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Diffstat (limited to 'contrib/llvm-project/libcxx/include/__ranges/transform_view.h')
-rw-r--r-- | contrib/llvm-project/libcxx/include/__ranges/transform_view.h | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__ranges/transform_view.h b/contrib/llvm-project/libcxx/include/__ranges/transform_view.h new file mode 100644 index 000000000000..4243dc0366e9 --- /dev/null +++ b/contrib/llvm-project/libcxx/include/__ranges/transform_view.h @@ -0,0 +1,408 @@ +// -*- C++ -*- +//===----------------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +#ifndef _LIBCPP___RANGES_TRANSFORM_VIEW_H +#define _LIBCPP___RANGES_TRANSFORM_VIEW_H + +#include <__config> +#include <__iterator/concepts.h> +#include <__iterator/iter_swap.h> +#include <__iterator/iterator_traits.h> +#include <__ranges/access.h> +#include <__ranges/all.h> +#include <__ranges/concepts.h> +#include <__ranges/copyable_box.h> +#include <__ranges/empty.h> +#include <__ranges/size.h> +#include <__ranges/view_interface.h> +#include <concepts> +#include <type_traits> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +#pragma GCC system_header +#endif + +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + +_LIBCPP_BEGIN_NAMESPACE_STD + +#if !defined(_LIBCPP_HAS_NO_RANGES) + +namespace ranges { + +template<class _View, class _Fn> +concept __transform_view_constraints = + view<_View> && is_object_v<_Fn> && + regular_invocable<_Fn&, range_reference_t<_View>> && + __referenceable<invoke_result_t<_Fn&, range_reference_t<_View>>>; + +template<input_range _View, copy_constructible _Fn> + requires __transform_view_constraints<_View, _Fn> +class transform_view : public view_interface<transform_view<_View, _Fn>> { + template<bool> class __iterator; + template<bool> class __sentinel; + + [[no_unique_address]] __copyable_box<_Fn> __func_; + [[no_unique_address]] _View __base_ = _View(); + +public: + _LIBCPP_HIDE_FROM_ABI + transform_view() + requires default_initializable<_View> && default_initializable<_Fn> = default; + + _LIBCPP_HIDE_FROM_ABI + constexpr transform_view(_View __base, _Fn __func) + : __func_(_VSTD::in_place, _VSTD::move(__func)), __base_(_VSTD::move(__base)) {} + + _LIBCPP_HIDE_FROM_ABI + constexpr _View base() const& requires copy_constructible<_View> { return __base_; } + _LIBCPP_HIDE_FROM_ABI + constexpr _View base() && { return _VSTD::move(__base_); } + + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator<false> begin() { + return __iterator<false>{*this, ranges::begin(__base_)}; + } + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator<true> begin() const + requires range<const _View> && + regular_invocable<const _Fn&, range_reference_t<const _View>> + { + return __iterator<true>(*this, ranges::begin(__base_)); + } + + _LIBCPP_HIDE_FROM_ABI + constexpr __sentinel<false> end() { + return __sentinel<false>(ranges::end(__base_)); + } + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator<false> end() + requires common_range<_View> + { + return __iterator<false>(*this, ranges::end(__base_)); + } + _LIBCPP_HIDE_FROM_ABI + constexpr __sentinel<true> end() const + requires range<const _View> && + regular_invocable<const _Fn&, range_reference_t<const _View>> + { + return __sentinel<true>(ranges::end(__base_)); + } + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator<true> end() const + requires common_range<const _View> && + regular_invocable<const _Fn&, range_reference_t<const _View>> + { + return __iterator<true>(*this, ranges::end(__base_)); + } + + _LIBCPP_HIDE_FROM_ABI + constexpr auto size() requires sized_range<_View> { return ranges::size(__base_); } + _LIBCPP_HIDE_FROM_ABI + constexpr auto size() const requires sized_range<const _View> { return ranges::size(__base_); } +}; + +template<class _Range, class _Fn> +transform_view(_Range&&, _Fn) -> transform_view<views::all_t<_Range>, _Fn>; + +template<class _View> +struct __transform_view_iterator_concept { using type = input_iterator_tag; }; + +template<random_access_range _View> +struct __transform_view_iterator_concept<_View> { using type = random_access_iterator_tag; }; + +template<bidirectional_range _View> +struct __transform_view_iterator_concept<_View> { using type = bidirectional_iterator_tag; }; + +template<forward_range _View> +struct __transform_view_iterator_concept<_View> { using type = forward_iterator_tag; }; + +template<class, class> +struct __transform_view_iterator_category_base {}; + +template<forward_range _View, class _Fn> +struct __transform_view_iterator_category_base<_View, _Fn> { + using _Cat = typename iterator_traits<iterator_t<_View>>::iterator_category; + + using iterator_category = conditional_t< + is_lvalue_reference_v<invoke_result_t<_Fn&, range_reference_t<_View>>>, + conditional_t< + derived_from<_Cat, contiguous_iterator_tag>, + random_access_iterator_tag, + _Cat + >, + input_iterator_tag + >; +}; + +template<input_range _View, copy_constructible _Fn> + requires __transform_view_constraints<_View, _Fn> +template<bool _Const> +class transform_view<_View, _Fn>::__iterator + : public __transform_view_iterator_category_base<_View, _Fn> { + + using _Parent = __maybe_const<_Const, transform_view>; + using _Base = __maybe_const<_Const, _View>; + + _Parent *__parent_ = nullptr; + + template<bool> + friend class transform_view<_View, _Fn>::__iterator; + + template<bool> + friend class transform_view<_View, _Fn>::__sentinel; + +public: + iterator_t<_Base> __current_ = iterator_t<_Base>(); + + using iterator_concept = typename __transform_view_iterator_concept<_View>::type; + using value_type = remove_cvref_t<invoke_result_t<_Fn&, range_reference_t<_Base>>>; + using difference_type = range_difference_t<_Base>; + + _LIBCPP_HIDE_FROM_ABI + __iterator() requires default_initializable<iterator_t<_Base>> = default; + + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator(_Parent& __parent, iterator_t<_Base> __current) + : __parent_(_VSTD::addressof(__parent)), __current_(_VSTD::move(__current)) {} + + // Note: `__i` should always be `__iterator<false>`, but directly using + // `__iterator<false>` is ill-formed when `_Const` is false + // (see http://wg21.link/class.copy.ctor#5). + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator(__iterator<!_Const> __i) + requires _Const && convertible_to<iterator_t<_View>, iterator_t<_Base>> + : __parent_(__i.__parent_), __current_(_VSTD::move(__i.__current_)) {} + + _LIBCPP_HIDE_FROM_ABI + constexpr iterator_t<_Base> base() const& + requires copyable<iterator_t<_Base>> + { + return __current_; + } + + _LIBCPP_HIDE_FROM_ABI + constexpr iterator_t<_Base> base() && { + return _VSTD::move(__current_); + } + + _LIBCPP_HIDE_FROM_ABI + constexpr decltype(auto) operator*() const + noexcept(noexcept(_VSTD::invoke(*__parent_->__func_, *__current_))) + { + return _VSTD::invoke(*__parent_->__func_, *__current_); + } + + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator& operator++() { + ++__current_; + return *this; + } + + _LIBCPP_HIDE_FROM_ABI + constexpr void operator++(int) { ++__current_; } + + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator operator++(int) + requires forward_range<_Base> + { + auto __tmp = *this; + ++*this; + return __tmp; + } + + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator& operator--() + requires bidirectional_range<_Base> + { + --__current_; + return *this; + } + + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator operator--(int) + requires bidirectional_range<_Base> + { + auto __tmp = *this; + --*this; + return __tmp; + } + + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator& operator+=(difference_type __n) + requires random_access_range<_Base> + { + __current_ += __n; + return *this; + } + + _LIBCPP_HIDE_FROM_ABI + constexpr __iterator& operator-=(difference_type __n) + requires random_access_range<_Base> + { + __current_ -= __n; + return *this; + } + + _LIBCPP_HIDE_FROM_ABI + constexpr decltype(auto) operator[](difference_type __n) const + noexcept(noexcept(_VSTD::invoke(*__parent_->__func_, __current_[__n]))) + requires random_access_range<_Base> + { + return _VSTD::invoke(*__parent_->__func_, __current_[__n]); + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr bool operator==(const __iterator& __x, const __iterator& __y) + requires equality_comparable<iterator_t<_Base>> + { + return __x.__current_ == __y.__current_; + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr bool operator<(const __iterator& __x, const __iterator& __y) + requires random_access_range<_Base> + { + return __x.