| // -*- 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 <__compare/compare_three_way_result.h> |
| #include <__compare/three_way_comparable.h> |
| #include <__concepts/convertible_to.h> |
| #include <__config> |
| #include <__iterator/concepts.h> |
| #include <__iterator/incrementable_traits.h> |
| #include <__iterator/iter_move.h> |
| #include <__iterator/iter_swap.h> |
| #include <__iterator/iterator.h> |
| #include <__iterator/iterator_traits.h> |
| #include <__iterator/prev.h> |
| #include <__iterator/readable_traits.h> |
| #include <__memory/addressof.h> |
| #include <__utility/move.h> |
| #include <type_traits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| _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 |
| |
| #if _LIBCPP_STD_VER > 17 |
| static_assert(__is_cpp17_bidirectional_iterator<_Iter>::value || bidirectional_iterator<_Iter>, |
| "reverse_iterator<It> requires It to be a bidirectional iterator."); |
| #endif // _LIBCPP_STD_VER > 17 |
| |
| protected: |
| _Iter current; |
| public: |
| using iterator_type = _Iter; |
| |
| using iterator_category = _If<__is_cpp17_random_access_iterator<_Iter>::value, |
| random_access_iterator_tag, |
| typename iterator_traits<_Iter>::iterator_category>; |
| using pointer = typename iterator_traits<_Iter>::pointer; |
| #if _LIBCPP_STD_VER > 17 |
| using iterator_concept = _If<__is_cpp17_random_access_iterator<_Iter>::value, |
| random_access_iterator_tag, |
| bidirectional_iterator_tag>; |
| using value_type = iter_value_t<_Iter>; |
| using difference_type = iter_difference_t<_Iter>; |
| using reference = iter_reference_t<_Iter>; |
| #else |
| using value_type = typename iterator_traits<_Iter>::value_type; |
| using difference_type = typename iterator_traits<_Iter>::difference_type; |
| using reference = typename iterator_traits<_Iter>::reference; |
| #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;} |
| |
| #if _LIBCPP_STD_VER > 17 |
| _LIBCPP_INLINE_VISIBILITY |
| constexpr pointer operator->() const |
| requires is_pointer_v<_Iter> || requires(const _Iter i) { i.operator->(); } |
| { |
| if constexpr (is_pointer_v<_Iter>) { |
| return std::prev(current); |
| } else { |
| return std::prev(current).operator->(); |
| } |
| } |
| #else |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| pointer operator->() const { |
| return std::addressof(operator*()); |
| } |
| #endif // _LIBCPP_STD_VER > 17 |
| |
| _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);} |
| |
| #if _LIBCPP_STD_VER > 17 |
| _LIBCPP_HIDE_FROM_ABI friend constexpr |
| iter_rvalue_reference_t<_Iter> iter_move(const reverse_iterator& __i) |
| noexcept(is_nothrow_copy_constructible_v<_Iter> && |
| noexcept(ranges::iter_move(--declval<_Iter&>()))) { |
| auto __tmp = __i.base(); |
| return ranges::iter_move(--__tmp); |
| } |
| |
| template <indirectly_swappable<_Iter> _Iter2> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr |
| void iter_swap(const reverse_iterator& __x, const reverse_iterator<_Iter2>& __y) |
| noexcept(is_nothrow_copy_constructible_v<_Iter> && |
| is_nothrow_copy_constructible_v<_Iter2> && |
| noexcept(ranges::iter_swap(--declval<_Iter&>(), --declval<_Iter2&>()))) { |
| auto __xtmp = __x.base(); |
| auto __ytmp = __y.base(); |
| ranges::iter_swap(--__xtmp, --__ytmp); |
| } |
| #endif // _LIBCPP_STD_VER > 17 |
| }; |
| |
| 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) |
| #if _LIBCPP_STD_VER > 17 |
| requires requires { |
| { __x.base() == __y.base() } -> convertible_to<bool>; |
| } |
| #endif // _LIBCPP_STD_VER > 17 |
| { |
| 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) |
| #if _LIBCPP_STD_VER > 17 |
| requires requires { |
| { __x.base() > __y.base() } -> convertible_to<bool>; |
| } |
| #endif // _LIBCPP_STD_VER > 17 |
| { |
| 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) |
| #if _LIBCPP_STD_VER > 17 |
| requires requires { |
| { __x.base() != __y.base() } -> convertible_to<bool>; |
| } |
| #endif // _LIBCPP_STD_VER > 17 |
| { |
| 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) |
| #if _LIBCPP_STD_VER > 17 |
| requires requires { |
| { __x.base() < __y.base() } -> convertible_to<bool>; |
| } |
| #endif // _LIBCPP_STD_VER > 17 |
| { |
| 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) |
| #if _LIBCPP_STD_VER > 17 |
| requires requires { |
| { __x.base() <= __y.base() } -> convertible_to<bool>; |
| } |
| #endif // _LIBCPP_STD_VER > 17 |
| { |
| 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) |
| #if _LIBCPP_STD_VER > 17 |
| requires requires { |
| { __x.base() >= __y.base() } -> convertible_to<bool>; |
| } |
| #endif // _LIBCPP_STD_VER > 17 |
| { |
| return __x.base() >= __y.base(); |
| } |
| |
| #if _LIBCPP_STD_VER > 17 |
| 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 // _LIBCPP_STD_VER > 17 |
| |
| #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 > 17 |
| template <class _Iter1, class _Iter2> |
| requires (!sized_sentinel_for<_Iter1, _Iter2>) |
| inline constexpr bool disable_sized_sentinel_for<reverse_iterator<_Iter1>, reverse_iterator<_Iter2>> = true; |
| #endif // _LIBCPP_STD_VER > 17 |
| |
| #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 |