| //===----------------------------------------------------------------------===// |
| // |
| // 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___ALGORITHM_ITERATOR_OPERATIONS_H |
| #define _LIBCPP___ALGORITHM_ITERATOR_OPERATIONS_H |
| |
| #include <__algorithm/iter_swap.h> |
| #include <__algorithm/ranges_iterator_concept.h> |
| #include <__config> |
| #include <__iterator/advance.h> |
| #include <__iterator/distance.h> |
| #include <__iterator/incrementable_traits.h> |
| #include <__iterator/iter_move.h> |
| #include <__iterator/iter_swap.h> |
| #include <__iterator/iterator_traits.h> |
| #include <__iterator/next.h> |
| #include <__iterator/prev.h> |
| #include <__iterator/readable_traits.h> |
| #include <__type_traits/enable_if.h> |
| #include <__type_traits/is_reference.h> |
| #include <__type_traits/is_same.h> |
| #include <__type_traits/remove_cvref.h> |
| #include <__utility/declval.h> |
| #include <__utility/forward.h> |
| #include <__utility/move.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _AlgPolicy> struct _IterOps; |
| |
| #if _LIBCPP_STD_VER >= 20 |
| struct _RangeAlgPolicy {}; |
| |
| template <> |
| struct _IterOps<_RangeAlgPolicy> { |
| |
| template <class _Iter> |
| using __value_type = iter_value_t<_Iter>; |
| |
| template <class _Iter> |
| using __iterator_category = ranges::__iterator_concept<_Iter>; |
| |
| template <class _Iter> |
| using __difference_type = iter_difference_t<_Iter>; |
| |
| static constexpr auto advance = ranges::advance; |
| static constexpr auto distance = ranges::distance; |
| static constexpr auto __iter_move = ranges::iter_move; |
| static constexpr auto iter_swap = ranges::iter_swap; |
| static constexpr auto next = ranges::next; |
| static constexpr auto prev = ranges::prev; |
| static constexpr auto __advance_to = ranges::advance; |
| }; |
| |
| #endif |
| |
| struct _ClassicAlgPolicy {}; |
| |
| template <> |
| struct _IterOps<_ClassicAlgPolicy> { |
| |
| template <class _Iter> |
| using __value_type = typename iterator_traits<_Iter>::value_type; |
| |
| template <class _Iter> |
| using __iterator_category = typename iterator_traits<_Iter>::iterator_category; |
| |
| template <class _Iter> |
| using __difference_type = typename iterator_traits<_Iter>::difference_type; |
| |
| // advance |
| template <class _Iter, class _Distance> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| static void advance(_Iter& __iter, _Distance __count) { |
| std::advance(__iter, __count); |
| } |
| |
| // distance |
| template <class _Iter> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| static typename iterator_traits<_Iter>::difference_type distance(_Iter __first, _Iter __last) { |
| return std::distance(__first, __last); |
| } |
| |
| template <class _Iter> |
| using __deref_t = decltype(*std::declval<_Iter&>()); |
| |
| template <class _Iter> |
| using __move_t = decltype(std::move(*std::declval<_Iter&>())); |
| |
| template <class _Iter> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| static void __validate_iter_reference() { |
| static_assert(is_same<__deref_t<_Iter>, typename iterator_traits<__remove_cvref_t<_Iter> >::reference>::value, |
| "It looks like your iterator's `iterator_traits<It>::reference` does not match the return type of " |
| "dereferencing the iterator, i.e., calling `*it`. This is undefined behavior according to [input.iterators] " |
| "and can lead to dangling reference issues at runtime, so we are flagging this."); |
| } |
| |
| // iter_move |
| template <class _Iter> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static |
| // If the result of dereferencing `_Iter` is a reference type, deduce the result of calling `std::move` on it. Note |
| // that the C++03 mode doesn't support `decltype(auto)` as the return type. |
| __enable_if_t< |
| is_reference<__deref_t<_Iter> >::value, |
| __move_t<_Iter> > |
| __iter_move(_Iter&& __i) { |
| __validate_iter_reference<_Iter>(); |
| |
| return std::move(*std::forward<_Iter>(__i)); |
| } |
| |
| template <class _Iter> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static |
| // If the result of dereferencing `_Iter` is a value type, deduce the return value of this function to also be a |
| // value -- otherwise, after `operator*` returns a temporary, this function would return a dangling reference to that |
| // temporary. Note that the C++03 mode doesn't support `auto` as the return type. |
| __enable_if_t< |
| !is_reference<__deref_t<_Iter> >::value, |
| __deref_t<_Iter> > |
| __iter_move(_Iter&& __i) { |
| __validate_iter_reference<_Iter>(); |
| |
| return *std::forward<_Iter>(__i); |
| } |
| |
| // iter_swap |
| template <class _Iter1, class _Iter2> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| static void iter_swap(_Iter1&& __a, _Iter2&& __b) { |
| std::iter_swap(std::forward<_Iter1>(__a), std::forward<_Iter2>(__b)); |
| } |
| |
| // next |
| template <class _Iterator> |
| _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| _Iterator next(_Iterator, _Iterator __last) { |
| return __last; |
| } |
| |
| template <class _Iter> |
| _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| __remove_cvref_t<_Iter> next(_Iter&& __it, |
| typename iterator_traits<__remove_cvref_t<_Iter> >::difference_type __n = 1) { |
| return std::next(std::forward<_Iter>(__it), __n); |
| } |
| |
| // prev |
| template <class _Iter> |
| _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| __remove_cvref_t<_Iter> prev(_Iter&& __iter, |
| typename iterator_traits<__remove_cvref_t<_Iter> >::difference_type __n = 1) { |
| return std::prev(std::forward<_Iter>(__iter), __n); |
| } |
| |
| template <class _Iter> |
| _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| void __advance_to(_Iter& __first, _Iter __last) { |
| __first = __last; |
| } |
| }; |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___ALGORITHM_ITERATOR_OPERATIONS_H |