__current_ < __y.__current_; + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr bool operator>(const __iterator& __x, const __iterator& __y) + requires random_access_range<_Base> + { + return __x.__current_ > __y.__current_; + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr bool operator<=(const __iterator& __x, const __iterator& __y) + requires random_access_range<_Base> + { + return __x.__current_ <= __y.__current_; + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr bool operator>=(const __iterator& __x, const __iterator& __y) + requires random_access_range<_Base> + { + return __x.__current_ >= __y.__current_; + } + +// TODO: Fix this as soon as soon as three_way_comparable is implemented. +// _LIBCPP_HIDE_FROM_ABI +// friend constexpr auto operator<=>(const __iterator& __x, const __iterator& __y) +// requires random_access_range<_Base> && three_way_comparable<iterator_t<_Base>> +// { +// return __x.__current_ <=> __y.__current_; +// } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr __iterator operator+(__iterator __i, difference_type __n) + requires random_access_range<_Base> + { + return __iterator{*__i.__parent_, __i.__current_ + __n}; + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr __iterator operator+(difference_type __n, __iterator __i) + requires random_access_range<_Base> + { + return __iterator{*__i.__parent_, __i.__current_ + __n}; + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr __iterator operator-(__iterator __i, difference_type __n) + requires random_access_range<_Base> + { + return __iterator{*__i.__parent_, __i.__current_ - __n}; + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr difference_type operator-(const __iterator& __x, const __iterator& __y) + requires sized_sentinel_for<iterator_t<_Base>, iterator_t<_Base>> + { + return __x.__current_ - __y.__current_; + } + + _LIBCPP_HIDE_FROM_ABI + friend constexpr decltype(auto) iter_move(const __iterator& __i) + noexcept(noexcept(*__i)) + { + if constexpr (is_lvalue_reference_v<decltype(*__i)>) + return _VSTD::move(*__i); + else + return *__i; + } +}; + +template<input_range _View, copy_constructible _Fn> + requires __transform_view_constraints<_View, _Fn> +template<bool _Const> +class transform_view<_View, _Fn>::__sentinel { + using _Parent = __maybe_const<_Const, transform_view>; + using _Base = __maybe_const<_Const, _View>; + + sentinel_t<_Base> __end_ = sentinel_t<_Base>(); + + template<bool> + friend class transform_view<_View, _Fn>::__iterator; + + template<bool> + friend class transform_view<_View, _Fn>::__sentinel; + +public: + _LIBCPP_HIDE_FROM_ABI + __sentinel() = default; + + _LIBCPP_HIDE_FROM_ABI + constexpr explicit __sentinel(sentinel_t<_Base> __end) : __end_(__end) {} + + // Note: `__i` should always be `__sentinel<false>`, but directly using + // `__sentinel<false>` is ill-formed when `_Const` is false + // (see http://wg21.link/class.copy.ctor#5). + _LIBCPP_HIDE_FROM_ABI + constexpr __sentinel(__sentinel<!_Const> __i) + requires _Const && convertible_to<sentinel_t<_View>, sentinel_t<_Base>> + : __end_(_VSTD::move(__i.__end_)) {} + + _LIBCPP_HIDE_FROM_ABI + constexpr sentinel_t<_Base> base() const { return __end_; } + + template<bool _OtherConst> + requires sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>> + _LIBCPP_HIDE_FROM_ABI + friend constexpr bool operator==(const __iterator<_OtherConst>& __x, const __sentinel& __y) { + return __x.__current_ == __y.__end_; + } + + template<bool _OtherConst> + requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>> + _LIBCPP_HIDE_FROM_ABI + friend constexpr range_difference_t<__maybe_const<_OtherConst, _View>> + operator-(const __iterator<_OtherConst>& __x, const __sentinel& __y) { + return __x.__current_ - __y.__end_; + } + + template<bool _OtherConst> + requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>> + _LIBCPP_HIDE_FROM_ABI + friend constexpr range_difference_t<__maybe_const<_OtherConst, _View>> + operator-(const __sentinel& __x, const __iterator<_OtherConst>& __y) { + return __x.__end_ - __y.__current_; + } +}; + +} // namespace ranges + +#endif // !defined(_LIBCPP_HAS_NO_RANGES) + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___RANGES_TRANSFORM_VIEW_H |