template <typename Function, typename InputIt, typename... InputIts>
constexpr inline Function for_eachs(Function f, InputIt first, InputIt last, InputIts... firsts);
template <typename Function, typename InputIt, typename Size, typename... InputIts>
constexpr inline InputIt for_eachs_n(Function f, InputIt first, Size n, InputIts... firsts);
These functions are similar to multidim::for_each and multidim::for_each_n, but allow multiple sequences to be iterated together. For for_eachs, std::distance(first, last) determines the number of applications of f; for for_eachs_n, n determines the number of applications of f.
f - function object, which must be callable as f(*it, (*its)...), where it has type InputIt and its... has type InputIts....
template <typename Function, typename InputIt, typename... InputIts>
constexpr inline Function for_eachs(Function f, InputIt first, InputIt last, InputIts... firsts) {
for (; first != last; ++first, ((++firsts), ...)) {
f(*first, (*firsts)...);
}
return f;
}
template <typename Function, typename InputIt, typename Size, typename... InputIts>
constexpr inline InputIt for_eachs_n(Function f, InputIt first, Size n, InputIts... firsts) {
for (Size i = 0; i < n; ++i, ++first, ((++firsts), ...)) {
f(*first, (*firsts)...);
}
return first;
}