // a is {3,6}
    a -= b; // a is {1,2} again
    a += {2, 4}; // a is {3,6} again
    return 0;
}