_Parent* _M_parent = nullptr;
- // XXX: _M_current is present only if "V models forward_range"
[[no_unique_address]]
__detail::__maybe_present_t<forward_range<_Vp>,
iterator_t<_Base>> _M_current;
_Vp _M_base = _Vp();
_Pattern _M_pattern = _Pattern();
- // XXX: _M_current is "present only if !forward_range<V>"
[[no_unique_address]]
__detail::__maybe_present_t<!forward_range<_Vp>,
__detail::__non_propagating_cache<iterator_t<_Vp>>> _M_current;
: _M_base(std::move(__r))
{ }
- /* XXX: LWG 3280 didn't remove this constructor, but I think it should?
- template<viewable_range _Range>
- requires (!common_range<_Range>)
- && constructible_from<_Vp, views::all_t<_Range>>
- constexpr explicit
- common_view(_Range&& __r)
- : _M_base(views::all(std::forward<_Range>(__r)))
- { }
- */
-
constexpr _Vp
base() const& requires copy_constructible<_Vp>
{ return _M_base; }
_Iterator() requires default_initializable<iterator_t<_Base>> = default;
constexpr explicit
- _Iterator(iterator_t<_Base> current)
- : _M_current(std::move(current))
+ _Iterator(iterator_t<_Base> __current)
+ : _M_current(std::move(__current))
{ }
constexpr
- _Iterator(_Iterator<!_Const> i)
+ _Iterator(_Iterator<!_Const> __i)
requires _Const && convertible_to<iterator_t<_Vp>, iterator_t<_Base>>
- : _M_current(std::move(i._M_current))
+ : _M_current(std::move(__i._M_current))
{ }
constexpr const iterator_t<_Base>&
inline constexpr auto values = elements<1>;
} // namespace views
+#if __cplusplus > 202002L
+ namespace __detail
+ {
+ template<typename... _Rs>
+ concept __zip_is_common = (sizeof...(_Rs) == 1 && (common_range<_Rs> && ...))
+ || (!(bidirectional_range<_Rs> && ...) && (common_range<_Rs> && ...))
+ || ((random_access_range<_Rs> && ...) && (sized_range<_Rs> && ...));
+
+ template<typename... _Ts>
+ struct __tuple_or_pair
+ { using type = std::tuple<_Ts...>; };
+
+ template<typename _Tp, typename _Up>
+ struct __tuple_or_pair<_Tp, _Up>
+ { using type = pair<_Tp, _Up>; };
+
+ template<typename... _Ts>
+ using __tuple_or_pair_t = typename __tuple_or_pair<_Ts...>::type;
+
+ template<typename _Fp, typename _Tuple>
+ constexpr auto
+ __tuple_transform(_Fp&& __f, _Tuple&& __tuple)
+ {
+ return std::apply([&]<typename... _Ts>(_Ts&&... __elts) {
+ return __tuple_or_pair_t<invoke_result_t<_Fp&, _Ts>...>
+ (std::__invoke(__f, std::forward<_Ts>(__elts))...);
+ }, std::forward<_Tuple>(__tuple));
+ }
+
+ template<typename _Fp, typename _Tuple>
+ constexpr void
+ __tuple_for_each(_Fp&& __f, _Tuple&& __tuple)
+ {
+ std::apply([&]<typename... _Ts>(_Ts&&... __elts) {
+ (std::__invoke(__f, std::forward<_Ts>(__elts)), ...);
+ }, std::forward<_Tuple>(__tuple));
+ }
+ } // namespace __detail
+
+ template<input_range... _Vs>
+ requires (view<_Vs> && ...) && (sizeof...(_Vs) > 0)
+ class zip_view : public view_interface<zip_view<_Vs...>>
+ {
+ tuple<_Vs...> _M_views;
+
+ template<bool> class _Iterator;
+ template<bool> class _Sentinel;
+
+ public:
+ zip_view() = default;
+
+ constexpr explicit
+ zip_view(_Vs... __views)
+ : _M_views(std::move(__views)...)
+ { }
+
+ constexpr auto
+ begin() requires (!(__detail::__simple_view<_Vs> && ...))
+ { return _Iterator<false>(__detail::__tuple_transform(ranges::begin, _M_views)); }
+
+ constexpr auto
+ begin() const requires (range<const _Vs> && ...)
+ { return _Iterator<true>(__detail::__tuple_transform(ranges::begin, _M_views)); }
+
+ constexpr auto
+ end() requires (!(__detail::__simple_view<_Vs> && ...))
+ {
+ if constexpr (!__detail::__zip_is_common<_Vs...>)
+ return _Sentinel<false>(__detail::__tuple_transform(ranges::end, _M_views));
+ else if constexpr ((random_access_range<_Vs> && ...))
