| // -*- 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___ITERATOR_REVERSE_ITERATOR_H |
| #define _LIBCPP___ITERATOR_REVERSE_ITERATOR_H |
| |
| #include <__config> |
| #include <__compare/compare_three_way_result.h> |
| #include <__compare/three_way_comparable.h> |
| #include <__iterator/iterator.h> |
| #include <__iterator/iterator_traits.h> |
| #include <__memory/addressof.h> |
| #include <type_traits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| #pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _Tp, class = void> |
| struct __is_stashing_iterator : false_type {}; |
| |
| template <class _Tp> |
| struct __is_stashing_iterator<_Tp, typename __void_t<typename _Tp::__stashing_iterator_tag>::type> |
| : true_type {}; |
| |
| _LIBCPP_SUPPRESS_DEPRECATED_PUSH |
| template <class _Iter> |
| class _LIBCPP_TEMPLATE_VIS reverse_iterator |
| #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES) |
| : public iterator<typename iterator_traits<_Iter>::iterator_category, |
| typename iterator_traits<_Iter>::value_type, |
| typename iterator_traits<_Iter>::difference_type, |
| typename iterator_traits<_Iter>::pointer, |
| typename iterator_traits<_Iter>::reference> |
| #endif |
| { |
| _LIBCPP_SUPPRESS_DEPRECATED_POP |
| private: |
| #ifndef _LIBCPP_ABI_NO_ITERATOR_BASES |
| _Iter __t; // no longer used as of LWG #2360, not removed due to ABI break |
| #endif |
| |
| static_assert(!__is_stashing_iterator<_Iter>::value, |
| "The specified iterator type cannot be used with reverse_iterator; " |
| "Using stashing iterators with reverse_iterator causes undefined behavior"); |
| |
| protected: |
| _Iter current; |
| public: |
| typedef _Iter iterator_type; |
| typedef typename iterator_traits<_Iter>::difference_type difference_type; |
| typedef typename iterator_traits<_Iter>::reference reference; |
| typedef typename iterator_traits<_Iter>::pointer pointer; |
| typedef _If<__is_cpp17_random_access_iterator<_Iter>::value, |
| random_access_iterator_tag, |
| typename iterator_traits<_Iter>::iterator_category> iterator_category; |
| typedef typename iterator_traits<_Iter>::value_type value_type; |
| |
| #if _LIBCPP_STD_VER > 17 |
| typedef _If<__is_cpp17_random_access_iterator<_Iter>::value, |
| random_access_iterator_tag, |
| bidirectional_iterator_tag> iterator_concept; |
| #endif |
| |
| #ifndef _LIBCPP_ABI_NO_ITERATOR_BASES |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator() : __t(), current() {} |
| |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {} |
| |
| template <class _Up, class = __enable_if_t< |
| !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value |
| > > |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator(const reverse_iterator<_Up>& __u) |
| : __t(__u.base()), current(__u.base()) |
| { } |
| |
| template <class _Up, class = __enable_if_t< |
| !is_same<_Up, _Iter>::value && |
| is_convertible<_Up const&, _Iter>::value && |
| is_assignable<_Iter, _Up const&>::value |
| > > |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator& operator=(const reverse_iterator<_Up>& __u) { |
| __t = current = __u.base(); |
| return *this; |
| } |
| #else |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator() : current() {} |
| |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| explicit reverse_iterator(_Iter __x) : current(__x) {} |
| |
| template <class _Up, class = __enable_if_t< |
| !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value |
| > > |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator(const reverse_iterator<_Up>& __u) |
| : current(__u.base()) |
| { } |
| |
| template <class _Up, class = __enable_if_t< |
| !is_same<_Up, _Iter>::value && |
| is_convertible<_Up const&, _Iter>::value && |
| is_assignable<_Iter, _Up const&>::value |
| > > |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator& operator=(const reverse_iterator<_Up>& __u) { |
| current = __u.base(); |
| return *this; |
| } |
| #endif |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| _Iter base() const {return current;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reference operator*() const {_Iter __tmp = current; return *--__tmp;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| pointer operator->() const {return _VSTD::addressof(operator*());} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator& operator++() {--current; return *this;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator& operator--() {++current; return *this;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator operator+ (difference_type __n) const {return reverse_iterator(current - __n);} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator operator- (difference_type __n) const {return reverse_iterator(current + __n);} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reference operator[](difference_type __n) const {return *(*this + __n);} |
| }; |
| |
| template <class _Iter1, class _Iter2> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| bool |
| operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| { |
| return __x.base() == __y.base(); |
| } |
| |
| template <class _Iter1, class _Iter2> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| bool |
| operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| { |
| return __x.base() > __y.base(); |
| } |
| |
| template <class _Iter1, class _Iter2> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| bool |
| operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| { |
| return __x.base() != __y.base(); |
| } |
| |
| template <class _Iter1, class _Iter2> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| bool |
| operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| { |
| return __x.base() < __y.base(); |
| } |
| |
| template <class _Iter1, class _Iter2> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| bool |
| operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| { |
| return __x.base() <= __y.base(); |
| } |
| |
| template <class _Iter1, class _Iter2> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| bool |
| operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| { |
| return __x.base() >= __y.base(); |
| } |
| |
| #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) |
| template <class _Iter1, three_way_comparable_with<_Iter1> _Iter2> |
| _LIBCPP_HIDE_FROM_ABI constexpr |
| compare_three_way_result_t<_Iter1, _Iter2> |
| operator<=>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| { |
| return __y.base() <=> __x.base(); |
| } |
| #endif |
| |
| #ifndef _LIBCPP_CXX03_LANG |
| template <class _Iter1, class _Iter2> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| auto |
| operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| -> decltype(__y.base() - __x.base()) |
| { |
| return __y.base() - __x.base(); |
| } |
| #else |
| template <class _Iter1, class _Iter2> |
| inline _LIBCPP_INLINE_VISIBILITY |
| typename reverse_iterator<_Iter1>::difference_type |
| operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) |
| { |
| return __y.base() - __x.base(); |
| } |
| #endif |
| |
| template <class _Iter> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator<_Iter> |
| operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x) |
| { |
| return reverse_iterator<_Iter>(__x.base() - __n); |
| } |
| |
| #if _LIBCPP_STD_VER > 11 |
| template <class _Iter> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| reverse_iterator<_Iter> make_reverse_iterator(_Iter __i) |
| { |
| return reverse_iterator<_Iter>(__i); |
| } |
| #endif |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___ITERATOR_REVERSE_ITERATOR_H |