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| #include <array>
#include <iostream>
#include <tuple>
#include <utility>
template <typename T, T... ints>
void print_sequence(std::integer_sequence<T, ints...> int_seq) {
std::cout << "" << int_seq.size() << ": ";
((std::cout << ints << ' '), ...);
std::cout << '\n';
}
template <typename Array, std::size_t... I>
auto a2t_impl(const Array& a, std::index_sequence<I...>) {
return std::make_tuple(a[I]...);
}
template <typename T, std::size_t N,
typename Indices = std::make_index_sequence<N>>
auto a2t(const std::array<T, N>& a) {
return a2t_impl(a, Indices{});
}
template <class Ch, class Tr, class Tuple, std::size_t... Is>
void print_tuple_impl(std::basic_ostream<Ch, Tr>& os, const Tuple& t,
std::index_sequence<Is...>) {
((os << (Is == 0 ? "" : ", ") << std::get<Is>(t)), ...);
}
template <class Ch, class Tr, class... Args>
auto& operator<<(std::basic_ostream<Ch, Tr>& os, const std::tuple<Args...>& t) {
os << "(";
print_tuple_impl(os, t, std::index_sequence_for<Args...>{});
return os << ")";
}
int main() {
print_sequence(std::integer_sequence<unsigned, 9, 2, 5, 1, 9, 1, 6>{});
print_sequence(std::make_integer_sequence<int, 20>{});
print_sequence(std::make_index_sequence<10>{});
print_sequence(std::index_sequence_for<float, std::iostream, char>{});
std::array<int, 4> array = {1, 6, 3, 4};
auto tuple = a2t(array);
static_assert(std::is_same<decltype(tuple), std::tuple<int, int, int, int>>::value, "");
std::cout << tuple <<'\n';
system("pause");
}
|