+ return begin() + iter_difference_t<_Iterator<false>>(size());
+ else
+ return _Iterator<false>(__detail::__tuple_transform(ranges::end, _M_views));
+ }
+
+ constexpr auto
+ end() const requires (range<const _Vs> && ...)
+ {
+ if constexpr (!__detail::__zip_is_common<const _Vs...>)
+ return _Sentinel<true>(__detail::__tuple_transform(ranges::end, _M_views));
+ else if constexpr ((random_access_range<const _Vs> && ...))
+ return begin() + iter_difference_t<_Iterator<true>>(size());
+ else
+ return _Iterator<true>(__detail::__tuple_transform(ranges::end, _M_views));
+ }
+
+ constexpr auto
+ size() requires (sized_range<_Vs> && ...)
+ {
+ return std::apply([](auto... sizes) {
+ using _CT = __detail::__make_unsigned_like_t<common_type_t<decltype(sizes)...>>;
+ return ranges::min({_CT(sizes)...});
+ }, __detail::__tuple_transform(ranges::size, _M_views));
+ }
+
+ constexpr auto
+ size() const requires (sized_range<const _Vs> && ...)
+ {
+ return std::apply([](auto... sizes) {
+ using _CT = __detail::__make_unsigned_like_t<common_type_t<decltype(sizes)...>>;
+ return ranges::min({_CT(sizes)...});
+ }, __detail::__tuple_transform(ranges::size, _M_views));
+ }
+ };
+
+ template<typename... _Rs>
+ zip_view(_Rs&&...) -> zip_view<views::all_t<_Rs>...>;
+
+ template<typename... _Views>
+ inline constexpr bool enable_borrowed_range<zip_view<_Views...>>
+ = (enable_borrowed_range<_Views> && ...);
+
+ namespace __detail
+ {
+ template<bool _Const, typename... _Vs>
+ concept __all_random_access
+ = (random_access_range<__maybe_const_t<_Const, _Vs>> && ...);
+
+ template<bool _Const, typename... _Vs>
+ concept __all_bidirectional
+ = (bidirectional_range<__maybe_const_t<_Const, _Vs>> && ...);
+
+ template<bool _Const, typename... _Vs>
+ concept __all_forward
+ = (forward_range<__maybe_const_t<_Const, _Vs>> && ...);
+
+ template<bool _Const, typename... _Views>
+ struct __zip_view_iter_cat
+ { };
+
+ template<bool _Const, typename... _Views>
+ requires __all_forward<_Const, _Views...>
+ struct __zip_view_iter_cat<_Const, _Views...>
+ { using iterator_category = input_iterator_tag; };
+ } // namespace __detail
+
+ template<input_range... _Vs>
+ requires (view<_Vs> && ...) && (sizeof...(_Vs) > 0)
+ template<bool _Const>
+ class zip_view<_Vs...>::_Iterator
+ : public __detail::__zip_view_iter_cat<_Const, _Vs...>
+ {
+ __detail::__tuple_or_pair_t<iterator_t<__detail::__maybe_const_t<_Const, _Vs>>...> _M_current;
+
+ constexpr explicit
+ _Iterator(decltype(_M_current) __current)
+ : _M_current(std::move(__current))
+ { }
+
+ static auto
+ _S_iter_concept()
+ {
+ if constexpr (__detail::__all_random_access<_Const, _Vs...>)
+ return random_access_iterator_tag{};
+ else if constexpr (__detail::__all_bidirectional<_Const, _Vs...>)
+ return bidirectional_iterator_tag{};
+ else if constexpr (__detail::__all_forward<_Const, _Vs...>)
+ return forward_iterator_tag{};
+ else
+ return input_iterator_tag{};
+ }
+
+ public:
+ // iterator_category defined in __zip_view_iter_cat
+ using iterator_concept = decltype(_S_iter_concept());
+ using value_type
+ = __detail::__tuple_or_pair_t<range_value_t<__detail::__maybe_const_t<_Const, _Vs>>...>;
+ using difference_type
+ = common_type_t<range_difference_t<__detail::__maybe_const_t<_Const, _Vs>>...>;
+
+ _Iterator() = default;
+
+ constexpr
+ _Iterator(_Iterator<!_Const> __i)
+ requires _Const
+ && (convertible_to<iterator_t<_Vs>,
+ iterator_t<__detail::__maybe_const_t<_Const, _Vs>>> && ...)
