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author | Patrick Palka <ppalka@redhat.com> | 2022-08-31 15:09:10 -0400 |
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committer | Patrick Palka <ppalka@redhat.com> | 2022-08-31 15:09:10 -0400 |
commit | f956cadc292aec42ceeba1e4835ad795c9aab5c2 (patch) | |
tree | de02195a2e2bd37472d6ff5d5198d3e3ec909ef4 | |
parent | 4d5660907c2b4c301fcbdc3dc713879fa31afec0 (diff) | |
download | gcc-f956cadc292aec42ceeba1e4835ad795c9aab5c2.zip gcc-f956cadc292aec42ceeba1e4835ad795c9aab5c2.tar.gz gcc-f956cadc292aec42ceeba1e4835ad795c9aab5c2.tar.bz2 |
libstdc++: Implement ranges::adjacent_view from P2321R2
libstdc++-v3/ChangeLog:
* include/std/ranges (adjacent_view): Define.
(enable_borrowed_range<adjacent_view>): Define.
(__detail::__repeated_tuple): Define.
(adjacent_view::_Iterator): Define.
(adjacent_view::_Sentinel): Define.
(views::__detail::__can_adjacent_view): Define.
(views::_Adjacent): Define.
(views::adjacent): Define.
(views::pairwise): Define.
* testsuite/std/ranges/adaptors/adjacent/1.cc: New test.
-rw-r--r-- | libstdc++-v3/include/std/ranges | 358 | ||||
-rw-r--r-- | libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc | 110 |
2 files changed, 468 insertions, 0 deletions
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index 6e2e561..2352aad 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -5081,6 +5081,364 @@ namespace views::__adaptor inline constexpr _ZipTransform zip_transform; } + + template<forward_range _Vp, size_t _Nm> + requires view<_Vp> && (_Nm > 0) + class adjacent_view : public view_interface<adjacent_view<_Vp, _Nm>> + { + _Vp _M_base = _Vp(); + + template<bool> class _Iterator; + template<bool> class _Sentinel; + + struct __as_sentinel + { }; + + public: + adjacent_view() requires default_initializable<_Vp> = default; + + constexpr explicit + adjacent_view(_Vp __base) + : _M_base(std::move(__base)) + { } + + constexpr auto + begin() requires (!__detail::__simple_view<_Vp>) + { return _Iterator<false>(ranges::begin(_M_base), ranges::end(_M_base)); } + + constexpr auto + begin() const requires range<const _Vp> + { return _Iterator<true>(ranges::begin(_M_base), ranges::end(_M_base)); } + + constexpr auto + end() requires (!__detail::__simple_view<_Vp>) + { + if constexpr (common_range<_Vp>) + return _Iterator<false>(__as_sentinel{}, ranges::begin(_M_base), ranges::end(_M_base)); + else + return _Sentinel<false>(ranges::end(_M_base)); + } + + constexpr auto + end() const requires range<const _Vp> + { + if constexpr (common_range<const _Vp>) + return _Iterator<true>(__as_sentinel{}, ranges::begin(_M_base), ranges::end(_M_base)); + else + return _Sentinel<true>(ranges::end(_M_base)); + } + + constexpr auto + size() requires sized_range<_Vp> + { + using _ST = decltype(ranges::size(_M_base)); + using _CT = common_type_t<_ST, size_t>; + auto __sz = static_cast<_CT>(ranges::size(_M_base)); + __sz -= std::min<_CT>(__sz, _Nm - 1); + return static_cast<_ST>(__sz); + } + + constexpr auto + size() const requires sized_range<const _Vp> + { + using _ST = decltype(ranges::size(_M_base)); + using _CT = common_type_t<_ST, size_t>; + auto __sz = static_cast<_CT>(ranges::size(_M_base)); + __sz -= std::min<_CT>(__sz, _Nm - 1); + return static_cast<_ST>(__sz); + } + }; + + template<typename _Vp, size_t _Nm> + inline constexpr bool enable_borrowed_range<adjacent_view<_Vp, _Nm>> + = enable_borrowed_range<_Vp>; + + namespace __detail + { + // Yields tuple<_Tp, ..., _Tp> with _Nm elements. + template<typename _Tp, size_t _Nm> + using __repeated_tuple = decltype(std::tuple_cat(std::declval<array<_Tp, _Nm>>())); + } + + template<forward_range _Vp, size_t _Nm> + requires view<_Vp> && (_Nm > 0) + template<bool _Const> + class adjacent_view<_Vp, _Nm>::_Iterator + { + using _Base = __detail::__maybe_const_t<_Const, _Vp>; + array<iterator_t<_Base>, _Nm> _M_current = array<iterator_t<_Base>, _Nm>(); + + constexpr + _Iterator(iterator_t<_Base> __first, sentinel_t<_Base> __last) + { + for (auto& __i : _M_current) + { + __i = __first; + ranges::advance(__first, 1, __last); + } + } + + constexpr + _Iterator(__as_sentinel, iterator_t<_Base> __first, iterator_t<_Base> __last) + { + if constexpr (!bidirectional_range<_Base>) + for (auto& __it : _M_current) + __it = __last; + else + for (size_t __i = 0; __i < _Nm; ++__i) + { + _M_current[_Nm - 1 - __i] = __last; + ranges::advance(__last, -1, __first); + } + } + + static auto + _S_iter_concept() + { + if constexpr (random_access_range<_Base>) + return random_access_iterator_tag{}; + else if constexpr (bidirectional_range<_Base>) + return bidirectional_iterator_tag{}; + else + return forward_iterator_tag{}; + } + + friend class adjacent_view; + + public: + using iterator_category = input_iterator_tag; + using iterator_concept = decltype(_S_iter_concept()); + using value_type = conditional_t<_Nm == 2, + pair<range_value_t<_Base>, range_value_t<_Base>>, + __detail::__repeated_tuple<range_value_t<_Base>, _Nm>>; + using difference_type = range_difference_t<_Base>; + + _Iterator() = default; + + constexpr + _Iterator(_Iterator<!_Const> __i) + requires _Const && convertible_to<iterator_t<_Vp>, iterator_t<_Base>> + { + for (size_t __j = 0; __j < _Nm; ++__j) + _M_current[__j] = std::move(__i[__j]); + } + + constexpr auto + operator*() const + { + auto __f = [](auto& __i) -> decltype(auto) { return *__i; }; + return __detail::__tuple_transform(__f, _M_current); + } + + constexpr _Iterator& + operator++() + { + for (auto& __i : _M_current) + ++__i; + return *this; + } + + constexpr _Iterator + operator++(int) + { + auto __tmp = *this; + ++*this; + return __tmp; + } + + constexpr _Iterator& + operator--() requires bidirectional_range<_Base> + { + for (auto& __i : _M_current) + --__i; + return *this; + } + + constexpr _Iterator + operator--(int) requires bidirectional_range<_Base> + { + auto __tmp = *this; + --*this; + return __tmp; + } + + constexpr _Iterator& + operator+=(difference_type __x) + requires random_access_range<_Base> + { + for (auto& __i : _M_current) + __i += __x; + return *this; + } + + constexpr _Iterator& + operator-=(difference_type __x) + requires random_access_range<_Base> + { + for (auto& __i : _M_current) + __i -= __x; + return *this; + } + + constexpr auto + operator[](difference_type __n) const + requires random_access_range<_Base> + { + auto __f = [&](auto& __i) -> decltype(auto) { return __i[__n]; }; + return __detail::__tuple_transform(__f, _M_current); + } + + friend constexpr bool + operator==(const _Iterator& __x, const _Iterator& __y) + { return __x._M_current.back() == __y._M_current.back(); } + + friend constexpr bool + operator<(const _Iterator& __x, const _Iterator& __y) + requires random_access_range<_Base> + { return __x._M_current.back() < __y._M_current.back(); } + + friend constexpr bool + operator>(const _Iterator& __x, const _Iterator& __y) + requires random_access_range<_Base> + { return __y < __x; } + + friend constexpr bool + operator<=(const _Iterator& __x, const _Iterator& __y) + requires random_access_range<_Base> + { return !