23 General utilities library [utilities]

23.5 Tuples [tuple]

23.5.3 Class template tuple [tuple.tuple]

23.5.3.5 Calling a function with a tuple of arguments [tuple.apply]

🔗
template <class F, class Tuple> constexpr decltype(auto) apply(F&& f, Tuple&& t);
1
#
Effects: Given the exposition-only function: 
template <class F, class Tuple, size_t... I>
constexpr decltype(auto)
    apply_impl(F&& f, Tuple&& t, index_sequence<I...>) {                // exposition only
  return INVOKE(std::forward<F>(f), std::get<I>(std::forward<Tuple>(t))...);
}
Equivalent to: 
return apply_impl(std::forward<F>(f), std::forward<Tuple>(t),
                  make_index_sequence<tuple_size_v<decay_t<Tuple>>>{});
🔗
template <class T, class Tuple> constexpr T make_from_tuple(Tuple&& t);
2
#
Effects: Given the exposition-only function: 
template <class T, class Tuple, size_t... I>
constexpr T make_from_tuple_impl(Tuple&& t, index_sequence<I...>) {     // exposition only
  return T(get<I>(std::forward<Tuple>(t))...);
}
Equivalent to: 
return make_from_tuple_impl<T>(forward<Tuple>(t),
                               make_index_sequence<tuple_size_v<decay_t<Tuple>>>{});
[ Note
:
The type of T must be supplied as an explicit template parameter, as it cannot be deduced from the argument list.
— end note
 ]