+ : _M_current(std::move(__i._M_current))
+ { }
+
+ constexpr auto
+ operator*() const
+ {
+ auto __f = [](auto& __i) -> decltype(auto) {
+ return *__i;
+ };
+ return __detail::__tuple_transform(__f, _M_current);
+ }
+
+ constexpr _Iterator&
+ operator++()
+ {
+ __detail::__tuple_for_each([](auto& __i) { ++__i; }, _M_current);
+ return *this;
+ }
+
+ constexpr void
+ operator++(int)
+ { ++*this; }
+
+ constexpr _Iterator
+ operator++(int)
+ requires __detail::__all_forward<_Const, _Vs...>
+ {
+ auto __tmp = *this;
+ ++*this;
+ return __tmp;
+ }
+
+ constexpr _Iterator&
+ operator--()
+ requires __detail::__all_bidirectional<_Const, _Vs...>
+ {
+ __detail::__tuple_for_each([](auto& __i) { --__i; }, _M_current);
+ return *this;
+ }
+
+ constexpr _Iterator
+ operator--(int)
+ requires __detail::__all_bidirectional<_Const, _Vs...>
+ {
+ auto __tmp = *this;
+ --*this;
+ return __tmp;
+ }
+
+ constexpr _Iterator&
+ operator+=(difference_type __x)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ {
+ auto __f = [&]<typename _It>(_It& __i) {
+ __i += iter_difference_t<_It>(__x);
+ };
+ __detail::__tuple_for_each(__f, _M_current);
+ return *this;
+ }
+
+ constexpr _Iterator&
+ operator-=(difference_type __x)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ {
+ auto __f = [&]<typename _It>(_It& __i) {
+ __i -= iter_difference_t<_It>(__x);
+ };
+ __detail::__tuple_for_each(__f, _M_current);
+ return *this;
+ }
+
+ constexpr auto
+ operator[](difference_type __n) const
+ requires __detail::__all_random_access<_Const, _Vs...>
+ {
+ auto __f = [&]<typename _It>(_It& __i) -> decltype(auto) {
+ return __i[iter_difference_t<_It>(__n)];
+ };
+ return __detail::__tuple_transform(__f, _M_current);
+ }
+
+ friend constexpr bool
+ operator==(const _Iterator& __x, const _Iterator& __y)
+ requires (equality_comparable<iterator_t<__detail::__maybe_const_t<_Const, _Vs>>> && ...)
+ {
+ if constexpr (__detail::__all_bidirectional<_Const, _Vs...>)
+ return __x._M_current == __y._M_current;
+ else
+ return [&]<size_t... _Is>(index_sequence<_Is...>) {
+ return ((std::get<_Is>(__x._M_current) == std::get<_Is>(__y._M_current)) || ...);
+ }(make_index_sequence<sizeof...(_Vs)>{});
+ }
+
+ friend constexpr bool
+ operator<(const _Iterator& __x, const _Iterator& __y)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ { return __x._M_current < __y._M_current; }
+
+ friend constexpr bool
+ operator>(const _Iterator& __x, const _Iterator& __y)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ { return __y < __x; }
+
+ friend constexpr bool
+ operator<=(const _Iterator& __x, const _Iterator& __y)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ { return !(__y < __x); }
+
+ friend constexpr bool
+ operator>=(const _Iterator& __x, const _Iterator& __y)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ { return !(__x < __y); }
+
+ friend constexpr auto
+ operator<=>(const _Iterator& __x, const _Iterator& __y)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ && (three_way_comparable<iterator_t<__detail::__maybe_const_t<_Const, _Vs>>> && ...)
+ { return __x._M_current <=> __y._M_current; }
+
+ friend constexpr _Iterator
+ operator+(const _Iterator& __i, difference_type __n)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ {
+ auto __r = __i;
+ __r += __n;
+ return __r;
+ }
+
+ friend constexpr _Iterator
+ operator+(difference_type __n, const _Iterator& __i)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ {
+ auto __r = __i;
+ __r += __n;
+ return __r;
+ }
+
+ friend constexpr _Iterator
+ operator-(const _Iterator& __i, difference_type __n)
+ requires __detail::__all_random_access<_Const, _Vs...>
+ {
+ auto __r = __i;
+ __r -= __n;
+ return __r;
+ }
+
+ friend constexpr difference_type
+ operator-(const _Iterator& __x, const _Iterator& __y)
+ requires (sized_sentinel_for<iterator_t<__detail::__maybe_const_t<_Const, _Vs>>,
+ iterator_t<__detail::__maybe_const_t<_Const, _Vs>>> && ...)