(__y < __x); } + + friend constexpr bool + operator>=(const _Iterator& __x, const _Iterator& __y) + requires random_access_range<_Base> + { return !(__x < __y); } + + friend constexpr auto + operator<=>(const _Iterator& __x, const _Iterator& __y) + requires random_access_range<_Base> + && three_way_comparable<iterator_t<_Base>> + { return __x._M_current.back() <=> __y._M_current.back(); } + + friend constexpr _Iterator + operator+(const _Iterator& __i, difference_type __n) + requires random_access_range<_Base> + { + auto __r = __i; + __r += __n; + return __r; + } + + friend constexpr _Iterator + operator+(difference_type __n, const _Iterator& __i) + requires random_access_range<_Base> + { + auto __r = __i; + __r += __n; + return __r; + } + + friend constexpr _Iterator + operator-(const _Iterator& __i, difference_type __n) + requires random_access_range<_Base> + { + auto __r = __i; + __r -= __n; + return __r; + } + + friend constexpr difference_type + operator-(const _Iterator& __x, const _Iterator& __y) + requires sized_sentinel_for<iterator_t<_Base>, iterator_t<_Base>> + { return __x._M_current.back() - __y._M_current.back(); } + + 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<_Base>> + { + for (size_t __i = 0; __i < _Nm; __i++) + ranges::iter_swap(__l._M_current[__i], __r._M_current[__i]); + } + }; + + template<forward_range _Vp, size_t _Nm> + requires view<_Vp> && (_Nm > 0) + template<bool _Const> + class adjacent_view<_Vp, _Nm>::_Sentinel + { + using _Base = __detail::__maybe_const_t<_Const, _Vp>; + + sentinel_t<_Base> _M_end = sentinel_t<_Base>(); + + constexpr explicit + _Sentinel(sentinel_t<_Base> __end) + : _M_end(__end) + { } + + friend class adjacent_view; + + public: + _Sentinel() = default; + + constexpr + _Sentinel(_Sentinel<!_Const> __i) + requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> + : _M_end(std::move(__i._M_end)) + { } + + template<bool _OtherConst> + requires sentinel_for<sentinel_t<_Base>, + iterator_t<__detail::__maybe_const_t<_OtherConst, _Vp>>> + friend constexpr bool + operator==(const _Iterator<_OtherConst>& __x, const _Sentinel& __y) + { return __x._M_current.back() == __y._M_end; } + + template<bool _OtherConst> + requires sized_sentinel_for<sentinel_t<_Base>, + iterator_t<__detail::__maybe_const_t<_OtherConst, _Vp>>> + friend constexpr range_difference_t<__detail::__maybe_const_t<_OtherConst, _Vp>> + operator-(const _Iterator<_OtherConst>& __x, const _Sentinel& __y) + { return __x._M_current.back() - __y._M_end; } + + template<bool _OtherConst> + requires sized_sentinel_for<sentinel_t<_Base>, + iterator_t<__detail::__maybe_const_t<_OtherConst, _Vp>>> + friend constexpr range_difference_t<__detail::__maybe_const_t<_OtherConst, _Vp>> + operator-(const _Sentinel& __y, const _Iterator<_OtherConst>& __x) + { return __y._M_end - __x._M_current.back(); } + }; + + namespace views + { + namespace __detail + { + template<size_t _Nm, typename _Range> + concept __can_adjacent_view + = requires { adjacent_view<all_t<_Range>, _Nm>(std::declval<_Range>()); }; + } + + template<size_t _Nm> + struct _Adjacent : __adaptor::_RangeAdaptorClosure + { + template<viewable_range _Range> + requires (_Nm == 0) || __detail::__can_adjacent_view<_Nm, _Range> + constexpr auto + operator() [[nodiscard]] (_Range&& __r) const + { + if constexpr (_Nm == 0) + return views::empty<tuple<>>; + else + return adjacent_view<all_t<_Range>, _Nm>(std::forward<_Range>(__r)); + } + }; + + template<size_t _Nm> + inline constexpr _Adjacent<_Nm> adjacent; + + inline constexpr auto pairwise = adjacent<2>; + } #endif // C++23 } // namespace ranges diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc new file mode 100644 index 0000000..9829f79 --- /dev/null +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc @@ -0,0 +1,110 @@ +// { dg-options "-std=gnu++23" } +// { dg-do run { target c++23 } } + +#include <ranges> +#include <algorithm> +#include <utility> +#include <testsuite_hooks.h> +#include <testsuite_iterators.h> + +namespace ranges = std::ranges; +namespace views = std::views; + +constexpr bool +test01() +{ + static_assert(ranges::empty(std::array{1, 2, 3} | views::adjacent<0>)); + + auto v1 = std::array{1, 2} | views::adjacent<1>; + const auto i0 = v1.begin(), i1 = v1.begin() + 1; + VERIFY( i0 + 1 - 1 == i0 ); + VERIFY( i0 < i1 ); + VERIFY( i1 < v1.end() ); + VERIFY( i1 - i0 == 1 ); + VERIFY( i0 - i1 == -1 ); + VERIFY( v1.end() - i1 == 1 ); + VERIFY( i1 - v1.end() == -1 ); + ranges::iter_swap(i0, i1); + VERIFY( ranges::equal(std::move(v1) | views::keys, (int[]){2, 1}) ); + + int x[] = {1, 2, 3, 4}; + auto v2 = x | views::pairwise; + auto i2 = v2.begin(); + i2 += 2; + i2 -= -1; + VERIFY( i2 == v2.end() ); + VERIFY( ranges::size(v2) == 3 ); + VERIFY( ranges::size(std::as_const(v2)) == 3 ); + VERIFY( ranges::equal(v2 | views::keys, (int[]){1, 2, 3}) ); + VERIFY( ranges::equal(v2 | views::values, (int[]){2, 3, 4}) ); + + int y[] = {1, 2, 3, 4, 5}; + const auto v3 = y | views::adjacent<3>; + VERIFY( ranges::size(v3) == 3 ); + for (unsigned i = 0; i < ranges::size(x); i++) + { + VERIFY( &std::get<0>(v3[i]) == &y[i] + 0 ); + VERIFY( &std::get<1>(v3[i]) == &y[i] + 1 ); + VERIFY( &std::get<2>(v3[i]) == &y[i] + 2 ); + } + + const auto v5 = y | views::adjacent<5>; + VERIFY( ranges::equal(v5, views::single(std::make_tuple(1, 2, 3, 4, 5))) ); + + const auto v6 = y | views::adjacent<6>; + VERIFY( ranges::empty(v6) ); + + const auto v0 = y | views::adjacent<0>; + VERIFY( ranges::empty(v0) ); + + return true; +} + +constexpr bool +test02() +{ + using __gnu_test::test_input_range; + using __gnu_test::test_forward_range; + using __gnu_test::test_random_access_range; + + using ty1 = ranges::adjacent_view<views::all_t<test_forward_range<int>>, 2>; + static_assert(ranges::forward_range<ty1>); + static_assert(!ranges::bidirectional_range<ty1>); + static_assert(!ranges::sized_range<ty1>); + + using ty2 = ranges::adjacent_view<views::all_t<test_random_access_range<int>>, 3>; + static_assert(ranges::random_access_range<ty2>); + static_assert(ranges::sized_range<ty2>); + + return true; +} + +constexpr bool +test03() +{ + auto v = views::iota(0, 4) | views::filter([](auto) { return true; }) | views::pairwise; + using ty = decltype(v); + static_assert(ranges::forward_range<ty>); + static_assert(ranges::common_range<ty>); + static_assert(!ranges::sized_range<ty>); + VERIFY( v.begin() == v.begin() ); + VERIFY( v.begin() != v.end() ); + VERIFY( ranges::next(v.begin(), 3) == v.end() ); + auto it = v.begin(); + ++it; + it++; + VERIFY( ranges::next(it) == v.end() ); + it--; + --it; + VERIFY( it == v.begin() ); + + return true; +} + +int +main() +{ + static_assert(test01()); + static_assert(test02()); + static_assert(test03()); +} |