+ {
+ return [&]<size_t... _Is>(index_sequence<_Is...>) {
+ return ranges::min({difference_type(std::get<_Is>(__x._M_current)
+ - std::get<_Is>(__y._M_current))...},
+ ranges::less{},
+ [](difference_type __i) -> make_unsigned_t<difference_type> {
+ return __i < 0 ? -__i : __i;
+ });
+ }(make_index_sequence<sizeof...(_Vs)>{});
+ }
+
+ friend constexpr auto
+ iter_move(const _Iterator& __i)
+ { return __detail::__tuple_transform(ranges::iter_move, __i._M_current); }
+
+ friend constexpr void
+ iter_swap(const _Iterator& __l, const _Iterator& __r)
+ requires (indirectly_swappable<iterator_t<__detail::__maybe_const_t<_Const, _Vs>>> && ...)
+ {
+ [&]<size_t... _Is>(index_sequence<_Is...>) {
+ (ranges::iter_swap(std::get<_Is>(__l._M_current), std::get<_Is>(__r._M_current)), ...);
+ }(make_index_sequence<sizeof...(_Vs)>{});
+ }
+
+ friend class zip_view;
+ };
+
+ template<input_range... _Vs>
+ requires (view<_Vs> && ...) && (sizeof...(_Vs) > 0)
+ template<bool _Const>
+ class zip_view<_Vs...>::_Sentinel
+ {
+ __detail::__tuple_or_pair_t<sentinel_t<__detail::__maybe_const_t<_Const, _Vs>>...> _M_end;
+
+ constexpr explicit
+ _Sentinel(decltype(_M_end) __end)
+ : _M_end(__end)
+ { }
+
+ friend class zip_view;
+
+ public:
+ _Sentinel() = default;
+
+ constexpr
+ _Sentinel(_Sentinel<!_Const> __i)
+ requires _Const
+ && (convertible_to<sentinel_t<_Vs>,
+ sentinel_t<__detail::__maybe_const_t<_Const, _Vs>>> && ...)
+ : _M_end(std::move(__i._M_end))
+ { }
+
+ template<bool _OtherConst>
+ requires (sentinel_for<sentinel_t<__detail::__maybe_const_t<_Const, _Vs>>,
+ iterator_t<__detail::__maybe_const_t<_OtherConst, _Vs>>> && ...)
+ friend constexpr bool
+ operator==(const _Iterator<_OtherConst>& __x, const _Sentinel& __y)
+ {
+ return [&]<size_t... _Is>(index_sequence<_Is...>) {
+ return ((std::get<_Is>(__x._M_current) == std::get<_Is>(__y._M_end)) || ...);
+ }(make_index_sequence<sizeof...(_Vs)>{});
+ }
+
+ template<bool _OtherConst>
+ requires (sized_sentinel_for<sentinel_t<__detail::__maybe_const_t<_Const, _Vs>>,
+ iterator_t<__detail::__maybe_const_t<_OtherConst, _Vs>>> && ...)
+ friend constexpr auto
+ operator-(const _Iterator<_OtherConst>& __x, const _Sentinel& __y)
+ {
+ using _Ret
+ = common_type_t<range_difference_t<__detail::__maybe_const_t<_OtherConst, _Vs>>...>;
+ return [&]<size_t... _Is>(index_sequence<_Is...>) {
+ return ranges::min({_Ret(std::get<_Is>(__x._M_current) - std::get<_Is>(__y._M_end))...},
+ ranges::less{},
+ [](_Ret __i) -> make_unsigned_t<_Ret> {
+ return __i < 0 ? -__i : __i;
+ });
+ }(make_index_sequence<sizeof...(_Vs)>{});
+ }
+
+ template<bool _OtherConst>
+ requires (sized_sentinel_for<sentinel_t<__detail::__maybe_const_t<_Const, _Vs>>,
+ iterator_t<__detail::__maybe_const_t<_OtherConst, _Vs>>> && ...)
+ friend constexpr auto
+ operator-(const _Sentinel& __y, const _Iterator<_OtherConst>& __x)
+ { return -(__x - __y); }
+ };
+
+ namespace views
+ {
+ namespace __detail
+ {
+ template<typename... _Ts>
+ concept __can_zip_view
+ = requires { zip_view<all_t<_Ts>...>(std::declval<_Ts>()...); };
+ }
+
+ struct _Zip
+ {
+ template<typename... _Ts>
+ requires (sizeof...(_Ts) == 0 || __detail::__can_zip_view<_Ts...>)
+ [[nodiscard]]
+ constexpr auto
+ operator()(_Ts&&... __ts) const
+ {
+ if constexpr (sizeof...(_Ts) == 0)
+ return views::empty<tuple<>>;
+ else
+ return zip_view<all_t<_Ts>...>(std::forward<_Ts>(__ts)...);
+ }
+ };
+
+ inline constexpr _Zip zip;
+ }
+#endif // C++23
} // namespace ranges
namespace views = ranges::views;
git://gcc.gnu.org / gcc.git / blobdiff